HDDS-825. Code cleanup based on messages from ErrorProne.

Contributed by Anu Engineer.

hadoop-hdds/client/src/main/java/org/apache/hadoop/hdds/scm/XceiverClientGrpc.java

@@ -296,6 +296,7 @@ public void createPipeline() {
     // For stand alone pipeline, there is no notion called setup pipeline.
   }
 
+  @Override
   public void destroyPipeline() {
     // For stand alone pipeline, there is no notion called destroy pipeline.
   }

hadoop-hdds/client/src/main/java/org/apache/hadoop/hdds/scm/XceiverClientManager.java

@@ -170,6 +170,7 @@ public XceiverClientSpi call() throws Exception {
   /**
    * Close and remove all the cached clients.
    */
+  @Override
   public void close() {
     //closing is done through RemovalListener
     clientCache.invalidateAll();

hadoop-hdds/client/src/main/java/org/apache/hadoop/hdds/scm/XceiverClientRatis.java

@@ -100,6 +100,7 @@ private XceiverClientRatis(Pipeline pipeline, RpcType rpcType,
   /**
    * {@inheritDoc}
    */
+  @Override
   public void createPipeline() throws IOException {
     final RaftGroup group = RatisHelper.newRaftGroup(pipeline);
     LOG.debug("creating pipeline:{} with {}", pipeline.getId(), group);
@@ -110,6 +111,7 @@ public void createPipeline() throws IOException {
   /**
    * {@inheritDoc}
    */
+  @Override
   public void destroyPipeline() throws IOException {
     final RaftGroup group = RatisHelper.newRaftGroup(pipeline);
     LOG.debug("destroying pipeline:{} with {}", pipeline.getId(), group);

hadoop-hdds/client/src/main/java/org/apache/hadoop/hdds/scm/storage/ChunkInputStream.java

@@ -83,7 +83,7 @@ public ChunkInputStream(
   }
 
   private void initializeChunkOffset() {
-    int tempOffset = 0;
+    long tempOffset = 0;
     for (int i = 0; i < chunks.size(); i++) {
       chunkOffset[i] = tempOffset;
       tempOffset += chunks.get(i).getLen();

hadoop-hdds/common/src/main/java/org/apache/hadoop/hdds/scm/pipeline/Pipeline.java

@@ -196,6 +196,17 @@ public static Builder newBuilder(Pipeline pipeline) {
     return new Builder(pipeline);
   }
 
+  @Override
+  public String toString() {
+    return "Pipeline{" +
+        "id=" + id +
+        ", type=" + type +
+        ", factor=" + factor +
+        ", state=" + state +
+        ", nodeStatus=" + nodeStatus +
+        '}';
+  }
+
   /**
    * Builder class for Pipeline.
    */

hadoop-hdds/common/src/main/java/org/apache/hadoop/ozone/common/StorageInfo.java

@@ -68,7 +68,6 @@ public StorageInfo(NodeType type, String cid, long cT)
       throws IOException {
     Preconditions.checkNotNull(type);
     Preconditions.checkNotNull(cid);
-    Preconditions.checkNotNull(cT);
     properties.setProperty(NODE_TYPE, type.name());
     properties.setProperty(CLUSTER_ID, cid);
     properties.setProperty(CREATION_TIME, String.valueOf(cT));

hadoop-hdds/common/src/main/java/org/apache/hadoop/utils/db/RDBStore.java

@@ -24,11 +24,9 @@
 import org.apache.hadoop.hdfs.DFSUtil;
 import org.apache.hadoop.metrics2.util.MBeans;
 import org.apache.hadoop.utils.RocksDBStoreMBean;
-import org.apache.ratis.thirdparty.com.google.common.annotations.
+import org.apache.ratis.thirdparty.com.google.common.annotations.VisibleForTesting;
-    VisibleForTesting;
 import org.rocksdb.ColumnFamilyDescriptor;
 import org.rocksdb.ColumnFamilyHandle;
-
 import org.rocksdb.DBOptions;
 import org.rocksdb.RocksDB;
 import org.rocksdb.RocksDBException;
@@ -192,7 +190,6 @@ public void move(byte[] key, Table source, Table dest) throws IOException {
     }
   }
 
-
   @Override
   public void move(byte[] key, byte[] value, Table source,
       Table dest) throws IOException {

hadoop-hdds/common/src/test/java/org/apache/hadoop/ozone/audit/DummyAction.java

@@ -37,7 +37,7 @@ public enum DummyAction implements AuditAction {
   SET_OWNER("SET_OWNER"),
   SET_QUOTA("SET_QUOTA");
 
-  private String action;
+  private final String action;
 
   DummyAction(String action) {
     this.action = action;

hadoop-hdds/common/src/test/java/org/apache/hadoop/ozone/lease/TestLeaseManager.java

@@ -41,7 +41,7 @@ public class TestLeaseManager {
   /**
    * Dummy resource on which leases can be acquired.
    */
-  private final class DummyResource {
+  private static final class DummyResource {
 
     private final String name;
 
@@ -61,6 +61,21 @@ public boolean equals(Object obj) {
       }
       return false;
     }
+
+    /**
+     * Adding to String method to fix the ErrorProne warning that this method
+     * is later used in String functions, which would print out (e.g.
+     * `org.apache.hadoop.ozone.lease.TestLeaseManager.DummyResource@
+     * 4488aabb`) instead of useful information.
+     *
+     * @return Name of the Dummy object.
+     */
+    @Override
+    public String toString() {
+      return "DummyResource{" +
+          "name='" + name + '\'' +
+          '}';
+    }
   }
 
   @Test

hadoop-hdds/common/src/test/java/org/apache/hadoop/utils/TestHddsIdFactory.java

@@ -55,7 +55,7 @@ public void testGetLongId() throws Exception {
     List<Future<Integer>> result = executor.invokeAll(tasks);
     assertEquals(IDS_PER_THREAD * NUM_OF_THREADS, ID_SET.size());
     for (Future<Integer> r : result) {
-      assertEquals(r.get().intValue(), IDS_PER_THREAD);
+      assertEquals(IDS_PER_THREAD, r.get().intValue());
     }
   }
 

hadoop-hdds/common/src/test/java/org/apache/hadoop/utils/TestMetadataStore.java

@@ -1,24 +1,21 @@
 /**
- * Licensed to the Apache Software Foundation (ASF) under one
+ * Licensed to the Apache Software Foundation (ASF) under one or more
- * or more contributor license agreements.  See the NOTICE file
+ * contributor license agreements.  See the NOTICE file distributed with this
- * distributed with this work for additional information
+ * work for additional information regarding copyright ownership.  The ASF
- * regarding copyright ownership.  The ASF licenses this file
+ * licenses this file to you under the Apache License, Version 2.0 (the
- * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the License.
- * "License"); you may not use this file except in compliance
+ * You may obtain a copy of the License at
- * with the License.  You may obtain a copy of the License at
  * <p>
  * http://www.apache.org/licenses/LICENSE-2.0
  * <p>
  * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
- * See the License for the specific language governing permissions and
+ * License for the specific language governing permissions and limitations under
- * limitations under the License.
+ * the License.
  */
 package org.apache.hadoop.utils;
 
-import static org.apache.hadoop.test.PlatformAssumptions.assumeNotWindows;
-
 import com.google.common.collect.Lists;
 import org.apache.commons.io.FileUtils;
 import org.apache.commons.lang3.tuple.ImmutablePair;
@@ -28,9 +25,9 @@
 import org.apache.hadoop.hdfs.DFSUtilClient;
 import org.apache.hadoop.ozone.OzoneConfigKeys;
 import org.apache.hadoop.test.GenericTestUtils;
-import org.apache.hadoop.utils.MetadataStore.KeyValue;
 import org.apache.hadoop.utils.MetadataKeyFilters.KeyPrefixFilter;
 import org.apache.hadoop.utils.MetadataKeyFilters.MetadataKeyFilter;
+import org.apache.hadoop.utils.MetadataStore.KeyValue;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Rule;
@@ -50,14 +47,14 @@
 import java.util.Map;
 import java.util.NoSuchElementException;
 import java.util.UUID;
-
 import java.util.concurrent.atomic.AtomicInteger;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
+import static org.apache.hadoop.test.PlatformAssumptions.assumeNotWindows;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
-
 import static org.junit.runners.Parameterized.Parameters;
 
 /**
@@ -66,27 +63,24 @@
 @RunWith(Parameterized.class)
 public class TestMetadataStore {
 
+  private final static int MAX_GETRANGE_LENGTH = 100;
   private final String storeImpl;
-
+  @Rule
+  public ExpectedException expectedException = ExpectedException.none();
+  private MetadataStore store;
+  private File testDir;
   public TestMetadataStore(String metadataImpl) {
     this.storeImpl = metadataImpl;
   }
 
   @Parameters
   public static Collection<Object[]> data() {
-    return Arrays.asList(new Object[][] {
+    return Arrays.asList(new Object[][]{
         {OzoneConfigKeys.OZONE_METADATA_STORE_IMPL_LEVELDB},
         {OzoneConfigKeys.OZONE_METADATA_STORE_IMPL_ROCKSDB}
     });
   }
 
-  private MetadataStore store;
-  private File testDir;
-  private final static int MAX_GETRANGE_LENGTH = 100;
-
-  @Rule
-  public ExpectedException expectedException = ExpectedException.none();
-
   @Before
   public void init() throws IOException {
     if (OzoneConfigKeys.OZONE_METADATA_STORE_IMPL_ROCKSDB.equals(storeImpl)) {
@@ -109,7 +103,7 @@ public void init() throws IOException {
     // Add 20 entries.
     // {a0 : a-value0} to {a9 : a-value9}
     // {b0 : b-value0} to {b9 : b-value9}
-    for (int i=0; i<10; i++) {
+    for (int i = 0; i < 10; i++) {
       store.put(getBytes("a" + i), getBytes("a-value" + i));
       store.put(getBytes("b" + i), getBytes("b-value" + i));
     }
@@ -178,7 +172,7 @@ public void testMetaStoreConfigDifferentFromType() throws IOException {
     GenericTestUtils.setLogLevel(MetadataStoreBuilder.LOG, Level.DEBUG);
     GenericTestUtils.LogCapturer logCapturer =
         GenericTestUtils.LogCapturer.captureLogs(MetadataStoreBuilder.LOG);
-    if(storeImpl.equals(OzoneConfigKeys.OZONE_METADATA_STORE_IMPL_LEVELDB)) {
+    if (storeImpl.equals(OzoneConfigKeys.OZONE_METADATA_STORE_IMPL_LEVELDB)) {
       dbType = "RocksDB";
     } else {
       dbType = "LevelDB";
@@ -241,7 +235,7 @@ private String getString(byte[] bytes) {
 
   @Test
   public void testGetDelete() throws IOException {
-    for (int i=0; i<10; i++) {
+    for (int i = 0; i < 10; i++) {
       byte[] va = store.get(getBytes("a" + i));
       assertEquals("a-value" + i, getString(va));
 
@@ -273,7 +267,7 @@ private String getExpectedValue(String key) {
       return null;
     }
     char[] arr = key.toCharArray();
-    return new StringBuffer().append(arr[0]).append("-value")
+    return new StringBuilder().append(arr[0]).append("-value")
         .append(arr[arr.length - 1]).toString();
   }
 
@@ -332,8 +326,8 @@ public void testIterateKeys() throws IOException {
     });
 
     assertFalse(result.isEmpty());
-    for (int i=0; i<result.size(); i++) {
+    for (int i = 0; i < result.size(); i++) {
-      assertEquals("b-value" + (i+1), result.get(i));
+      assertEquals("b-value" + (i + 1), result.get(i));
     }
 
     // iterate from a non exist key
@@ -388,7 +382,7 @@ public void testGetRangeKVs() throws IOException {
     result = store.getRangeKVs(null, 100, filter1);
     assertEquals(10, result.size());
     assertTrue(result.stream().allMatch(entry ->
-        new String(entry.getKey()).startsWith("b")
+        new String(entry.getKey(), UTF_8).startsWith("b")
     ));
     assertEquals(20, filter1.getKeysScannedNum());
     assertEquals(10, filter1.getKeysHintedNum());
@@ -416,7 +410,7 @@ public void testGetRangeKVs() throws IOException {
     assertEquals("b-value2", getString(result.get(0).getValue()));
 
     // If filter is null, no effect.
-    result = store.getRangeKVs(null, 1, null);
+    result = store.getRangeKVs(null, 1, (MetadataKeyFilter[]) null);
     assertEquals(1, result.size());
     assertEquals("a0", getString(result.get(0).getKey()));
   }
@@ -461,7 +455,7 @@ public void testInvalidStartKey() throws IOException {
     // If startKey is invalid, the returned list should be empty.
     List<Map.Entry<byte[], byte[]>> kvs =
         store.getRangeKVs(getBytes("unknownKey"), MAX_GETRANGE_LENGTH);
-    assertEquals(kvs.size(), 0);
+    assertEquals(0, kvs.size());
   }
 
   @Test
@@ -504,7 +498,7 @@ public void testBatchWrite() throws IOException {
         .build();
 
     List<String> expectedResult = Lists.newArrayList();
-    for (int i = 0; i<10; i++) {
+    for (int i = 0; i < 10; i++) {
       dbStore.put(getBytes("batch-" + i), getBytes("batch-value-" + i));
       expectedResult.add("batch-" + i);
     }
@@ -541,33 +535,33 @@ public void testKeyPrefixFilter() throws IOException {
       new KeyPrefixFilter().addFilter("b0", true).addFilter("b");
     } catch (IllegalArgumentException e) {
       exception = e;
-    }
       assertTrue(exception.getMessage().contains("KeyPrefix: b already " +
           "rejected"));
+    }
 
     try {
       new KeyPrefixFilter().addFilter("b0").addFilter("b", true);
     } catch (IllegalArgumentException e) {
       exception = e;
-    }
       assertTrue(exception.getMessage().contains("KeyPrefix: b already " +
           "accepted"));
+    }
 
     try {
       new KeyPrefixFilter().addFilter("b", true).addFilter("b0");
     } catch (IllegalArgumentException e) {
       exception = e;
-    }
       assertTrue(exception.getMessage().contains("KeyPrefix: b0 already " +
           "rejected"));
+    }
 
     try {
       new KeyPrefixFilter().addFilter("b").addFilter("b0", true);
     } catch (IllegalArgumentException e) {
       exception = e;
-    }
       assertTrue(exception.getMessage().contains("KeyPrefix: b0 already " +
           "accepted"));
+    }
 
     MetadataKeyFilter filter1 = new KeyPrefixFilter(true)
         .addFilter("a0")
@@ -575,9 +569,10 @@ public void testKeyPrefixFilter() throws IOException {
         .addFilter("b", true);
     result = store.getRangeKVs(null, 100, filter1);
     assertEquals(2, result.size());
-    assertTrue(result.stream().anyMatch(entry -> new String(entry.getKey())
+    assertTrue(result.stream().anyMatch(entry -> new String(entry.getKey(),
+        UTF_8)
         .startsWith("a0")) && result.stream().anyMatch(entry -> new String(
-            entry.getKey()).startsWith("a1")));
+        entry.getKey(), UTF_8).startsWith("a1")));
 
     filter1 = new KeyPrefixFilter(true).addFilter("b", true);
     result = store.getRangeKVs(null, 100, filter1);
@@ -586,7 +581,8 @@ public void testKeyPrefixFilter() throws IOException {
     filter1 = new KeyPrefixFilter().addFilter("b", true);
     result = store.getRangeKVs(null, 100, filter1);
     assertEquals(10, result.size());
-    assertTrue(result.stream().allMatch(entry -> new String(entry.getKey())
+    assertTrue(result.stream().allMatch(entry -> new String(entry.getKey(),
+        UTF_8)
         .startsWith("a")));
   }
 }

hadoop-hdds/common/src/test/java/org/apache/hadoop/utils/TestRocksDBStoreMBean.java

@@ -29,12 +29,14 @@
 import java.io.File;
 import java.lang.management.ManagementFactory;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
+
 /**
  * Test the JMX interface for the rocksdb metastore implementation.
  */
 public class TestRocksDBStoreMBean {
   
-  Configuration conf;
+  private Configuration conf;
   
   @Before
   public void init() throws Exception {
@@ -57,7 +59,7 @@ public void testJmxBeans() throws Exception {
             .setCreateIfMissing(true).setDbFile(testDir).build();
 
     for (int i = 0; i < 10; i++) {
-      metadataStore.put("key".getBytes(), "value".getBytes());
+      metadataStore.put("key".getBytes(UTF_8), "value".getBytes(UTF_8));
     }
 
     MBeanServer platformMBeanServer =

hadoop-hdds/common/src/test/java/org/apache/hadoop/utils/db/TestDBStoreBuilder.java

@@ -131,7 +131,7 @@ public void builderWithDataWrites() throws Exception {
             RandomStringUtils.random(9).getBytes(StandardCharsets.UTF_8);
         firstTable.put(key, value);
         byte[] temp = firstTable.get(key);
-        Arrays.equals(value, temp);
+        Assert.assertTrue(Arrays.equals(value, temp));
       }
 
       try (Table secondTable = dbStore.getTable("Second")) {
@@ -161,7 +161,7 @@ public void builderWithDiskProfileWrites() throws Exception {
             RandomStringUtils.random(9).getBytes(StandardCharsets.UTF_8);
         firstTable.put(key, value);
         byte[] temp = firstTable.get(key);
-        Arrays.equals(value, temp);
+        Assert.assertTrue(Arrays.equals(value, temp));
       }
 
       try (Table secondTable = dbStore.getTable("Second")) {

hadoop-hdds/common/src/test/java/org/apache/hadoop/utils/db/TestRDBTableStore.java

@@ -35,9 +35,9 @@
 import org.rocksdb.WriteBatch;
 
 import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashSet;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Set;
 
@@ -112,8 +112,8 @@ public void putGetAndEmpty() throws Exception {
 
   @Test
   public void delete() throws Exception {
-    List<byte[]> deletedKeys = new LinkedList<>();
+    List<byte[]> deletedKeys = new ArrayList<>();
-    List<byte[]> validKeys = new LinkedList<>();
+    List<byte[]> validKeys = new ArrayList<>();
     byte[] value =
         RandomStringUtils.random(10).getBytes(StandardCharsets.UTF_8);
     for (int x = 0; x < 100; x++) {

hadoop-hdds/common/src/test/java/org/apache/hadoop/utils/package-info.java

@@ -0,0 +1,22 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * <p>
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ */
+/**
+ * DB test Utils.
+ */
+package org.apache.hadoop.utils;

hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/keyvalue/impl/BlockManagerImpl.java

@@ -141,8 +141,8 @@ public BlockData getBlock(Container container, BlockID blockID)
     long bcsId = blockID.getBlockCommitSequenceId();
     Preconditions.checkNotNull(blockID,
         "BlockID cannot be null in GetBlock request");
-    Preconditions.checkNotNull(blockID.getContainerID(),
+    Preconditions.checkNotNull(container,
-        "Container name cannot be null");
+        "Container cannot be null");
 
     KeyValueContainerData containerData = (KeyValueContainerData) container
         .getContainerData();

hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/replication/GrpcReplicationClient.java

@@ -114,7 +114,7 @@ public StreamDownloader(long containerId, CompletableFuture<Path> response,
       this.containerId = containerId;
       this.outputPath = outputPath;
       try {
-        outputPath = Preconditions.checkNotNull(outputPath);
+        Preconditions.checkNotNull(outputPath, "Output path cannot be null");
         Path parentPath = Preconditions.checkNotNull(outputPath.getParent());
         Files.createDirectories(parentPath);
         stream =

hadoop-hdds/container-service/src/test/java/org/apache/hadoop/ozone/container/common/ScmTestMock.java

@@ -71,8 +71,8 @@ public ScmTestMock() {
       new HashMap<>();
   private Map<DatanodeDetails, NodeReportProto> nodeReports = new HashMap<>();
   private AtomicInteger commandStatusReport = new AtomicInteger(0);
-  private List<CommandStatus> cmdStatusList = new LinkedList<>();
+  private List<CommandStatus> cmdStatusList = new ArrayList<>();
-  private List<SCMCommandProto> scmCommandRequests = new LinkedList<>();
+  private List<SCMCommandProto> scmCommandRequests = new ArrayList<>();
   /**
    * Returns the number of heartbeats made to this class.
    *

hadoop-hdds/container-service/src/test/java/org/apache/hadoop/ozone/container/common/TestDatanodeStateMachine.java

@@ -50,7 +50,7 @@
 import java.io.IOException;
 import java.net.InetSocketAddress;
 import java.nio.file.Paths;
-import java.util.LinkedList;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.UUID;
@@ -86,9 +86,9 @@ public void setUp() throws Exception {
     conf.setTimeDuration(OZONE_SCM_HEARTBEAT_RPC_TIMEOUT, 500,
         TimeUnit.MILLISECONDS);
     conf.setBoolean(OzoneConfigKeys.DFS_CONTAINER_RATIS_IPC_RANDOM_PORT, true);
-    serverAddresses = new LinkedList<>();
+    serverAddresses = new ArrayList<>();
-    scmServers = new LinkedList<>();
+    scmServers = new ArrayList<>();
-    mockServers = new LinkedList<>();
+    mockServers = new ArrayList<>();
     for (int x = 0; x < scmServerCount; x++) {
       int port = SCMTestUtils.getReuseableAddress().getPort();
       String address = "127.0.0.1";
@@ -361,8 +361,8 @@ public void testDatanodeStateMachineWithIdWriteFail() throws Exception {
   @Test
   public void testDatanodeStateMachineWithInvalidConfiguration()
       throws Exception {
-    LinkedList<Map.Entry<String, String>> confList =
+    List<Map.Entry<String, String>> confList =
-        new LinkedList<Map.Entry<String, String>>();
+        new ArrayList<>();
     confList.add(Maps.immutableEntry(ScmConfigKeys.OZONE_SCM_NAMES, ""));
 
     // Invalid ozone.scm.names

hadoop-hdds/container-service/src/test/java/org/apache/hadoop/ozone/container/common/impl/TestHddsDispatcher.java

@@ -49,6 +49,7 @@
 import java.io.IOException;
 import java.util.UUID;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.apache.hadoop.hdds.scm.ScmConfigKeys.HDDS_DATANODE_DIR_KEY;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
@@ -160,7 +161,7 @@ private ContainerCommandRequestProto getWriteChunkRequest(
       String datanodeId, Long containerId, Long localId) {
 
     ByteString data = ByteString.copyFrom(
-        UUID.randomUUID().toString().getBytes());
+        UUID.randomUUID().toString().getBytes(UTF_8));
     ContainerProtos.ChunkInfo chunk = ContainerProtos.ChunkInfo
         .newBuilder()
         .setChunkName(

hadoop-hdds/container-service/src/test/java/org/apache/hadoop/ozone/container/common/report/TestReportPublisher.java

@@ -61,7 +61,7 @@ public static void setup() {
   /**
    * Dummy report publisher for testing.
    */
-  private class DummyReportPublisher extends ReportPublisher {
+  private static class DummyReportPublisher extends ReportPublisher {
 
     private final long frequency;
     private int getReportCount = 0;

hadoop-hdds/container-service/src/test/java/org/apache/hadoop/ozone/container/common/volume/TestHddsVolume.java

@@ -1,19 +1,18 @@
 /**
- * Licensed to the Apache Software Foundation (ASF) under one
+ * Licensed to the Apache Software Foundation (ASF) under one or more
- * or more contributor license agreements.  See the NOTICE file
+ * contributor license agreements.  See the NOTICE file distributed with this
- * distributed with this work for additional information
+ * work for additional information regarding copyright ownership.  The ASF
- * regarding copyright ownership.  The ASF licenses this file
+ * licenses this file to you under the Apache License, Version 2.0 (the
- * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the License.
- * "License"); you may not use this file except in compliance
+ * You may obtain a copy of the License at
- * with the License.  You may obtain a copy of the License at
+ * <p>
- *
  * http://www.apache.org/licenses/LICENSE-2.0
- *
+ * <p>
  * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
- * See the License for the specific language governing permissions and
+ * License for the specific language governing permissions and limitations under
- * limitations under the License.
+ * the License.
  */
 
 package org.apache.hadoop.ozone.container.common.volume;
@@ -23,7 +22,6 @@
 import org.apache.hadoop.fs.StorageType;
 import org.apache.hadoop.ozone.container.common.helpers.DatanodeVersionFile;
 import org.apache.hadoop.ozone.container.common.utils.HddsVolumeUtil;
-import static org.junit.Assert.*;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
@@ -35,19 +33,22 @@
 import java.util.Properties;
 import java.util.UUID;
 
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
 /**
  * Unit tests for {@link HddsVolume}.
  */
 public class TestHddsVolume {
 
-  @Rule
-  public TemporaryFolder folder = new TemporaryFolder();
-
   private static final String DATANODE_UUID = UUID.randomUUID().toString();
   private static final String CLUSTER_ID = UUID.randomUUID().toString();
   private static final Configuration CONF = new Configuration();
   private static final String DU_CACHE_FILE = "scmUsed";
-
+  @Rule
+  public TemporaryFolder folder = new TemporaryFolder();
   private File rootDir;
   private HddsVolume volume;
   private File versionFile;
@@ -69,9 +70,9 @@ public void testHddsVolumeInitialization() throws Exception {
     // clusterID is not specified and the version file should not be written
     // to disk.
     assertTrue(volume.getClusterID() == null);
-    assertEquals(volume.getStorageType(), StorageType.DEFAULT);
+    assertEquals(StorageType.DEFAULT, volume.getStorageType());
-    assertEquals(volume.getStorageState(),
+    assertEquals(HddsVolume.VolumeState.NOT_FORMATTED,
-        HddsVolume.VolumeState.NOT_FORMATTED);
+        volume.getStorageState());
     assertFalse("Version file should not be created when clusterID is not " +
         "known.", versionFile.exists());
 
@@ -84,7 +85,7 @@ public void testHddsVolumeInitialization() throws Exception {
     assertTrue("Volume format should create Version file",
         versionFile.exists());
     assertEquals(volume.getClusterID(), CLUSTER_ID);
-    assertEquals(volume.getStorageState(), HddsVolume.VolumeState.NORMAL);
+    assertEquals(HddsVolume.VolumeState.NORMAL, volume.getStorageState());
   }
 
   @Test
@@ -111,7 +112,7 @@ public void testReadPropertiesFromVersionFile() throws Exception {
   }
 
   @Test
-  public void testShutdown() throws Exception{
+  public void testShutdown() throws Exception {
     // Return dummy value > 0 for scmUsage so that scm cache file is written
     // during shutdown.
     GetSpaceUsed scmUsageMock = Mockito.mock(GetSpaceUsed.class);
@@ -125,8 +126,7 @@ public void testShutdown() throws Exception{
     volume.shutdown();
 
     // Volume state should be "NON_EXISTENT" when volume is shutdown.
-    assertEquals(volume.getStorageState(),
+    assertEquals(HddsVolume.VolumeState.NON_EXISTENT, volume.getStorageState());
-        HddsVolume.VolumeState.NON_EXISTENT);
 
     // Volume should save scmUsed cache file once volume is shutdown
     File scmUsedFile = new File(folder.getRoot(), DU_CACHE_FILE);
@@ -139,7 +139,7 @@ public void testShutdown() throws Exception{
       // as usage thread is shutdown.
       volume.getAvailable();
       fail("HddsVolume#shutdown test failed");
-    } catch (Exception ex){
+    } catch (Exception ex) {
       assertTrue(ex instanceof IOException);
       assertTrue(ex.getMessage().contains(
           "Volume Usage thread is not running."));

hadoop-hdds/container-service/src/test/java/org/apache/hadoop/ozone/container/common/volume/TestVolumeSet.java

@@ -22,7 +22,6 @@
 import org.apache.commons.io.FileUtils;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.fs.FileUtil;
-import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hdds.conf.OzoneConfiguration;
 import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.MiniDFSCluster;
@@ -69,7 +68,7 @@ private void initializeVolumeSet() throws Exception {
   }
 
   @Rule
-  public Timeout testTimeout = new Timeout(300_000);
+  public Timeout testTimeout = new Timeout(300000);
 
   @Before
   public void setup() throws Exception {
@@ -153,8 +152,7 @@ public void testFailVolume() throws Exception {
     assertTrue(volumeSet.getFailedVolumesList().get(0).isFailed());
 
     // Failed volume should not exist in VolumeMap
-    Path volume1Path = new Path(volume1);
+    assertFalse(volumeSet.getVolumeMap().containsKey(volume1));
-    assertFalse(volumeSet.getVolumeMap().containsKey(volume1Path));
   }
 
   @Test

hadoop-hdds/container-service/src/test/java/org/apache/hadoop/ozone/container/common/volume/package-info.java

@@ -0,0 +1,22 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * <p>
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ */
+/**
+ * Tests for Container Volumes.
+ */
+package org.apache.hadoop.ozone.container.common.volume;

hadoop-hdds/container-service/src/test/java/org/apache/hadoop/ozone/container/keyvalue/TestBlockManagerImpl.java

@@ -25,10 +25,9 @@
 import org.apache.hadoop.hdds.scm.container.common.helpers.StorageContainerException;
 import org.apache.hadoop.ozone.container.common.helpers.BlockData;
 import org.apache.hadoop.ozone.container.common.helpers.ChunkInfo;
-import org.apache.hadoop.ozone.container.common.volume
-    .RoundRobinVolumeChoosingPolicy;
-import org.apache.hadoop.ozone.container.common.volume.VolumeSet;
 import org.apache.hadoop.ozone.container.common.volume.HddsVolume;
+import org.apache.hadoop.ozone.container.common.volume.RoundRobinVolumeChoosingPolicy;
+import org.apache.hadoop.ozone.container.common.volume.VolumeSet;
 import org.apache.hadoop.ozone.container.keyvalue.impl.BlockManagerImpl;
 import org.apache.hadoop.test.GenericTestUtils;
 import org.junit.Before;
@@ -37,12 +36,14 @@
 import org.junit.rules.TemporaryFolder;
 import org.mockito.Mockito;
 
-import java.io.IOException;
+import java.util.ArrayList;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.UUID;
 
-import static org.junit.Assert.*;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 import static org.mockito.ArgumentMatchers.anyList;
 import static org.mockito.ArgumentMatchers.anyLong;
 import static org.mockito.Mockito.mock;
@@ -52,6 +53,8 @@
  */
 public class TestBlockManagerImpl {
 
+  @Rule
+  public TemporaryFolder folder = new TemporaryFolder();
   private OzoneConfiguration config;
   private String scmId = UUID.randomUUID().toString();
   private VolumeSet volumeSet;
@@ -62,10 +65,6 @@ public class TestBlockManagerImpl {
   private BlockManagerImpl blockManager;
   private BlockID blockID;
 
-  @Rule
-  public TemporaryFolder folder = new TemporaryFolder();
-
-
   @Before
   public void setUp() throws Exception {
     config = new OzoneConfiguration();
@@ -93,7 +92,7 @@ public void setUp() throws Exception {
     blockData = new BlockData(blockID);
     blockData.addMetadata("VOLUME", "ozone");
     blockData.addMetadata("OWNER", "hdfs");
-    List<ContainerProtos.ChunkInfo> chunkList = new LinkedList<>();
+    List<ContainerProtos.ChunkInfo> chunkList = new ArrayList<>();
     ChunkInfo info = new ChunkInfo(String.format("%d.data.%d", blockID
         .getLocalID(), 0), 0, 1024);
     chunkList.add(info.getProtoBufMessage());
@@ -124,10 +123,8 @@ public void testPutAndGetBlock() throws Exception {
 
   }
 
-
   @Test
   public void testDeleteBlock() throws Exception {
-    try {
     assertEquals(0,
         keyValueContainer.getContainerData().getKeyCount());
     //Put Block
@@ -145,14 +142,10 @@ public void testDeleteBlock() throws Exception {
       GenericTestUtils.assertExceptionContains(
           "Unable to find the block", ex);
     }
-    } catch (IOException ex) {
-      fail("testDeleteBlock failed");
-    }
   }
 
   @Test
   public void testListBlock() throws Exception {
-    try {
     blockManager.putBlock(keyValueContainer, blockData);
     List<BlockData> listBlockData = blockManager.listBlock(
         keyValueContainer, 1, 10);
@@ -164,7 +157,7 @@ public void testListBlock() throws Exception {
       blockData = new BlockData(blockID);
       blockData.addMetadata("VOLUME", "ozone");
       blockData.addMetadata("OWNER", "hdfs");
-        List<ContainerProtos.ChunkInfo> chunkList = new LinkedList<>();
+      List<ContainerProtos.ChunkInfo> chunkList = new ArrayList<>();
       ChunkInfo info = new ChunkInfo(String.format("%d.data.%d", blockID
           .getLocalID(), 0), 0, 1024);
       chunkList.add(info.getProtoBufMessage());
@@ -176,15 +169,10 @@ public void testListBlock() throws Exception {
         keyValueContainer, 1, 10);
     assertNotNull(listBlockData);
     assertTrue(listBlockData.size() == 10);
-
-    } catch (IOException ex) {
-      fail("testListBlock failed");
-    }
   }
 
   @Test
   public void testGetNoSuchBlock() throws Exception {
-    try {
     assertEquals(0,
         keyValueContainer.getContainerData().getKeyCount());
     //Put Block
@@ -204,8 +192,5 @@ public void testGetNoSuchBlock() throws Exception {
           "Unable to find the block", ex);
       assertEquals(ContainerProtos.Result.NO_SUCH_BLOCK, ex.getResult());
     }
-    } catch (IOException ex) {
-      fail("testGetNoSuchBlock failed");
-    }
   }
 }

hadoop-hdds/container-service/src/test/java/org/apache/hadoop/ozone/container/keyvalue/TestChunkManagerImpl.java

@@ -43,6 +43,7 @@
 import java.util.Arrays;
 import java.util.UUID;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.junit.Assert.*;
 import static org.mockito.ArgumentMatchers.anyList;
 import static org.mockito.ArgumentMatchers.anyLong;
@@ -88,7 +89,7 @@ public void setUp() throws Exception {
 
     keyValueContainer.create(volumeSet, volumeChoosingPolicy, scmId);
 
-    data = "testing write chunks".getBytes();
+    data = "testing write chunks".getBytes(UTF_8);
     // Creating BlockData
     blockID = new BlockID(1L, 1L);
     chunkInfo = new ChunkInfo(String.format("%d.data.%d", blockID

hadoop-hdds/container-service/src/test/java/org/apache/hadoop/ozone/container/keyvalue/TestKeyValueBlockIterator.java

@@ -42,9 +42,9 @@
 import org.junit.runners.Parameterized;
 
 import java.io.File;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.NoSuchElementException;
 import java.util.UUID;
@@ -252,7 +252,7 @@ private void createContainerWithBlocks(long containerId, int
         .randomUUID().toString());
     MetadataStore metadataStore = BlockUtils.getDB(containerData, conf);
 
-    List<ContainerProtos.ChunkInfo> chunkList = new LinkedList<>();
+    List<ContainerProtos.ChunkInfo> chunkList = new ArrayList<>();
     ChunkInfo info = new ChunkInfo("chunkfile", 0, 1024);
     chunkList.add(info.getProtoBufMessage());
 

hadoop-hdds/container-service/src/test/java/org/apache/hadoop/ozone/container/keyvalue/TestKeyValueContainer.java

@@ -51,12 +51,13 @@
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.List;
-import java.util.LinkedList;
 import java.util.UUID;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.apache.ratis.util.Preconditions.assertTrue;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
@@ -135,7 +136,7 @@ private void addBlocks(int count) throws Exception {
       BlockData blockData = new BlockData(blockID);
       blockData.addMetadata("VOLUME", "ozone");
       blockData.addMetadata("OWNER", "hdfs");
-      List<ContainerProtos.ChunkInfo> chunkList = new LinkedList<>();
+      List<ContainerProtos.ChunkInfo> chunkList = new ArrayList<>();
       ChunkInfo info = new ChunkInfo(String.format("%d.data.%d", blockID
           .getLocalID(), 0), 0, 1024);
       chunkList.add(info.getProtoBufMessage());
@@ -163,8 +164,6 @@ public void testCreateContainer() throws Exception {
     // Check whether containerMetaDataPath and chunksPath exists or not.
     assertTrue(containerMetaDataPath != null);
     assertTrue(chunksPath != null);
-    File containerMetaDataLoc = new File(containerMetaDataPath);
-
     //Check whether container file and container db file exists or not.
     assertTrue(keyValueContainer.getContainerFile().exists(),
         ".Container File does not exist");
@@ -190,7 +189,7 @@ public void testContainerImportExport() throws Exception {
     //write one few keys to check the key count after import
     MetadataStore metadataStore = BlockUtils.getDB(keyValueContainerData, conf);
     for (int i = 0; i < numberOfKeysToWrite; i++) {
-      metadataStore.put(("test" + i).getBytes(), "test".getBytes());
+      metadataStore.put(("test" + i).getBytes(UTF_8), "test".getBytes(UTF_8));
     }
     metadataStore.close();
 
@@ -247,7 +246,7 @@ public void testContainerImportExport() throws Exception {
         container.importContainerData(fis, packer);
       }
       fail("Container is imported twice. Previous files are overwritten");
-    } catch (Exception ex) {
+    } catch (IOException ex) {
       //all good
     }
 

hadoop-hdds/container-service/src/test/java/org/apache/hadoop/ozone/container/keyvalue/TestKeyValueHandler.java

@@ -226,9 +226,10 @@ public void testVolumeSetInKeyValueHandler() throws Exception{
       VolumeSet volumeSet = new VolumeSet(UUID.randomUUID().toString(), conf);
       KeyValueHandler keyValueHandler = new KeyValueHandler(conf, cset,
           volumeSet, metrics);
-      assertEquals(keyValueHandler.getVolumeChoosingPolicyForTesting()
+      assertEquals("org.apache.hadoop.ozone.container.common" +
-          .getClass().getName(), "org.apache.hadoop.ozone.container.common" +
+          ".volume.RoundRobinVolumeChoosingPolicy",
-          ".volume.RoundRobinVolumeChoosingPolicy");
+          keyValueHandler.getVolumeChoosingPolicyForTesting()
+              .getClass().getName());
 
       //Set a class which is not of sub class of VolumeChoosingPolicy
       conf.set(HDDS_DATANODE_VOLUME_CHOOSING_POLICY,

hadoop-hdds/container-service/src/test/java/org/apache/hadoop/ozone/container/keyvalue/TestTarContainerPacker.java

@@ -23,7 +23,6 @@
 import java.io.FileWriter;
 import java.io.IOException;
 import java.nio.charset.Charset;
-import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
@@ -45,6 +44,8 @@
 import org.junit.BeforeClass;
 import org.junit.Test;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
+
 /**
  * Test the tar/untar for a given container.
  */
@@ -161,7 +162,7 @@ public void pack() throws IOException, CompressorException {
     //read the container descriptor only
     try (FileInputStream input = new FileInputStream(targetFile.toFile())) {
       String containerYaml = new String(packer.unpackContainerDescriptor(input),
-          Charset.forName(StandardCharsets.UTF_8.name()));
+          Charset.forName(UTF_8.name()));
       Assert.assertEquals(TEST_DESCRIPTOR_FILE_CONTENT, containerYaml);
     }
 
@@ -177,7 +178,7 @@ public void pack() throws IOException, CompressorException {
     try (FileInputStream input = new FileInputStream(targetFile.toFile())) {
       descriptor =
           new String(packer.unpackContainerData(destinationContainer, input),
-              Charset.forName(StandardCharsets.UTF_8.name()));
+              Charset.forName(UTF_8.name()));
     }
 
     assertExampleMetadataDbIsGood(
@@ -204,7 +205,7 @@ private void assertExampleMetadataDbIsGood(Path dbPath)
 
     try (FileInputStream testFile = new FileInputStream(dbFile.toFile())) {
       List<String> strings = IOUtils
-          .readLines(testFile, Charset.forName(StandardCharsets.UTF_8.name()));
+          .readLines(testFile, Charset.forName(UTF_8.name()));
       Assert.assertEquals(1, strings.size());
       Assert.assertEquals(TEST_DB_FILE_CONTENT, strings.get(0));
     }
@@ -222,7 +223,7 @@ private void assertExampleChunkFileIsGood(Path chunkDirPath)
 
     try (FileInputStream testFile = new FileInputStream(chunkFile.toFile())) {
       List<String> strings = IOUtils
-          .readLines(testFile, Charset.forName(StandardCharsets.UTF_8.name()));
+          .readLines(testFile, Charset.forName(UTF_8.name()));
       Assert.assertEquals(1, strings.size());
       Assert.assertEquals(TEST_CHUNK_FILE_CONTENT, strings.get(0));
     }

hadoop-hdds/container-service/src/test/java/org/apache/hadoop/ozone/container/keyvalue/package-info.java

@@ -0,0 +1,22 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * <p>
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ */
+/**
+ * Chunk Manager Checks.
+ */
+package org.apache.hadoop.ozone.container.keyvalue;

hadoop-hdds/framework/src/main/java/org/apache/hadoop/hdds/server/events/EventQueue.java

@@ -139,6 +139,7 @@ public <PAYLOAD, EVENT_TYPE extends Event<PAYLOAD>> void addHandler(
    * @throws IllegalArgumentException If there is no EventHandler for
    *                                  the specific event.
    */
+  @Override
   public <PAYLOAD, EVENT_TYPE extends Event<PAYLOAD>> void fireEvent(
       EVENT_TYPE event, PAYLOAD payload) {
 
@@ -219,7 +220,9 @@ public void processAll(long timeout) {
       try {
         Thread.sleep(100);
       } catch (InterruptedException e) {
-        e.printStackTrace();
+        LOG.warn("Interrupted exception while sleeping.", e);
+        // We ignore this exception for time being. Review? should we
+        // propogate it back to caller?
       }
 
       if (Time.now() > currentTime + timeout) {
@@ -229,7 +232,7 @@ public void processAll(long timeout) {
       }
     }
   }
-
+  @Override
   public void close() {
 
     isRunning = false;

hadoop-hdds/framework/src/test/java/org/apache/hadoop/hdds/server/events/TestEventWatcher.java

@@ -1,24 +1,21 @@
 /**
- * Licensed to the Apache Software Foundation (ASF) under one
+ * Licensed to the Apache Software Foundation (ASF) under one or more
- * or more contributor license agreements.  See the NOTICE file
+ * contributor license agreements.  See the NOTICE file distributed with this
- * distributed with this work for additional information
+ * work for additional information regarding copyright ownership.  The ASF
- * regarding copyright ownership.  The ASF licenses this file
+ * licenses this file to you under the Apache License, Version 2.0 (the
- * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the License.
- * "License"); you may not use this file except in compliance
+ * You may obtain a copy of the License at
- * with the License.  You may obtain a copy of the License at
  * <p>
  * http://www.apache.org/licenses/LICENSE-2.0
  * <p>
  * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
- * See the License for the specific language governing permissions and
+ * License for the specific language governing permissions and limitations under
- * limitations under the License.
+ * the License.
  */
 package org.apache.hadoop.hdds.server.events;
 
-import java.util.List;
-import java.util.Objects;
 import org.apache.hadoop.hdds.HddsIdFactory;
 import org.apache.hadoop.metrics2.lib.DefaultMetricsSystem;
 import org.apache.hadoop.ozone.lease.LeaseManager;
@@ -27,6 +24,9 @@
 import org.junit.Before;
 import org.junit.Test;
 
+import java.util.List;
+import java.util.Objects;
+
 /**
  * Test the basic functionality of event watcher.
  */
@@ -41,7 +41,7 @@ public class TestEventWatcher {
   private static final TypedEvent<ReplicationCompletedEvent>
       REPLICATION_COMPLETED = new TypedEvent<>(ReplicationCompletedEvent.class);
 
-  LeaseManager<Long> leaseManager;
+  private LeaseManager<Long> leaseManager;
 
   @Before
   public void startLeaseManager() {
@@ -56,7 +56,6 @@ public void stopLeaseManager() {
     DefaultMetricsSystem.shutdown();
   }
 
-
   @Test
   public void testEventHandling() throws InterruptedException {
     EventQueue queue = new EventQueue();
@@ -180,7 +179,7 @@ public void testMetrics() throws InterruptedException {
 
     queue.fireEvent(REPLICATION_COMPLETED, event1Completed);
 
-    Thread.sleep(2200l);
+    Thread.sleep(2200L);
 
     //until now: 3 in-progress activities are tracked with three
     // UnderreplicatedEvents. The first one is completed, the remaining two
@@ -206,22 +205,24 @@ public void testMetrics() throws InterruptedException {
         REPLICATION_COMPLETED, leaseManager);
   }
 
-  private class CommandWatcherExample
+  private static class CommandWatcherExample
       extends EventWatcher<UnderreplicatedEvent, ReplicationCompletedEvent> {
 
-    public CommandWatcherExample(Event<UnderreplicatedEvent> startEvent,
+    CommandWatcherExample(Event<UnderreplicatedEvent> startEvent,
         Event<ReplicationCompletedEvent> completionEvent,
         LeaseManager<Long> leaseManager) {
       super("TestCommandWatcher", startEvent, completionEvent, leaseManager);
     }
 
     @Override
-    protected void onTimeout(EventPublisher publisher, UnderreplicatedEvent payload) {
+    protected void onTimeout(EventPublisher publisher,
+        UnderreplicatedEvent payload) {
       publisher.fireEvent(UNDER_REPLICATED, payload);
     }
 
     @Override
-    protected void onFinished(EventPublisher publisher, UnderreplicatedEvent payload) {
+    protected void onFinished(EventPublisher publisher,
+        UnderreplicatedEvent payload) {
       //Good job. We did it.
     }
 
@@ -240,13 +241,14 @@ private static class ReplicationCompletedEvent
 
     private final String datanodeId;
 
-    public ReplicationCompletedEvent(long id, String containerId,
+    ReplicationCompletedEvent(long id, String containerId,
         String datanodeId) {
       this.id = id;
       this.containerId = containerId;
       this.datanodeId = datanodeId;
     }
 
+    @Override
     public long getId() {
       return id;
     }
@@ -279,11 +281,12 @@ private static class UnderreplicatedEvent
 
     private final String containerId;
 
-    public UnderreplicatedEvent(long id, String containerId) {
+    UnderreplicatedEvent(long id, String containerId) {
       this.containerId = containerId;
       this.id = id;
     }
 
+    @Override
     public long getId() {
       return id;
     }

hadoop-hdds/framework/src/test/java/org/apache/hadoop/hdds/server/events/package-info.java

@@ -0,0 +1,22 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * <p>
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ */
+/**
+ * Tests for Event Watcher.
+ */
+package org.apache.hadoop.hdds.server.events;

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/block/PendingDeleteStatusList.java

@@ -19,9 +19,12 @@
 
 import org.apache.hadoop.hdds.protocol.DatanodeDetails;
 
-import java.util.LinkedList;
+import java.util.ArrayList;
 import java.util.List;
 
+/**
+ * Pending Deletes in the block space.
+ */
 public class PendingDeleteStatusList {
 
   private List<PendingDeleteStatus> pendingDeleteStatuses;
@@ -29,7 +32,7 @@ public class PendingDeleteStatusList {
 
   public PendingDeleteStatusList(DatanodeDetails datanodeDetails) {
     this.datanodeDetails = datanodeDetails;
-    pendingDeleteStatuses = new LinkedList<>();
+    pendingDeleteStatuses = new ArrayList<>();
   }
 
   public void addPendingDeleteStatus(long dnDeleteTransactionId,
@@ -39,6 +42,9 @@ public void addPendingDeleteStatus(long dnDeleteTransactionId,
             containerId));
   }
 
+  /**
+   * Status of pending deletes.
+   */
   public static class PendingDeleteStatus {
     private long dnDeleteTransactionId;
     private long scmDeleteTransactionId;

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/chillmode/ChillModePrecheck.java

@@ -44,6 +44,7 @@ public ChillModePrecheck(Configuration conf) {
     }
   }
 
+  @Override
   public boolean check(ScmOps op) throws SCMException {
     if (inChillMode.get() && ChillModeRestrictedOps
         .isRestrictedInChillMode(op)) {

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/container/ContainerReplica.java

@@ -134,6 +134,16 @@ public static ContainerReplicaBuilder newBuilder() {
     return new ContainerReplicaBuilder();
   }
 
+  @Override
+  public String toString() {
+    return "ContainerReplica{" +
+        "containerID=" + containerID +
+        ", datanodeDetails=" + datanodeDetails +
+        ", placeOfBirth=" + placeOfBirth +
+        ", sequenceId=" + sequenceId +
+        '}';
+  }
+
   /**
    * Used for building ContainerReplica instance.
    */
@@ -148,12 +158,12 @@ public static class ContainerReplicaBuilder {
     /**
      * Set Container Id.
      *
-     * @param containerId ContainerID
+     * @param cID ContainerID
      * @return ContainerReplicaBuilder
      */
     public ContainerReplicaBuilder setContainerID(
-        final ContainerID containerId) {
+        final ContainerID cID) {
-      containerID = containerId;
+      this.containerID = cID;
       return this;
     }
 

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/container/placement/algorithms/SCMCommonPolicy.java

@@ -27,7 +27,7 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.util.LinkedList;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Random;
 import java.util.stream.Collectors;
@@ -102,7 +102,7 @@ public Configuration getConf() {
    * @return list of datanodes chosen.
    * @throws SCMException SCM exception.
    */
-
+  @Override
   public List<DatanodeDetails> chooseDatanodes(
       List<DatanodeDetails> excludedNodes,
       int nodesRequired, final long sizeRequired) throws SCMException {
@@ -167,7 +167,7 @@ private boolean hasEnoughSpace(DatanodeDetails datanodeDetails,
   public List<DatanodeDetails> getResultSet(
       int nodesRequired, List<DatanodeDetails> healthyNodes)
       throws SCMException {
-    List<DatanodeDetails> results = new LinkedList<>();
+    List<DatanodeDetails> results = new ArrayList<>();
     for (int x = 0; x < nodesRequired; x++) {
       // invoke the choose function defined in the derived classes.
       DatanodeDetails nodeId = chooseNode(healthyNodes);

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/container/placement/algorithms/SCMContainerPlacementRandom.java

@@ -83,6 +83,7 @@ public List<DatanodeDetails> chooseDatanodes(
    * @param healthyNodes - all healthy datanodes.
    * @return one randomly chosen datanode that from two randomly chosen datanode
    */
+  @Override
   public DatanodeDetails chooseNode(final List<DatanodeDetails> healthyNodes) {
     DatanodeDetails selectedNode =
         healthyNodes.get(getRand().nextInt(healthyNodes.size()));

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/container/placement/metrics/DatanodeMetric.java

@@ -23,7 +23,7 @@
  * DatanodeMetric acts as the basis for all the metric that is used in
  * comparing 2 datanodes.
  */
-public interface DatanodeMetric<T, S> extends Comparable<T> {
+public interface DatanodeMetric<T, S>  {
 
   /**
    * Some syntactic sugar over Comparable interface. This makes code easier to
@@ -87,5 +87,4 @@ public interface DatanodeMetric<T, S> extends Comparable<T> {
    */
   void subtract(T value);
 
-
 }

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/container/placement/metrics/LongMetric.java

@@ -136,7 +136,6 @@ public void subtract(Long subValue) {
    * @throws ClassCastException   if the specified object's type prevents it
    *                              from being compared to this object.
    */
-  @Override
   public int compareTo(Long o) {
     return Long.compare(this.value, o);
   }

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/container/placement/metrics/SCMNodeMetric.java

@@ -191,7 +191,7 @@ public void subtract(SCMNodeStat value) {
    * @throws ClassCastException   if the specified object's type prevents it
    *                              from being compared to this object.
    */
-  @Override
+  //@Override
   public int compareTo(SCMNodeStat o) {
     if (isEqual(o)) {
       return 0;

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/container/placement/metrics/SCMNodeStat.java

@@ -52,6 +52,7 @@ public SCMNodeStat(long capacity, long used, long remaining) {
   /**
    * @return the total configured capacity of the node.
    */
+  @Override
   public LongMetric getCapacity() {
     return capacity;
   }
@@ -59,6 +60,7 @@ public LongMetric getCapacity() {
   /**
    * @return the total SCM used space on the node.
    */
+  @Override
   public LongMetric getScmUsed() {
     return scmUsed;
   }
@@ -66,6 +68,7 @@ public LongMetric getScmUsed() {
   /**
    * @return the total remaining space available on the node.
    */
+  @Override
   public LongMetric getRemaining() {
     return remaining;
   }
@@ -77,12 +80,9 @@ public LongMetric getRemaining() {
    * @param newUsed in bytes
    * @param newRemaining in bytes
    */
+  @Override
   @VisibleForTesting
   public void set(long newCapacity, long newUsed, long newRemaining) {
-    Preconditions.checkNotNull(newCapacity, "Capacity cannot be null");
-    Preconditions.checkNotNull(newUsed, "used cannot be null");
-    Preconditions.checkNotNull(newRemaining, "remaining cannot be null");
-
     Preconditions.checkArgument(newCapacity >= 0, "Capacity cannot be " +
         "negative.");
     Preconditions.checkArgument(newUsed >= 0, "used space cannot be " +
@@ -101,6 +101,7 @@ public void set(long newCapacity, long newUsed, long newRemaining) {
    * @param stat Nodestat.
    * @return SCMNodeStat
    */
+  @Override
   public SCMNodeStat add(NodeStat stat) {
     this.capacity.set(this.getCapacity().get() + stat.getCapacity().get());
     this.scmUsed.set(this.getScmUsed().get() + stat.getScmUsed().get());
@@ -114,6 +115,7 @@ public SCMNodeStat add(NodeStat stat) {
    * @param stat SCMNodeStat.
    * @return Modified SCMNodeStat
    */
+  @Override
   public SCMNodeStat subtract(NodeStat stat) {
     this.capacity.set(this.getCapacity().get() - stat.getCapacity().get());
     this.scmUsed.set(this.getScmUsed().get() - stat.getScmUsed().get());

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/container/replication/ReplicationActivityStatus.java

@@ -48,12 +48,13 @@ public ReplicationActivityStatus(){
     replicationStatusListener = new ReplicationStatusListener();
     chillModeStatusListener = new ChillModeStatusListener();
   }
-
+  @Override
   public boolean isReplicationEnabled() {
     return replicationEnabled.get();
   }
 
   @VisibleForTesting
+  @Override
   public void setReplicationEnabled(boolean enabled) {
     replicationEnabled.set(enabled);
   }

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/container/replication/ReplicationManager.java

@@ -98,6 +98,7 @@ public void start() {
     threadFactory.newThread(this).start();
   }
 
+  @Override
   public void run() {
 
     while (running) {
@@ -168,6 +169,7 @@ public void run() {
 
         } else if (deficit < 0) {
           //TODO: too many replicas. Not handled yet.
+          LOG.debug("Too many replicas is not handled yet.");
         }
 
       } catch (Exception e) {

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/node/CommandQueue.java

@@ -22,8 +22,8 @@
 import org.apache.hadoop.ozone.protocol.commands.SCMCommand;
 import org.apache.hadoop.util.Time;
 
+import java.util.ArrayList;
 import java.util.HashMap;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.UUID;
@@ -39,7 +39,7 @@
  */
 public class CommandQueue {
   // This list is used as default return value.
-  private static final List<SCMCommand> DEFAULT_LIST = new LinkedList<>();
+  private static final List<SCMCommand> DEFAULT_LIST = new ArrayList<>();
   private final Map<UUID, Commands> commandMap;
   private final Lock lock;
   private long commandsInQueue;
@@ -136,7 +136,7 @@ private static class Commands {
      * Constructs a Commands class.
      */
     Commands() {
-      commands = new LinkedList<>();
+      commands = new ArrayList<>();
       updateTime = 0;
       readTime = 0;
     }
@@ -182,7 +182,7 @@ public void add(SCMCommand command) {
      */
     public List<SCMCommand> getCommands() {
       List<SCMCommand> temp = this.commands;
-      this.commands = new LinkedList<>();
+      this.commands = new ArrayList<>();
       readTime = Time.monotonicNow();
       return temp;
     }

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/node/NodeStateManager.java

@@ -144,6 +144,8 @@ public NodeStateManager(Configuration conf, EventPublisher eventPublisher) {
     executorService = HadoopExecutors.newScheduledThreadPool(1,
         new ThreadFactoryBuilder().setDaemon(true)
             .setNameFormat("SCM Heartbeat Processing Thread - %d").build());
+    //BUG:BUG TODO: The return value is ignored, if an exception is thrown in
+    // the executing funtion, it will be ignored.
     executorService.schedule(this, heartbeatCheckerIntervalMs,
         TimeUnit.MILLISECONDS);
   }
@@ -331,7 +333,7 @@ public List<DatanodeDetails> getDeadNodes() {
    * @return list of nodes
    */
   public List<DatanodeDetails> getNodes(NodeState state) {
-    List<DatanodeDetails> nodes = new LinkedList<>();
+    List<DatanodeDetails> nodes = new ArrayList<>();
     nodeStateMap.getNodes(state).forEach(
         uuid -> {
           try {
@@ -352,7 +354,7 @@ public List<DatanodeDetails> getNodes(NodeState state) {
    * @return all the managed nodes
    */
   public List<DatanodeDetails> getAllNodes() {
-    List<DatanodeDetails> nodes = new LinkedList<>();
+    List<DatanodeDetails> nodes = new ArrayList<>();
     nodeStateMap.getAllNodes().forEach(
         uuid -> {
           try {
@@ -613,6 +615,8 @@ public void run() {
 
     if (!Thread.currentThread().isInterrupted() &&
         !executorService.isShutdown()) {
+      //BUGBUG: The return future needs to checked here to make sure the
+      // exceptions are handled correctly.
       executorService.schedule(this, heartbeatCheckerIntervalMs,
           TimeUnit.MILLISECONDS);
     } else {

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/node/states/Node2ContainerMap.java

@@ -59,6 +59,7 @@ public Set<ContainerID> getContainers(UUID datanode) {
    * @param datanodeID   -- Datanode UUID
    * @param containerIDs - List of ContainerIDs.
    */
+  @Override
   public void insertNewDatanode(UUID datanodeID, Set<ContainerID> containerIDs)
       throws SCMException {
     super.insertNewDatanode(datanodeID, containerIDs);
@@ -84,6 +85,7 @@ public void setContainersForDatanode(UUID datanodeID,
   }
 
   @VisibleForTesting
+  @Override
   public int size() {
     return dn2ObjectMap.size();
   }

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/node/states/NodeStateMap.java

@@ -172,7 +172,7 @@ public DatanodeInfo getNodeInfo(UUID uuid) throws NodeNotFoundException {
   public List<UUID> getNodes(NodeState state) {
     lock.readLock().lock();
     try {
-      return new LinkedList<>(stateMap.get(state));
+      return new ArrayList<>(stateMap.get(state));
     } finally {
       lock.readLock().unlock();
     }
@@ -186,7 +186,7 @@ public List<UUID> getNodes(NodeState state) {
   public List<UUID> getAllNodes() {
     lock.readLock().lock();
     try {
-      return new LinkedList<>(nodeMap.keySet());
+      return new ArrayList<>(nodeMap.keySet());
     } finally {
       lock.readLock().unlock();
     }

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/pipeline/SCMPipelineManager.java

@@ -30,6 +30,7 @@
 import org.apache.hadoop.hdds.server.ServerUtils;
 import org.apache.hadoop.hdds.server.events.EventPublisher;
 import org.apache.hadoop.ozone.OzoneConsts;
+import org.apache.hadoop.utils.MetadataKeyFilters;
 import org.apache.hadoop.utils.MetadataStore;
 import org.apache.hadoop.utils.MetadataStoreBuilder;
 import org.slf4j.Logger;
@@ -94,7 +95,8 @@ private void initializePipelineState() throws IOException {
       return;
     }
     List<Map.Entry<byte[], byte[]>> pipelines =
-        pipelineStore.getSequentialRangeKVs(null, Integer.MAX_VALUE, null);
+        pipelineStore.getSequentialRangeKVs(null, Integer.MAX_VALUE,
+            (MetadataKeyFilters.MetadataKeyFilter[])null);
 
     for (Map.Entry<byte[], byte[]> entry : pipelines) {
       Pipeline pipeline = Pipeline.getFromProtobuf(

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/server/SCMClientProtocolServer.java

@@ -58,7 +58,6 @@
 import java.io.IOException;
 import java.net.InetSocketAddress;
 import java.util.ArrayList;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Set;
 import java.util.TreeSet;
@@ -354,7 +353,7 @@ public boolean forceExitChillMode() throws IOException {
    */
   public List<DatanodeDetails> queryNode(HddsProtos.NodeState state) {
     Preconditions.checkNotNull(state, "Node Query set cannot be null");
-    return new LinkedList<>(queryNodeState(state));
+    return new ArrayList<>(queryNodeState(state));
   }
 
   @VisibleForTesting

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/server/SCMDatanodeProtocolServer.java

@@ -89,7 +89,7 @@
 
 import java.io.IOException;
 import java.net.InetSocketAddress;
-import java.util.LinkedList;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.stream.Collectors;
 
@@ -225,7 +225,7 @@ public static SCMRegisteredResponseProto getRegisteredResponse(
   @Override
   public SCMHeartbeatResponseProto sendHeartbeat(
       SCMHeartbeatRequestProto heartbeat) throws IOException {
-    List<SCMCommandProto> cmdResponses = new LinkedList<>();
+    List<SCMCommandProto> cmdResponses = new ArrayList<>();
     for (SCMCommand cmd : heartbeatDispatcher.dispatch(heartbeat)) {
       cmdResponses.add(getCommandResponse(cmd));
     }

hadoop-hdds/server-scm/src/test/java/org/apache/hadoop/hdds/scm/TestHddsServerUtils.java

@@ -42,7 +42,7 @@
 import static org.junit.Assert.assertTrue;
 
 /**
- * Unit tests for {@link HddsServerUtil}
+ * Unit tests for {@link HddsServerUtil}.
  */
 public class TestHddsServerUtils {
   public static final Logger LOG = LoggerFactory.getLogger(
@@ -58,6 +58,7 @@ public class TestHddsServerUtils {
    * Test getting OZONE_SCM_DATANODE_ADDRESS_KEY with port.
    */
   @Test
+  @SuppressWarnings("StringSplitter")
   public void testGetDatanodeAddressWithPort() {
     final String scmHost = "host123:100";
     final Configuration conf = new OzoneConfiguration();
@@ -78,8 +79,8 @@ public void testGetDatanodeAddressWithoutPort() {
     conf.set(OZONE_SCM_DATANODE_ADDRESS_KEY, scmHost);
     final InetSocketAddress address =
         HddsServerUtil.getScmAddressForDataNodes(conf);
-    assertEquals(address.getHostName(), scmHost);
+    assertEquals(scmHost, address.getHostName());
-    assertEquals(address.getPort(), OZONE_SCM_DATANODE_PORT_DEFAULT);
+    assertEquals(OZONE_SCM_DATANODE_PORT_DEFAULT, address.getPort());
   }
 
   /**
@@ -93,8 +94,8 @@ public void testDatanodeAddressFallbackToClientNoPort() {
     conf.set(OZONE_SCM_CLIENT_ADDRESS_KEY, scmHost);
     final InetSocketAddress address =
         HddsServerUtil.getScmAddressForDataNodes(conf);
-    assertEquals(address.getHostName(), scmHost);
+    assertEquals(scmHost, address.getHostName());
-    assertEquals(address.getPort(), OZONE_SCM_DATANODE_PORT_DEFAULT);
+    assertEquals(OZONE_SCM_DATANODE_PORT_DEFAULT, address.getPort());
   }
 
   /**
@@ -103,6 +104,7 @@ public void testDatanodeAddressFallbackToClientNoPort() {
    * OZONE_SCM_CLIENT_ADDRESS_KEY should be ignored.
    */
   @Test
+  @SuppressWarnings("StringSplitter")
   public void testDatanodeAddressFallbackToClientWithPort() {
     final String scmHost = "host123:100";
     final Configuration conf = new OzoneConfiguration();
@@ -124,8 +126,8 @@ public void testDatanodeAddressFallbackToScmNamesNoPort() {
     conf.set(OZONE_SCM_NAMES, scmHost);
     final InetSocketAddress address =
         HddsServerUtil.getScmAddressForDataNodes(conf);
-    assertEquals(address.getHostName(), scmHost);
+    assertEquals(scmHost, address.getHostName());
-    assertEquals(address.getPort(), OZONE_SCM_DATANODE_PORT_DEFAULT);
+    assertEquals(OZONE_SCM_DATANODE_PORT_DEFAULT, address.getPort());
   }
 
   /**
@@ -134,6 +136,7 @@ public void testDatanodeAddressFallbackToScmNamesNoPort() {
    * defined by OZONE_SCM_NAMES should be ignored.
    */
   @Test
+  @SuppressWarnings("StringSplitter")
   public void testDatanodeAddressFallbackToScmNamesWithPort() {
     final String scmHost = "host123:100";
     final Configuration conf = new OzoneConfiguration();
@@ -141,7 +144,7 @@ public void testDatanodeAddressFallbackToScmNamesWithPort() {
     final InetSocketAddress address =
         HddsServerUtil.getScmAddressForDataNodes(conf);
     assertEquals(address.getHostName(), scmHost.split(":")[0]);
-    assertEquals(address.getPort(), OZONE_SCM_DATANODE_PORT_DEFAULT);
+    assertEquals(OZONE_SCM_DATANODE_PORT_DEFAULT, address.getPort());
   }
 
   /**

hadoop-hdds/server-scm/src/test/java/org/apache/hadoop/hdds/scm/node/TestNodeManager.java

@@ -48,7 +48,7 @@
 
 import java.io.File;
 import java.io.IOException;
-import java.util.LinkedList;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.UUID;
 import java.util.concurrent.TimeUnit;
@@ -378,12 +378,9 @@ public void testScmDetectStaleAndDeadNode() throws IOException,
    * Check for NPE when datanodeDetails is passed null for sendHeartbeat.
    *
    * @throws IOException
-   * @throws InterruptedException
-   * @throws TimeoutException
    */
   @Test
-  public void testScmCheckForErrorOnNullDatanodeDetails() throws IOException,
+  public void testScmCheckForErrorOnNullDatanodeDetails() throws IOException {
-      InterruptedException, TimeoutException {
     try (SCMNodeManager nodeManager = createNodeManager(getConf())) {
       nodeManager.processHeartbeat(null);
     } catch (NullPointerException npe) {
@@ -588,7 +585,7 @@ private void heartbeatNodeSet(SCMNodeManager manager,
    */
   private List<DatanodeDetails> createNodeSet(SCMNodeManager nodeManager, int
       count) {
-    List<DatanodeDetails> list = new LinkedList<>();
+    List<DatanodeDetails> list = new ArrayList<>();
     for (int x = 0; x < count; x++) {
       DatanodeDetails datanodeDetails = TestUtils
           .createRandomDatanodeAndRegister(nodeManager);
@@ -943,7 +940,7 @@ public void testScmNodeReportUpdate() throws IOException,
   }
 
   @Test
-  public void testHandlingSCMCommandEvent() {
+  public void testHandlingSCMCommandEvent() throws IOException {
     OzoneConfiguration conf = getConf();
     conf.getTimeDuration(ScmConfigKeys.OZONE_SCM_HEARTBEAT_PROCESS_INTERVAL,
         100, TimeUnit.MILLISECONDS);
@@ -974,6 +971,7 @@ public void testHandlingSCMCommandEvent() {
           .assertEquals(command.get(0).getClass(), CloseContainerCommand.class);
     } catch (IOException e) {
       e.printStackTrace();
+      throw  e;
     }
   }
 

hadoop-hdds/server-scm/src/test/java/org/apache/hadoop/hdds/scm/node/TestSCMNodeStorageStatMap.java

@@ -150,22 +150,22 @@ public void testProcessNodeReportCheckOneNode() throws IOException {
         path, reportCapacity, reportScmUsed, reportRemaining, null);
     StorageReportResult result =
         map.processNodeReport(key, TestUtils.createNodeReport(storageReport));
-    Assert.assertEquals(result.getStatus(),
+    Assert.assertEquals(SCMNodeStorageStatMap.ReportStatus.ALL_IS_WELL,
-        SCMNodeStorageStatMap.ReportStatus.ALL_IS_WELL);
+        result.getStatus());
     StorageContainerDatanodeProtocolProtos.NodeReportProto.Builder nrb =
         NodeReportProto.newBuilder();
     StorageReportProto srb = reportSet.iterator().next().getProtoBufMessage();
     reportList.add(srb);
     result = map.processNodeReport(key, TestUtils.createNodeReport(reportList));
-    Assert.assertEquals(result.getStatus(),
+    Assert.assertEquals(SCMNodeStorageStatMap.ReportStatus.ALL_IS_WELL,
-        SCMNodeStorageStatMap.ReportStatus.ALL_IS_WELL);
+        result.getStatus());
 
     reportList.add(TestUtils
         .createStorageReport(UUID.randomUUID(), path, reportCapacity,
             reportCapacity, 0, null));
     result = map.processNodeReport(key, TestUtils.createNodeReport(reportList));
-    Assert.assertEquals(result.getStatus(),
+    Assert.assertEquals(SCMNodeStorageStatMap.ReportStatus.STORAGE_OUT_OF_SPACE,
-        SCMNodeStorageStatMap.ReportStatus.STORAGE_OUT_OF_SPACE);
+        result.getStatus());
     // Mark a disk failed 
     StorageReportProto srb2 = StorageReportProto.newBuilder()
         .setStorageUuid(UUID.randomUUID().toString())
@@ -174,8 +174,8 @@ public void testProcessNodeReportCheckOneNode() throws IOException {
     reportList.add(srb2);
     nrb.addAllStorageReport(reportList);
     result = map.processNodeReport(key, nrb.addStorageReport(srb).build());
-    Assert.assertEquals(result.getStatus(),
+    Assert.assertEquals(SCMNodeStorageStatMap.ReportStatus
-        SCMNodeStorageStatMap.ReportStatus.FAILED_AND_OUT_OF_SPACE_STORAGE);
+        .FAILED_AND_OUT_OF_SPACE_STORAGE, result.getStatus());
 
   }
 

hadoop-hdds/server-scm/src/test/java/org/apache/hadoop/hdds/scm/node/states/TestNode2ContainerMap.java

@@ -51,7 +51,7 @@ private void generateData() {
     for (int dnIndex = 1; dnIndex <= DATANODE_COUNT; dnIndex++) {
       TreeSet<ContainerID> currentSet = new TreeSet<>();
       for (int cnIndex = 1; cnIndex <= CONTAINER_COUNT; cnIndex++) {
-        long currentCnIndex = (dnIndex * CONTAINER_COUNT) + cnIndex;
+        long currentCnIndex = (long) (dnIndex * CONTAINER_COUNT) + cnIndex;
         currentSet.add(new ContainerID(currentCnIndex));
       }
       testData.put(UUID.randomUUID(), currentSet);
@@ -115,8 +115,8 @@ public void testProcessReportCheckOneNode() throws SCMException {
     map.insertNewDatanode(key, values);
     Assert.assertTrue(map.isKnownDatanode(key));
     ReportResult result = map.processReport(key, values);
-    Assert.assertEquals(result.getStatus(),
+    Assert.assertEquals(ReportResult.ReportStatus.ALL_IS_WELL,
-        ReportResult.ReportStatus.ALL_IS_WELL);
+        result.getStatus());
   }
 
   @Test

hadoop-hdds/server-scm/src/test/java/org/apache/hadoop/ozone/container/placement/TestDatanodeMetrics.java

@@ -19,9 +19,8 @@
 
 import org.apache.hadoop.hdds.scm.container.placement.metrics.SCMNodeMetric;
 import org.apache.hadoop.hdds.scm.container.placement.metrics.SCMNodeStat;
-import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
+
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
@@ -30,20 +29,18 @@
  * Tests that test Metrics that support placement.
  */
 public class TestDatanodeMetrics {
-  @Rule
-  public ExpectedException exception = ExpectedException.none();
   @Test
   public void testSCMNodeMetric() {
     SCMNodeStat stat = new SCMNodeStat(100L, 10L, 90L);
     assertEquals((long) stat.getCapacity().get(), 100L);
-    assertEquals((long) stat.getScmUsed().get(), 10L);
+    assertEquals(10L, (long) stat.getScmUsed().get());
-    assertEquals((long) stat.getRemaining().get(), 90L);
+    assertEquals(90L, (long) stat.getRemaining().get());
     SCMNodeMetric metric = new SCMNodeMetric(stat);
 
     SCMNodeStat newStat = new SCMNodeStat(100L, 10L, 90L);
-    assertEquals((long) stat.getCapacity().get(), 100L);
+    assertEquals(100L, (long) stat.getCapacity().get());
-    assertEquals((long) stat.getScmUsed().get(), 10L);
+    assertEquals(10L, (long) stat.getScmUsed().get());
-    assertEquals((long) stat.getRemaining().get(), 90L);
+    assertEquals(90L, (long) stat.getRemaining().get());
 
     SCMNodeMetric newMetric = new SCMNodeMetric(newStat);
     assertTrue(metric.isEqual(newMetric.get()));

hadoop-ozone/client/src/main/java/org/apache/hadoop/ozone/client/ObjectStore.java

@@ -124,6 +124,7 @@ public String getOzoneBucketMapping(String s3BucketName) throws IOException {
    * @return String - Ozone Volume name.
    * @throws IOException - Throws if the s3Bucket does not exist.
    */
+  @SuppressWarnings("StringSplitter")
   public String getOzoneVolumeName(String s3BucketName) throws IOException {
     String mapping = getOzoneBucketMapping(s3BucketName);
     return mapping.split("/")[0];
@@ -136,6 +137,7 @@ public String getOzoneVolumeName(String s3BucketName) throws IOException {
    * @return String - Ozone bucket Name.
    * @throws IOException - Throws if the s3bucket does not exist.
    */
+  @SuppressWarnings("StringSplitter")
   public String getOzoneBucketName(String s3BucketName) throws IOException {
     String mapping = getOzoneBucketMapping(s3BucketName);
     return mapping.split("/")[1];

hadoop-ozone/client/src/main/java/org/apache/hadoop/ozone/client/rpc/RpcClient.java

@@ -610,6 +610,7 @@ public String getOzoneBucketMapping(String s3BucketName) throws IOException {
   }
 
   @Override
+  @SuppressWarnings("StringSplitter")
   public String getOzoneVolumeName(String s3BucketName) throws IOException {
     String mapping = getOzoneBucketMapping(s3BucketName);
     return mapping.split("/")[0];
@@ -617,6 +618,7 @@ public String getOzoneVolumeName(String s3BucketName) throws IOException {
   }
 
   @Override
+  @SuppressWarnings("StringSplitter")
   public String getOzoneBucketName(String s3BucketName) throws IOException {
     String mapping = getOzoneBucketMapping(s3BucketName);
     return mapping.split("/")[1];

hadoop-ozone/client/src/test/java/org/apache/hadoop/ozone/client/TestHddsClientUtils.java

@@ -40,11 +40,12 @@
 
 /**
  * This test class verifies the parsing of SCM endpoint config settings. The
- * parsing logic is in {@link org.apache.hadoop.hdds.scm.client.HddsClientUtils}.
+ * parsing logic is in
+ * {@link org.apache.hadoop.hdds.scm.client.HddsClientUtils}.
  */
 public class TestHddsClientUtils {
   @Rule
-  public Timeout timeout = new Timeout(300_000);
+  public Timeout timeout = new Timeout(300000);
 
   @Rule
   public ExpectedException thrown= ExpectedException.none();
@@ -114,13 +115,14 @@ public void testBlockClientFallbackToClientNoPort() {
     final String scmHost = "host123";
     final Configuration conf = new OzoneConfiguration();
     conf.set(OZONE_SCM_CLIENT_ADDRESS_KEY, scmHost);
-    final InetSocketAddress address =HddsUtils.getScmAddressForBlockClients(
+    final InetSocketAddress address = HddsUtils.getScmAddressForBlockClients(
         conf);
-    assertEquals(address.getHostName(), scmHost);
+    assertEquals(scmHost, address.getHostName());
-    assertEquals(address.getPort(), OZONE_SCM_BLOCK_CLIENT_PORT_DEFAULT);
+    assertEquals(OZONE_SCM_BLOCK_CLIENT_PORT_DEFAULT, address.getPort());
   }
 
   @Test
+  @SuppressWarnings("StringSplitter")
   public void testBlockClientFallbackToClientWithPort() {
     // When OZONE_SCM_BLOCK_CLIENT_ADDRESS_KEY is undefined it should
     // fallback to OZONE_SCM_CLIENT_ADDRESS_KEY.
@@ -132,8 +134,8 @@ public void testBlockClientFallbackToClientWithPort() {
     conf.set(OZONE_SCM_CLIENT_ADDRESS_KEY, scmHost);
     final InetSocketAddress address =HddsUtils.getScmAddressForBlockClients(
         conf);
-    assertEquals(address.getHostName(), scmHost.split(":")[0]);
+    assertEquals(scmHost.split(":")[0], address.getHostName());
-    assertEquals(address.getPort(), OZONE_SCM_BLOCK_CLIENT_PORT_DEFAULT);
+    assertEquals(OZONE_SCM_BLOCK_CLIENT_PORT_DEFAULT, address.getPort());
   }
 
   @Test
@@ -143,13 +145,14 @@ public void testBlockClientFallbackToScmNamesNoPort() {
     final String scmHost = "host456";
     final Configuration conf = new OzoneConfiguration();
     conf.set(OZONE_SCM_NAMES, scmHost);
-    final InetSocketAddress address =HddsUtils.getScmAddressForBlockClients(
+    final InetSocketAddress address = HddsUtils.getScmAddressForBlockClients(
         conf);
-    assertEquals(address.getHostName(), scmHost);
+    assertEquals(scmHost, address.getHostName());
-    assertEquals(address.getPort(), OZONE_SCM_BLOCK_CLIENT_PORT_DEFAULT);
+    assertEquals(OZONE_SCM_BLOCK_CLIENT_PORT_DEFAULT, address.getPort());
   }
 
   @Test
+  @SuppressWarnings("StringSplitter")
   public void testBlockClientFallbackToScmNamesWithPort() {
     // When OZONE_SCM_BLOCK_CLIENT_ADDRESS_KEY and OZONE_SCM_CLIENT_ADDRESS_KEY
     // are undefined it should fallback to OZONE_SCM_NAMES.
@@ -159,10 +162,10 @@ public void testBlockClientFallbackToScmNamesWithPort() {
     final String scmHost = "host456:200";
     final Configuration conf = new OzoneConfiguration();
     conf.set(OZONE_SCM_NAMES, scmHost);
-    final InetSocketAddress address =HddsUtils.getScmAddressForBlockClients(
+    final InetSocketAddress address = HddsUtils.getScmAddressForBlockClients(
         conf);
-    assertEquals(address.getHostName(), scmHost.split(":")[0]);
+    assertEquals(scmHost.split(":")[0], address.getHostName());
-    assertEquals(address.getPort(), OZONE_SCM_BLOCK_CLIENT_PORT_DEFAULT);
+    assertEquals(OZONE_SCM_BLOCK_CLIENT_PORT_DEFAULT, address.getPort());
   }
 
   @Test
@@ -172,12 +175,13 @@ public void testClientFallbackToScmNamesNoPort() {
     final String scmHost = "host456";
     final Configuration conf = new OzoneConfiguration();
     conf.set(OZONE_SCM_NAMES, scmHost);
-    final InetSocketAddress address =HddsUtils.getScmAddressForClients(conf);
+    final InetSocketAddress address = HddsUtils.getScmAddressForClients(conf);
-    assertEquals(address.getHostName(), scmHost);
+    assertEquals(scmHost, address.getHostName());
-    assertEquals(address.getPort(), OZONE_SCM_CLIENT_PORT_DEFAULT);
+    assertEquals(OZONE_SCM_CLIENT_PORT_DEFAULT, address.getPort());
   }
 
   @Test
+  @SuppressWarnings("StringSplitter")
   public void testClientFallbackToScmNamesWithPort() {
     // When OZONE_SCM_CLIENT_ADDRESS_KEY is undefined, it should fallback
     // to OZONE_SCM_NAMES.
@@ -187,9 +191,9 @@ public void testClientFallbackToScmNamesWithPort() {
     final String scmHost = "host456:300";
     final Configuration conf = new OzoneConfiguration();
     conf.set(OZONE_SCM_NAMES, scmHost);
-    final InetSocketAddress address =HddsUtils.getScmAddressForClients(conf);
+    final InetSocketAddress address = HddsUtils.getScmAddressForClients(conf);
-    assertEquals(address.getHostName(), scmHost.split(":")[0]);
+    assertEquals(scmHost.split(":")[0], address.getHostName());
-    assertEquals(address.getPort(), OZONE_SCM_CLIENT_PORT_DEFAULT);
+    assertEquals(OZONE_SCM_CLIENT_PORT_DEFAULT, address.getPort());
   }
 
   @Test

hadoop-ozone/common/src/main/java/org/apache/hadoop/ozone/om/helpers/OmOzoneAclMap.java

@@ -34,6 +34,7 @@
 /**
  * This helper class keeps a map of all user and their permissions.
  */
+@SuppressWarnings("ProtocolBufferOrdinal")
 public class OmOzoneAclMap {
   // per Acl Type user:rights map
   private ArrayList<Map<String, OzoneAclRights>> aclMaps;

hadoop-ozone/common/src/main/java/org/apache/hadoop/ozone/web/response/BucketInfo.java

@@ -18,7 +18,7 @@
 package org.apache.hadoop.ozone.web.response;
 
 import java.io.IOException;
-import java.util.LinkedList;
+import java.util.ArrayList;
 import java.util.List;
 
 import org.apache.hadoop.hdds.protocol.StorageType;
@@ -85,7 +85,7 @@ public BucketInfo(String volumeName, String bucketName) {
    * Default constructor for BucketInfo.
    */
   public BucketInfo() {
-    acls = new LinkedList<OzoneAcl>();
+    acls = new ArrayList<>();
   }
 
   /**
@@ -318,7 +318,7 @@ public void setKeyCount(long keyCount) {
    * for the Json serialization.
    */
   @JsonFilter(BUCKET_INFO)
-  class MixIn {
+  static class MixIn {
 
   }
 

hadoop-ozone/common/src/test/java/org/apache/hadoop/ozone/web/TestBucketInfo.java

@@ -18,17 +18,19 @@
 
 package org.apache.hadoop.ozone.web;
 
-
-import org.apache.hadoop.ozone.OzoneAcl;
 import org.apache.hadoop.hdds.protocol.StorageType;
-import org.apache.hadoop.ozone.web.response.BucketInfo;
+import org.apache.hadoop.ozone.OzoneAcl;
 import org.apache.hadoop.ozone.OzoneConsts;
+import org.apache.hadoop.ozone.web.response.BucketInfo;
 import org.junit.Test;
 
 import java.io.IOException;
-import java.util.LinkedList;
+import java.util.ArrayList;
 import java.util.List;
 
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
 /**
  * Test Ozone Bucket Info operation.
  */
@@ -38,7 +40,7 @@ public void testBucketInfoJson() throws IOException {
     BucketInfo bucketInfo = new BucketInfo("volumeName", "bucketName");
     String bucketInfoString = bucketInfo.toJsonString();
     BucketInfo newBucketInfo = BucketInfo.parse(bucketInfoString);
-    assert(bucketInfo.equals(newBucketInfo));
+    assertEquals(bucketInfo, newBucketInfo);
   }
 
   @Test
@@ -46,7 +48,7 @@ public void testBucketInfoDBString() throws IOException {
     BucketInfo bucketInfo = new BucketInfo("volumeName", "bucketName");
     String bucketInfoString = bucketInfo.toDBString();
     BucketInfo newBucketInfo = BucketInfo.parse(bucketInfoString);
-    assert(bucketInfo.equals(newBucketInfo));
+    assertEquals(bucketInfo, newBucketInfo);
   }
 
   @Test
@@ -54,18 +56,17 @@ public void testBucketInfoAddAcls() throws IOException {
     BucketInfo bucketInfo = new BucketInfo("volumeName", "bucketName");
     String bucketInfoString = bucketInfo.toDBString();
     BucketInfo newBucketInfo = BucketInfo.parse(bucketInfoString);
-    assert(bucketInfo.equals(newBucketInfo));
+    assertEquals(bucketInfo, newBucketInfo);
-    List<OzoneAcl> aclList = new LinkedList<>();
+    List<OzoneAcl> aclList = new ArrayList<>();
 
     aclList.add(OzoneAcl.parseAcl("user:bilbo:r"));
     aclList.add(OzoneAcl.parseAcl("user:samwise:rw"));
     newBucketInfo.setAcls(aclList);
 
-    assert(newBucketInfo.getAcls() != null);
+    assertNotNull(newBucketInfo.getAcls());
-    assert(newBucketInfo.getAcls().size() == 2);
+    assertEquals(2, newBucketInfo.getAcls().size());
   }
 
-
   @Test
   public void testBucketInfoVersionAndType() throws IOException {
     BucketInfo bucketInfo = new BucketInfo("volumeName", "bucketName");
@@ -75,7 +76,7 @@ public void testBucketInfoVersionAndType() throws IOException {
     String bucketInfoString = bucketInfo.toDBString();
 
     BucketInfo newBucketInfo = BucketInfo.parse(bucketInfoString);
-    assert(bucketInfo.equals(newBucketInfo));
+    assertEquals(bucketInfo, newBucketInfo);
   }
 
 }

hadoop-ozone/common/src/test/java/org/apache/hadoop/ozone/web/TestQuota.java

@@ -1,19 +1,18 @@
 /**
- * Licensed to the Apache Software Foundation (ASF) under one
+ * Licensed to the Apache Software Foundation (ASF) under one or more
- * or more contributor license agreements.  See the NOTICE file
+ * contributor license agreements.  See the NOTICE file distributed with this
- * distributed with this work for additional information
+ * work for additional information regarding copyright ownership.  The ASF
- * regarding copyright ownership.  The ASF licenses this file
+ * licenses this file to you under the Apache License, Version 2.0 (the
- * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the License.
- * "License"); you may not use this file except in compliance
+ * You may obtain a copy of the License at
- * with the License.  You may obtain a copy of the License at
+ * <p>
- *
  * http://www.apache.org/licenses/LICENSE-2.0
- *
+ * <p>
  * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
- * See the License for the specific language governing permissions and
+ * License for the specific language governing permissions and limitations under
- * limitations under the License.
+ * the License.
  */
 
 package org.apache.hadoop.ozone.web;
@@ -82,29 +81,29 @@ public void testParseQuota() {
   @Test
   public void testVerifyQuota() {
     OzoneQuota qt = OzoneQuota.parseQuota("10TB");
-    assertEquals(qt.getSize(), 10);
+    assertEquals(10, qt.getSize());
-    assertEquals(qt.getUnit(), OzoneQuota.Units.TB);
+    assertEquals(OzoneQuota.Units.TB, qt.getUnit());
-    assertEquals(qt.sizeInBytes(), 10L * (1024L * 1024L * 1024L * 1024L));
+    assertEquals(10L * (1024L * 1024L * 1024L * 1024L), qt.sizeInBytes());
 
     qt = OzoneQuota.parseQuota("10MB");
-    assertEquals(qt.getSize(), 10);
+    assertEquals(10, qt.getSize());
-    assertEquals(qt.getUnit(), OzoneQuota.Units.MB);
+    assertEquals(OzoneQuota.Units.MB, qt.getUnit());
-    assertEquals(qt.sizeInBytes(), 10L * (1024L * 1024L));
+    assertEquals(10L * (1024L * 1024L), qt.sizeInBytes());
 
     qt = OzoneQuota.parseQuota("10GB");
-    assertEquals(qt.getSize(), 10);
+    assertEquals(10, qt.getSize());
-    assertEquals(qt.getUnit(), OzoneQuota.Units.GB);
+    assertEquals(OzoneQuota.Units.GB, qt.getUnit());
-    assertEquals(qt.sizeInBytes(), 10L * (1024L * 1024L * 1024L));
+    assertEquals(10L * (1024L * 1024L * 1024L), qt.sizeInBytes());
 
     qt = OzoneQuota.parseQuota("10BYTES");
-    assertEquals(qt.getSize(), 10);
+    assertEquals(10, qt.getSize());
-    assertEquals(qt.getUnit(), OzoneQuota.Units.BYTES);
+    assertEquals(OzoneQuota.Units.BYTES, qt.getUnit());
-    assertEquals(qt.sizeInBytes(), 10L);
+    assertEquals(10L, qt.sizeInBytes());
 
     OzoneQuota emptyQuota = new OzoneQuota();
-    assertEquals(emptyQuota.sizeInBytes(), -1L);
+    assertEquals(-1L, emptyQuota.sizeInBytes());
-    assertEquals(emptyQuota.getSize(), 0);
+    assertEquals(0, emptyQuota.getSize());
-    assertEquals(emptyQuota.getUnit(), OzoneQuota.Units.UNDEFINED);
+    assertEquals(OzoneQuota.Units.UNDEFINED, emptyQuota.getUnit());
   }
 
   @Test

hadoop-ozone/integration-test/src/test/java/org/apache/hadoop/hdds/scm/pipeline/TestPipelineClose.java

@@ -23,8 +23,7 @@
 import org.apache.hadoop.hdds.scm.container.ContainerID;
 import org.apache.hadoop.hdds.scm.container.ContainerInfo;
 import org.apache.hadoop.hdds.scm.container.ContainerManager;
-import org.apache.hadoop.hdds.scm.container.common.helpers
+import org.apache.hadoop.hdds.scm.container.common.helpers.ContainerWithPipeline;
-    .ContainerWithPipeline;
 import org.apache.hadoop.hdds.scm.server.StorageContainerManager;
 import org.apache.hadoop.ozone.MiniOzoneCluster;
 import org.junit.AfterClass;
@@ -36,11 +35,12 @@
 import java.util.Set;
 import java.util.concurrent.TimeoutException;
 
-import static org.apache.hadoop.hdds.protocol.proto.HddsProtos
+import static org.apache.hadoop.hdds.protocol.proto.HddsProtos.ReplicationFactor.THREE;
-    .ReplicationFactor.THREE;
+import static org.apache.hadoop.hdds.protocol.proto.HddsProtos.ReplicationType.RATIS;
-import static org.apache.hadoop.hdds.protocol.proto.HddsProtos
-    .ReplicationType.RATIS;
 
+/**
+ * Tests for Pipeline Closing.
+ */
 public class TestPipelineClose {
 
   private static MiniOzoneCluster cluster;
@@ -88,7 +88,6 @@ public static void shutdown() {
     }
   }
 
-
   @Test
   public void testPipelineCloseWithClosedContainer() throws IOException {
     Set<ContainerID> set = pipelineManager
@@ -112,8 +111,8 @@ public void testPipelineCloseWithClosedContainer() throws IOException {
     pipelineManager.finalizePipeline(ratisContainer1.getPipeline().getId());
     Pipeline pipeline1 = pipelineManager
         .getPipeline(ratisContainer1.getPipeline().getId());
-    Assert.assertEquals(pipeline1.getPipelineState(),
+    Assert.assertEquals(Pipeline.PipelineState.CLOSED,
-        Pipeline.PipelineState.CLOSED);
+        pipeline1.getPipelineState());
     pipelineManager.removePipeline(pipeline1.getId());
     for (DatanodeDetails dn : ratisContainer1.getPipeline().getNodes()) {
       // Assert that the pipeline has been removed from Node2PipelineMap as well
@@ -131,12 +130,12 @@ public void testPipelineCloseWithOpenContainer() throws IOException,
 
     ContainerID cId2 = ratisContainer2.getContainerInfo().containerID();
     pipelineManager.finalizePipeline(ratisContainer2.getPipeline().getId());
-    Assert.assertEquals(
+    Assert.assertEquals(Pipeline.PipelineState.CLOSED,
-        pipelineManager.getPipeline(ratisContainer2.getPipeline().getId())
+        pipelineManager.getPipeline(
-            .getPipelineState(), Pipeline.PipelineState.CLOSED);
+            ratisContainer2.getPipeline().getId()).getPipelineState());
     Pipeline pipeline2 = pipelineManager
         .getPipeline(ratisContainer2.getPipeline().getId());
-    Assert.assertEquals(pipeline2.getPipelineState(),
+    Assert.assertEquals(Pipeline.PipelineState.CLOSED,
-        Pipeline.PipelineState.CLOSED);
+        pipeline2.getPipelineState());
   }
 }

hadoop-ozone/integration-test/src/test/java/org/apache/hadoop/hdds/scm/pipeline/package-info.java

@@ -0,0 +1,22 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * <p>
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ */
+/**
+ * Package info tests.
+ */
+package org.apache.hadoop.hdds.scm.pipeline;

hadoop-ozone/integration-test/src/test/java/org/apache/hadoop/ozone/OzoneTestUtils.java

@@ -29,7 +29,15 @@
 import java.util.List;
 import java.util.function.Consumer;
 
-public class OzoneTestUtils {
+/**
+ * Helper class for Tests.
+ */
+public final class OzoneTestUtils {
+  /**
+   * Never Constructed.
+   */
+  private OzoneTestUtils() {
+  }
 
   /**
    * Close containers which contain the blocks listed in
@@ -55,7 +63,7 @@ public static boolean closeContainers(
             .getContainer(ContainerID.valueof(
                 blockID.getContainerID())).isOpen());
       } catch (IOException e) {
-        e.printStackTrace();
+        throw new AssertionError("Failed to close the container", e);
       }
     }, omKeyLocationInfoGroups);
   }

hadoop-ozone/integration-test/src/test/java/org/apache/hadoop/ozone/TestStorageContainerManagerHelper.java

@@ -40,12 +40,11 @@
 import org.apache.hadoop.ozone.web.utils.OzoneUtils;
 import org.apache.hadoop.utils.MetadataKeyFilters;
 import org.apache.hadoop.utils.MetadataKeyFilters.KeyPrefixFilter;
-import org.apache.hadoop.utils.MetadataKeyFilters.MetadataKeyFilter;
 import org.apache.hadoop.utils.MetadataStore;
 
 import java.io.IOException;
 import java.io.OutputStream;
-import java.util.LinkedList;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -83,8 +82,8 @@ public Map<String, OmKeyInfo> createKeys(int numOfKeys, int keySize)
     storageHandler.createVolume(createVolumeArgs);
 
     BucketArgs bucketArgs = new BucketArgs(bucket, createVolumeArgs);
-    bucketArgs.setAddAcls(new LinkedList<>());
+    bucketArgs.setAddAcls(new ArrayList<>());
-    bucketArgs.setRemoveAcls(new LinkedList<>());
+    bucketArgs.setRemoveAcls(new ArrayList<>());
     bucketArgs.setStorageType(StorageType.DISK);
     storageHandler.createBucket(bucketArgs);
 
@@ -144,9 +143,6 @@ public List<Long> getAllBlocks(Set<Long> containerIDs)
   public List<Long> getAllBlocks(Long containeID) throws IOException {
     List<Long> allBlocks = Lists.newArrayList();
     MetadataStore meta = getContainerMetadata(containeID);
-    MetadataKeyFilter filter =
-        (preKey, currentKey, nextKey) -> !DFSUtil.bytes2String(currentKey)
-            .startsWith(OzoneConsts.DELETING_KEY_PREFIX);
     List<Map.Entry<byte[], byte[]>> kvs =
         meta.getRangeKVs(null, Integer.MAX_VALUE,
             MetadataKeyFilters.getNormalKeyFilter());

hadoop-ozone/integration-test/src/test/java/org/apache/hadoop/ozone/client/rpc/TestCloseContainerHandlingByClient.java

@@ -61,6 +61,8 @@
 import static org.apache.hadoop.hdds.scm.ScmConfigKeys.HDDS_SCM_WATCHER_TIMEOUT;
 import static org.apache.hadoop.hdds.scm.ScmConfigKeys.OZONE_SCM_STALENODE_INTERVAL;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
+
 /**
  * Tests Close Container Exception handling by Ozone Client.
  */
@@ -121,7 +123,8 @@ public void testBlockWritesWithFlushAndClose() throws Exception {
     OzoneOutputStream key = createKey(keyName, ReplicationType.RATIS, 0);
     // write data more than 1 chunk
     byte[] data = ContainerTestHelper
-        .getFixedLengthString(keyString, chunkSize + chunkSize / 2).getBytes();
+        .getFixedLengthString(keyString, chunkSize + chunkSize / 2)
+        .getBytes(UTF_8);
     key.write(data);
 
     Assert.assertTrue(key.getOutputStream() instanceof ChunkGroupOutputStream);
@@ -141,9 +144,9 @@ public void testBlockWritesWithFlushAndClose() throws Exception {
     Assert.assertEquals(2 * data.length, keyInfo.getDataSize());
 
     // Written the same data twice
-    String dataString = new String(data);
+    String dataString = new String(data, UTF_8);
-    dataString.concat(dataString);
+    dataString = dataString.concat(dataString);
-    validateData(keyName, dataString.getBytes());
+    validateData(keyName, dataString.getBytes(UTF_8));
   }
 
   @Test
@@ -152,7 +155,8 @@ public void testBlockWritesCloseConsistency() throws Exception {
     OzoneOutputStream key = createKey(keyName, ReplicationType.RATIS, 0);
     // write data more than 1 chunk
     byte[] data = ContainerTestHelper
-        .getFixedLengthString(keyString, chunkSize + chunkSize / 2).getBytes();
+        .getFixedLengthString(keyString, chunkSize + chunkSize / 2)
+        .getBytes(UTF_8);
     key.write(data);
 
     Assert.assertTrue(key.getOutputStream() instanceof ChunkGroupOutputStream);
@@ -184,7 +188,7 @@ public void testMultiBlockWrites() throws Exception {
     // write data more than 1 chunk
     byte[] data =
         ContainerTestHelper.getFixedLengthString(keyString, (3 * blockSize))
-            .getBytes();
+            .getBytes(UTF_8);
     Assert.assertEquals(data.length, 3 * blockSize);
     key.write(data);
 
@@ -199,7 +203,7 @@ public void testMultiBlockWrites() throws Exception {
     // write 1 more block worth of data. It will fail and new block will be
     // allocated
     key.write(ContainerTestHelper.getFixedLengthString(keyString, blockSize)
-        .getBytes());
+        .getBytes(UTF_8));
 
     key.close();
     // read the key from OM again and match the length.The length will still
@@ -232,13 +236,13 @@ public void testMultiBlockWrites2() throws Exception {
     Assert.assertEquals(4, groupOutputStream.getStreamEntries().size());
     String dataString =
         ContainerTestHelper.getFixedLengthString(keyString, (2 * blockSize));
-    byte[] data = dataString.getBytes();
+    byte[] data = dataString.getBytes(UTF_8);
     key.write(data);
     // 3 block are completely written to the DataNode in 3 blocks.
     // Data of length half of chunkSize resides in the chunkOutput stream buffer
     String dataString2 =
         ContainerTestHelper.getFixedLengthString(keyString, chunkSize * 1 / 2);
-    key.write(dataString2.getBytes());
+    key.write(dataString2.getBytes(UTF_8));
     //get the name of a valid container
     OmKeyArgs keyArgs = new OmKeyArgs.Builder().setVolumeName(volumeName)
         .setBucketName(bucketName).setType(HddsProtos.ReplicationType.RATIS)
@@ -257,9 +261,9 @@ public void testMultiBlockWrites2() throws Exception {
     // closeContainerException and remaining data in the chunkOutputStream
     // buffer will be copied into a different allocated block and will be
     // committed.
-    Assert.assertEquals(dataString.concat(dataString2).getBytes().length,
+    Assert.assertEquals(dataString.concat(dataString2).getBytes(UTF_8).length,
         keyInfo.getDataSize());
-    validateData(keyName, dataString.concat(dataString2).getBytes());
+    validateData(keyName, dataString.concat(dataString2).getBytes(UTF_8));
   }
 
   @Test
@@ -274,7 +278,8 @@ public void testMultiBlockWrites3() throws Exception {
     Assert.assertEquals(4, groupOutputStream.getStreamEntries().size());
     // write data 3 blocks and one more chunk
     byte[] writtenData =
-        ContainerTestHelper.getFixedLengthString(keyString, keyLen).getBytes();
+        ContainerTestHelper.getFixedLengthString(keyString, keyLen)
+            .getBytes(UTF_8);
     byte[] data = Arrays.copyOfRange(writtenData, 0, 3 * blockSize + chunkSize);
     Assert.assertEquals(data.length, 3 * blockSize + chunkSize);
     key.write(data);
@@ -367,8 +372,8 @@ private void waitForContainerClose(HddsProtos.ReplicationType type,
           .isContainerPresent(cluster, containerID, dn))) {
         for (DatanodeDetails datanodeDetails : datanodes) {
           GenericTestUtils.waitFor(() -> ContainerTestHelper
-                  .isContainerClosed(cluster, containerID, datanodeDetails), 500,
+                  .isContainerClosed(cluster, containerID, datanodeDetails),
-              15 * 1000);
+              500, 15 * 1000);
           //double check if it's really closed
           // (waitFor also throws an exception)
           Assert.assertTrue(ContainerTestHelper
@@ -395,7 +400,7 @@ public void testDiscardPreallocatedBlocks() throws Exception {
     Assert.assertEquals(2, groupOutputStream.getStreamEntries().size());
     String dataString =
         ContainerTestHelper.getFixedLengthString(keyString, (1 * blockSize));
-    byte[] data = dataString.getBytes();
+    byte[] data = dataString.getBytes(UTF_8);
     key.write(data);
     List<OmKeyLocationInfo> locationInfos =
         new ArrayList<>(groupOutputStream.getLocationInfoList());
@@ -411,7 +416,7 @@ public void testDiscardPreallocatedBlocks() throws Exception {
     waitForContainerClose(keyName, key, HddsProtos.ReplicationType.RATIS);
     dataString =
         ContainerTestHelper.getFixedLengthString(keyString, (1 * blockSize));
-    data = dataString.getBytes();
+    data = dataString.getBytes(UTF_8);
     key.write(data);
     Assert.assertEquals(2, groupOutputStream.getStreamEntries().size());
 
@@ -443,7 +448,8 @@ public void testBlockWriteViaRatis() throws Exception {
     String keyName = "ratis";
     OzoneOutputStream key = createKey(keyName, ReplicationType.RATIS, 0);
     byte[] data = ContainerTestHelper
-        .getFixedLengthString(keyString, chunkSize + chunkSize / 2).getBytes();
+        .getFixedLengthString(keyString, chunkSize + chunkSize / 2)
+        .getBytes(UTF_8);
     key.write(data);
 
     //get the name of a valid container
@@ -462,9 +468,9 @@ public void testBlockWriteViaRatis() throws Exception {
     // updated correctly in OzoneManager once the steam is closed
     key.close();
     OmKeyInfo keyInfo = cluster.getOzoneManager().lookupKey(keyArgs);
-    String dataString = new String(data);
+    String dataString = new String(data, UTF_8);
-    dataString.concat(dataString);
+    dataString = dataString.concat(dataString);
     Assert.assertEquals(2 * data.length, keyInfo.getDataSize());
-    validateData(keyName, dataString.getBytes());
+    validateData(keyName, dataString.getBytes(UTF_8));
   }
 }

hadoop-ozone/integration-test/src/test/java/org/apache/hadoop/ozone/package-info.java

@@ -0,0 +1,22 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * <p>
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ */
+/**
+ * Test utils for Ozone.
+ */
+package org.apache.hadoop.ozone;

hadoop-ozone/integration-test/src/test/java/org/apache/hadoop/ozone/web/TestOzoneVolumes.java

@@ -23,6 +23,7 @@
 import org.apache.hadoop.ozone.TestOzoneHelper;
 import org.apache.log4j.Level;
 import org.apache.log4j.Logger;
+import org.junit.Ignore;
 import org.junit.Rule;
 import org.junit.BeforeClass;
 import org.junit.AfterClass;
@@ -158,6 +159,7 @@ public void testCreateVolumesInLoop() throws IOException {
    *
    * @throws IOException
    */
+  @Ignore("Test is ignored for time being, to be enabled after security.")
   public void testGetVolumesByUser() throws IOException {
     testGetVolumesByUser(port);
   }
@@ -167,6 +169,7 @@ public void testGetVolumesByUser() throws IOException {
    *
    * @throws IOException
    */
+  @Ignore("Test is ignored for time being, to be enabled after security.")
   public void testGetVolumesOfAnotherUser() throws IOException {
     super.testGetVolumesOfAnotherUser(port);
   }
@@ -177,6 +180,7 @@ public void testGetVolumesOfAnotherUser() throws IOException {
    *
    * @throws IOException
    */
+  @Ignore("Test is ignored for time being, to be enabled after security.")
   public void testGetVolumesOfAnotherUserShouldFail() throws IOException {
     super.testGetVolumesOfAnotherUserShouldFail(port);
   }

hadoop-ozone/integration-test/src/test/java/org/apache/hadoop/ozone/web/client/package-info.java

@@ -0,0 +1,22 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * <p>
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ */
+/**
+ * REST client tests.
+ */
+package org.apache.hadoop.ozone.web.client;

hadoop-ozone/integration-test/src/test/java/org/apache/hadoop/ozone/web/package-info.java

@@ -0,0 +1,22 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * <p>
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ */
+/**
+ * Rest Client Tests.
+ */
+package org.apache.hadoop.ozone.web;

hadoop-ozone/objectstore-service/src/main/java/org/apache/hadoop/ozone/web/handlers/BucketProcessTemplate.java

@@ -26,7 +26,7 @@
 import java.nio.file.DirectoryNotEmptyException;
 import java.nio.file.FileAlreadyExistsException;
 import java.nio.file.NoSuchFileException;
-import java.util.LinkedList;
+import java.util.ArrayList;
 import java.util.List;
 
 import org.apache.hadoop.hdds.protocol.StorageType;
@@ -211,7 +211,7 @@ List<String> getAcls(BucketArgs args, String tag)  {
         args.getHeaders().getRequestHeader(Header.OZONE_ACLS);
     List<String> filteredSet = null;
     if (aclStrings != null) {
-      filteredSet = new LinkedList<>();
+      filteredSet = new ArrayList<>();
       for (String s : aclStrings) {
         if (s.startsWith(tag)) {
           filteredSet.add(s.replaceFirst(tag, ""));

hadoop-ozone/objectstore-service/src/main/java/org/apache/hadoop/ozone/web/interfaces/StorageHandler.java

@@ -312,5 +312,6 @@ void renameKey(KeyArgs args, String toKeyName)
   /**
    * Closes all the opened resources.
    */
+  @Override
   void close();
 }

hadoop-ozone/objectstore-service/src/test/java/org/apache/hadoop/ozone/web/TestErrorCode.java

@@ -37,9 +37,9 @@ public void testErrorGen() {
     OzoneException e = ErrorTable
         .newError(ErrorTable.ACCESS_DENIED, getRequestID(), "/test/path",
                   "localhost");
-    assertEquals(e.getHostID(), "localhost");
+    assertEquals("localhost", e.getHostID());
-    assertEquals(e.getShortMessage(),
+    assertEquals(ErrorTable.ACCESS_DENIED.getShortMessage(),
-                 ErrorTable.ACCESS_DENIED.getShortMessage());
+        e.getShortMessage());
   }
 
   @Test

hadoop-ozone/objectstore-service/src/test/java/org/apache/hadoop/ozone/web/package-info.java

@@ -0,0 +1,22 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * <p>
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ */
+/**
+ * Tests the REST error codes.
+ */
+package org.apache.hadoop.ozone.web;

hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/om/BucketManagerImpl.java

@@ -257,6 +257,7 @@ private List<OzoneAcl> getUpdatedAclList(List<OzoneAcl> existingAcls,
    * @param bucketName - Name of the bucket.
    * @throws IOException - on Failure.
    */
+  @Override
   public void deleteBucket(String volumeName, String bucketName)
       throws IOException {
     Preconditions.checkNotNull(volumeName);

hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/om/OmMetadataManagerImpl.java

@@ -22,7 +22,6 @@
 import org.apache.commons.lang3.StringUtils;
 import org.apache.hadoop.hdds.client.BlockID;
 import org.apache.hadoop.hdds.conf.OzoneConfiguration;
-import org.apache.hadoop.hdds.server.ServerUtils;
 import org.apache.hadoop.hdfs.DFSUtil;
 import org.apache.hadoop.ozone.OmUtils;
 import org.apache.hadoop.ozone.OzoneConsts;
@@ -117,7 +116,7 @@ public class OmMetadataManagerImpl implements OMMetadataManager {
   public OmMetadataManagerImpl(OzoneConfiguration conf) throws IOException {
     File metaDir = OmUtils.getOmDbDir(conf);
     this.lock = new OzoneManagerLock(conf);
-    this.openKeyExpireThresholdMS = 1000 * conf.getInt(
+    this.openKeyExpireThresholdMS = 1000L * conf.getInt(
         OZONE_OPEN_KEY_EXPIRE_THRESHOLD_SECONDS,
         OZONE_OPEN_KEY_EXPIRE_THRESHOLD_SECONDS_DEFAULT);
 

hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/om/OzoneManager.java

@@ -989,6 +989,7 @@ public void setBucketProperty(OmBucketArgs args)
    * @param bucket - Name of the bucket.
    * @throws IOException
    */
+  @Override
   public void deleteBucket(String volume, String bucket) throws IOException {
     Map<String, String> auditMap = buildAuditMap(volume);
     auditMap.put(OzoneConsts.BUCKET, bucket);

hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/om/ServiceListJSONServlet.java

@@ -66,6 +66,7 @@ public class ServiceListJSONServlet  extends HttpServlet  {
 
   private transient OzoneManager om;
 
+  @Override
   public void init() throws ServletException {
     this.om = (OzoneManager) getServletContext()
         .getAttribute(OzoneConsts.OM_CONTEXT_ATTRIBUTE);

hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/om/VolumeManagerImpl.java

@@ -35,7 +35,7 @@
 import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
-import java.util.LinkedList;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 
@@ -73,7 +73,7 @@ private void addVolumeToOwnerList(String volume, String owner,
     // Get the volume list
     byte[] dbUserKey = metadataManager.getUserKey(owner);
     byte[] volumeList  = metadataManager.getUserTable().get(dbUserKey);
-    List<String> prevVolList = new LinkedList<>();
+    List<String> prevVolList = new ArrayList<>();
     if (volumeList != null) {
       VolumeList vlist = VolumeList.parseFrom(volumeList);
       prevVolList.addAll(vlist.getVolumeNamesList());
@@ -98,7 +98,7 @@ private void delVolumeFromOwnerList(String volume, String owner,
     // Get the volume list
     byte[] dbUserKey = metadataManager.getUserKey(owner);
     byte[] volumeList  = metadataManager.getUserTable().get(dbUserKey);
-    List<String> prevVolList = new LinkedList<>();
+    List<String> prevVolList = new ArrayList<>();
     if (volumeList != null) {
       VolumeList vlist = VolumeList.parseFrom(volumeList);
       prevVolList.addAll(vlist.getVolumeNamesList());
@@ -140,7 +140,7 @@ public void createVolume(OmVolumeArgs args) throws IOException {
 
       try(WriteBatch batch = new WriteBatch()) {
         // Write the vol info
-        List<HddsProtos.KeyValue> metadataList = new LinkedList<>();
+        List<HddsProtos.KeyValue> metadataList = new ArrayList<>();
         for (Map.Entry<String, String> entry :
             args.getKeyValueMap().entrySet()) {
           metadataList.add(HddsProtos.KeyValue.newBuilder()
@@ -250,6 +250,7 @@ public void setOwner(String volume, String owner) throws IOException {
    * @param quota - Quota in bytes.
    * @throws IOException
    */
+  @Override
   public void setQuota(String volume, long quota) throws IOException {
     Preconditions.checkNotNull(volume);
     metadataManager.getLock().acquireVolumeLock(volume);
@@ -293,6 +294,7 @@ public void setQuota(String volume, long quota) throws IOException {
    * @return VolumeArgs or exception is thrown.
    * @throws IOException
    */
+  @Override
   public OmVolumeArgs getVolumeInfo(String volume) throws IOException {
     Preconditions.checkNotNull(volume);
     metadataManager.getLock().acquireVolumeLock(volume);
@@ -384,6 +386,7 @@ public void deleteVolume(String volume) throws IOException {
    * @return true if the user has access for the volume, false otherwise
    * @throws IOException
    */
+  @Override
   public boolean checkVolumeAccess(String volume, OzoneAclInfo userAcl)
       throws IOException {
     Preconditions.checkNotNull(volume);

hadoop-ozone/ozone-manager/src/test/java/org/apache/hadoop/ozone/om/TestChunkStreams.java

@@ -30,6 +30,7 @@
 import java.io.IOException;
 import java.util.ArrayList;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.junit.Assert.assertEquals;
 
 /**
@@ -62,7 +63,7 @@ public void testWriteGroupOutputStream() throws Exception {
       assertEquals(0, groupOutputStream.getByteOffset());
 
       String dataString = RandomStringUtils.randomAscii(500);
-      byte[] data = dataString.getBytes();
+      byte[] data = dataString.getBytes(UTF_8);
       groupOutputStream.write(data, 0, data.length);
       assertEquals(500, groupOutputStream.getByteOffset());
 
@@ -95,7 +96,8 @@ public void testErrorWriteGroupOutputStream() throws Exception {
       assertEquals(0, groupOutputStream.getByteOffset());
 
       // first writes of 100 bytes should succeed
-      groupOutputStream.write(RandomStringUtils.randomAscii(100).getBytes());
+      groupOutputStream.write(RandomStringUtils.randomAscii(100)
+          .getBytes(UTF_8));
       assertEquals(100, groupOutputStream.getByteOffset());
 
       // second writes of 500 bytes should fail, as there should be only 400
@@ -104,7 +106,8 @@ public void testErrorWriteGroupOutputStream() throws Exception {
       // other add more informative error code rather than exception, need to
       // change this part.
       exception.expect(Exception.class);
-      groupOutputStream.write(RandomStringUtils.randomAscii(500).getBytes());
+      groupOutputStream.write(RandomStringUtils.randomAscii(500)
+          .getBytes(UTF_8));
       assertEquals(100, groupOutputStream.getByteOffset());
     }
   }
@@ -115,7 +118,7 @@ public void testReadGroupInputStream() throws Exception {
       ArrayList<ChunkInputStream> inputStreams = new ArrayList<>();
 
       String dataString = RandomStringUtils.randomAscii(500);
-      byte[] buf = dataString.getBytes();
+      byte[] buf = dataString.getBytes(UTF_8);
       int offset = 0;
       for (int i = 0; i < 5; i++) {
         int tempOffset = offset;
@@ -126,12 +129,12 @@ public void testReadGroupInputStream() throws Exception {
                   new ByteArrayInputStream(buf, tempOffset, 100);
 
               @Override
-              public void seek(long pos) throws IOException {
+              public synchronized void seek(long pos) throws IOException {
                 throw new UnsupportedOperationException();
               }
 
               @Override
-              public long getPos() throws IOException {
+              public synchronized long getPos() throws IOException {
                 return pos;
               }
 
@@ -142,12 +145,13 @@ public boolean seekToNewSource(long targetPos)
               }
 
               @Override
-              public int read() throws IOException {
+              public synchronized int read() throws IOException {
                 return in.read();
               }
 
               @Override
-              public int read(byte[] b, int off, int len) throws IOException {
+              public synchronized  int read(byte[] b, int off, int len)
+                  throws IOException {
                 int readLen = in.read(b, off, len);
                 pos += readLen;
                 return readLen;
@@ -162,7 +166,7 @@ public int read(byte[] b, int off, int len) throws IOException {
       int len = groupInputStream.read(resBuf, 0, 500);
 
       assertEquals(500, len);
-      assertEquals(dataString, new String(resBuf));
+      assertEquals(dataString, new String(resBuf, UTF_8));
     }
   }
 
@@ -172,7 +176,7 @@ public void testErrorReadGroupInputStream() throws Exception {
       ArrayList<ChunkInputStream> inputStreams = new ArrayList<>();
 
       String dataString = RandomStringUtils.randomAscii(500);
-      byte[] buf = dataString.getBytes();
+      byte[] buf = dataString.getBytes(UTF_8);
       int offset = 0;
       for (int i = 0; i < 5; i++) {
         int tempOffset = offset;
@@ -183,28 +187,29 @@ public void testErrorReadGroupInputStream() throws Exception {
                   new ByteArrayInputStream(buf, tempOffset, 100);
 
               @Override
-              public void seek(long pos) throws IOException {
+              public synchronized void seek(long pos) throws IOException {
                 throw new UnsupportedOperationException();
               }
 
               @Override
-              public long getPos() throws IOException {
+              public synchronized long getPos() throws IOException {
                 return pos;
               }
 
               @Override
-              public boolean seekToNewSource(long targetPos)
+              public synchronized boolean seekToNewSource(long targetPos)
                   throws IOException {
                 throw new UnsupportedOperationException();
               }
 
               @Override
-              public int read() throws IOException {
+              public synchronized int read() throws IOException {
                 return in.read();
               }
 
               @Override
-              public int read(byte[] b, int off, int len) throws IOException {
+              public synchronized int read(byte[] b, int off, int len)
+                  throws IOException {
                 int readLen = in.read(b, off, len);
                 pos += readLen;
                 return readLen;
@@ -222,14 +227,14 @@ public int read(byte[] b, int off, int len) throws IOException {
       assertEquals(60, groupInputStream.getRemainingOfIndex(3));
       assertEquals(340, len);
       assertEquals(dataString.substring(0, 340),
-          new String(resBuf).substring(0, 340));
+          new String(resBuf, UTF_8).substring(0, 340));
 
       // read following 300 bytes, but only 200 left
       len = groupInputStream.read(resBuf, 340, 260);
       assertEquals(4, groupInputStream.getCurrentStreamIndex());
       assertEquals(0, groupInputStream.getRemainingOfIndex(4));
       assertEquals(160, len);
-      assertEquals(dataString, new String(resBuf).substring(0, 500));
+      assertEquals(dataString, new String(resBuf, UTF_8).substring(0, 500));
 
       // further read should get EOF
       len = groupInputStream.read(resBuf, 0, 1);

hadoop-ozone/ozone-manager/src/test/java/org/apache/hadoop/ozone/om/TestKeyManagerImpl.java

@@ -18,7 +18,6 @@
 
 package org.apache.hadoop.ozone.om;
 
-import java.nio.charset.StandardCharsets;
 import java.util.Arrays;
 import java.util.HashSet;
 import java.util.Set;
@@ -49,6 +48,8 @@
 import org.rocksdb.Statistics;
 import org.rocksdb.StatsLevel;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
+
 /**
  * Test class for @{@link KeyManagerImpl}.
  * */
@@ -93,11 +94,11 @@ private void setupMocks() throws Exception {
     Mockito.when(metadataManager.getLock())
         .thenReturn(new OzoneManagerLock(conf));
     Mockito.when(metadataManager.getVolumeKey(VOLUME_NAME))
-        .thenReturn(VOLUME_NAME.getBytes());
+        .thenReturn(VOLUME_NAME.getBytes(UTF_8));
     Mockito.when(metadataManager.getBucketKey(VOLUME_NAME, BUCKET_NAME))
-        .thenReturn(BUCKET_NAME.getBytes());
+        .thenReturn(BUCKET_NAME.getBytes(UTF_8));
     Mockito.when(metadataManager.getOpenKeyBytes(VOLUME_NAME, BUCKET_NAME,
-        KEY_NAME, 1)).thenReturn(KEY_NAME.getBytes());
+        KEY_NAME, 1)).thenReturn(KEY_NAME.getBytes(UTF_8));
   }
 
   private void setupRocksDb() throws Exception {
@@ -129,11 +130,11 @@ private void setupRocksDb() throws Exception {
 
     rdbStore = new RDBStore(folder.newFolder(), options, configSet);
     rdbTable = rdbStore.getTable("testTable");
-    rdbTable.put(VOLUME_NAME.getBytes(),
+    rdbTable.put(VOLUME_NAME.getBytes(UTF_8),
-        RandomStringUtils.random(10).getBytes(StandardCharsets.UTF_8));
+        RandomStringUtils.random(10).getBytes(UTF_8));
-    rdbTable.put(BUCKET_NAME.getBytes(),
+    rdbTable.put(BUCKET_NAME.getBytes(UTF_8),
-        RandomStringUtils.random(10).getBytes(StandardCharsets.UTF_8));
+        RandomStringUtils.random(10).getBytes(UTF_8));
-    rdbTable.put(KEY_NAME.getBytes(), keyData.toByteArray());
+    rdbTable.put(KEY_NAME.getBytes(UTF_8), keyData.toByteArray());
   }
 
   @Test

hadoop-ozone/ozonefs/src/main/java/org/apache/hadoop/fs/ozone/OzoneFileSystem.java

@@ -252,6 +252,7 @@ private class RenameIterator extends OzoneListingIterator {
       LOG.trace("rename from:{} to:{}", srcKey, dstKey);
     }
 
+    @Override
     boolean processKey(String key) throws IOException {
       String newKeyName = dstKey.concat(key.substring(srcKey.length()));
       bucket.renameKey(key, newKeyName);
@@ -370,6 +371,7 @@ && listStatus(f).length != 0) {
       }
     }
 
+    @Override
     boolean processKey(String key) throws IOException {
       if (key.equals("")) {
         LOG.trace("Skipping deleting root directory");
@@ -496,6 +498,7 @@ private class ListStatusIterator extends OzoneListingIterator {
      * @return always returns true
      * @throws IOException
      */
+    @Override
     boolean processKey(String key) throws IOException {
       Path keyPath = new Path(OZONE_URI_DELIMITER + key);
       if (key.equals(getPathKey())) {

hadoop-ozone/ozonefs/src/test/java/org/apache/hadoop/fs/ozone/TestOzoneFileInterfaces.java

@@ -51,6 +51,7 @@
 import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.util.Time;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.apache.hadoop.fs.ozone.Constants.OZONE_DEFAULT_USER;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
@@ -176,7 +177,7 @@ public void testOzFsReadWrite() throws IOException {
       byte[] buffer = new byte[stringLen];
       // This read will not change the offset inside the file
       int readBytes = inputStream.read(0, buffer, 0, buffer.length);
-      String out = new String(buffer, 0, buffer.length);
+      String out = new String(buffer, 0, buffer.length, UTF_8);
       assertEquals(data, out);
       assertEquals(readBytes, buffer.length);
       assertEquals(0, inputStream.getPos());

hadoop-ozone/ozonefs/src/test/java/org/apache/hadoop/fs/ozone/package-info.java

@@ -0,0 +1,22 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * <p>
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ */
+/**
+ * Ozone FS Contract tests.
+ */
+package org.apache.hadoop.fs.ozone;

hadoop-ozone/s3gateway/src/main/java/org/apache/hadoop/ozone/s3/header/AuthorizationHeaderV2.java

@@ -49,6 +49,7 @@ public AuthorizationHeaderV2(String auth) throws OS3Exception {
    *
    * @throws OS3Exception
    */
+  @SuppressWarnings("StringSplitter")
   public void parseHeader() throws OS3Exception {
     String[] split = authHeader.split(" ");
     if (split.length != 2) {

hadoop-ozone/s3gateway/src/main/java/org/apache/hadoop/ozone/s3/header/AuthorizationHeaderV4.java

@@ -60,6 +60,7 @@ public AuthorizationHeaderV4(String header) throws OS3Exception {
    * Signature=db81b057718d7c1b3b8dffa29933099551c51d787b3b13b9e0f9ebed45982bf2
    * @throws OS3Exception
    */
+  @SuppressWarnings("StringSplitter")
   public void parseAuthHeader() throws OS3Exception {
     String[] split = authHeader.split(" ");
 

hadoop-ozone/s3gateway/src/main/java/org/apache/hadoop/ozone/s3/header/Credential.java

@@ -54,6 +54,7 @@ public class Credential {
    *
    * @throws OS3Exception
    */
+  @SuppressWarnings("StringSplitter")
   public void parseCredential() throws OS3Exception {
     String[] split = credential.split("/");
     if (split.length == 5) {

hadoop-ozone/s3gateway/src/test/java/org/apache/hadoop/ozone/client/ObjectStoreStub.java

@@ -209,6 +209,7 @@ public String getOzoneBucketMapping(String s3BucketName) throws IOException {
   }
 
   @Override
+  @SuppressWarnings("StringSplitter")
   public String getOzoneVolumeName(String s3BucketName) throws IOException {
     if (bucketVolumeMap.get(s3BucketName) == null) {
       throw new IOException("S3_BUCKET_NOT_FOUND");
@@ -217,6 +218,7 @@ public String getOzoneVolumeName(String s3BucketName) throws IOException {
   }
 
   @Override
+  @SuppressWarnings("StringSplitter")
   public String getOzoneBucketName(String s3BucketName) throws IOException {
     if (bucketVolumeMap.get(s3BucketName) == null) {
       throw new IOException("S3_BUCKET_NOT_FOUND");

hadoop-ozone/s3gateway/src/test/java/org/apache/hadoop/ozone/s3/endpoint/TestBucketDelete.java

@@ -63,7 +63,7 @@ public void setup() throws Exception {
   @Test
   public void testBucketEndpoint() throws Exception {
     Response response = bucketEndpoint.delete(bucketName);
-    assertEquals(response.getStatus(), HttpStatus.SC_NO_CONTENT);
+    assertEquals(HttpStatus.SC_NO_CONTENT, response.getStatus());
 
   }
 

hadoop-ozone/s3gateway/src/test/java/org/apache/hadoop/ozone/s3/endpoint/TestMultiDeleteRequestUnmarshaller.java

@@ -23,6 +23,8 @@
 import java.io.IOException;
 
 import org.junit.Assert;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.junit.Assert.*;
 import org.junit.Test;
 
@@ -40,7 +42,7 @@ public void fromStreamWithNamespace() throws IOException {
                 + ".com/doc/2006-03-01/\"><Object>key1</Object><Object>key2"
                 + "</Object><Object>key3"
                 + "</Object></Delete>")
-                .getBytes());
+                .getBytes(UTF_8));
 
     //WHEN
     MultiDeleteRequest multiDeleteRequest =
@@ -58,7 +60,7 @@ public void fromStreamWithoutNamespace() throws IOException {
             ("<Delete><Object>key1</Object><Object>key2"
                 + "</Object><Object>key3"
                 + "</Object></Delete>")
-                .getBytes());
+                .getBytes(UTF_8));
 
     //WHEN
     MultiDeleteRequest multiDeleteRequest =

hadoop-ozone/s3gateway/src/test/java/org/apache/hadoop/ozone/s3/endpoint/TestObjectGet.java

@@ -37,6 +37,8 @@
 import org.junit.Test;
 import org.mockito.Mockito;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
+
 /**
  * Test get object.
  */
@@ -54,15 +56,16 @@ public void get() throws IOException, OS3Exception {
     OzoneBucket bucket =
         volume.getBucket("b1");
     OzoneOutputStream keyStream =
-        bucket.createKey("key1", CONTENT.getBytes().length);
+        bucket.createKey("key1", CONTENT.getBytes(UTF_8).length);
-    keyStream.write(CONTENT.getBytes());
+    keyStream.write(CONTENT.getBytes(UTF_8));
     keyStream.close();
 
     ObjectEndpoint rest = new ObjectEndpoint();
     rest.setClient(client);
     HttpHeaders headers = Mockito.mock(HttpHeaders.class);
     rest.setHeaders(headers);
-    ByteArrayInputStream body = new ByteArrayInputStream(CONTENT.getBytes());
+    ByteArrayInputStream body =
+        new ByteArrayInputStream(CONTENT.getBytes(UTF_8));
 
     //WHEN
     rest.get("b1", "key1", body);

hadoop-ozone/s3gateway/src/test/java/org/apache/hadoop/ozone/s3/endpoint/TestObjectHead.java

@@ -32,6 +32,7 @@
 import org.apache.hadoop.ozone.s3.exception.OS3Exception;
 
 import static java.net.HttpURLConnection.HTTP_NOT_FOUND;
+import static java.nio.charset.StandardCharsets.UTF_8;
 import org.apache.commons.lang3.RandomStringUtils;
 import org.junit.Assert;
 import org.junit.Before;
@@ -69,9 +70,9 @@ public void testHeadObject() throws Exception {
     //GIVEN
     String value = RandomStringUtils.randomAlphanumeric(32);
     OzoneOutputStream out = bucket.createKey("key1",
-        value.getBytes().length, ReplicationType.STAND_ALONE,
+        value.getBytes(UTF_8).length, ReplicationType.STAND_ALONE,
         ReplicationFactor.ONE);
-    out.write(value.getBytes());
+    out.write(value.getBytes(UTF_8));
     out.close();
 
     //WHEN
@@ -79,7 +80,7 @@ public void testHeadObject() throws Exception {
 
     //THEN
     Assert.assertEquals(200, response.getStatus());
-    Assert.assertEquals(value.getBytes().length,
+    Assert.assertEquals(value.getBytes(UTF_8).length,
         Long.parseLong(response.getHeaderString("Content-Length")));
 
     DateTimeFormatter.RFC_1123_DATE_TIME
@@ -91,7 +92,8 @@ public void testHeadObject() throws Exception {
   public void testHeadFailByBadName() throws Exception {
     //Head an object that doesn't exist.
     try {
-      keyEndpoint.head(bucketName, "badKeyName");
+      Response response =  keyEndpoint.head(bucketName, "badKeyName");
+      Assert.assertEquals(404, response.getStatus());
     } catch (OS3Exception ex) {
       Assert.assertTrue(ex.getCode().contains("NoSuchObject"));
       Assert.assertTrue(ex.getErrorMessage().contains("object does not exist"));

hadoop-ozone/tools/src/main/java/org/apache/hadoop/ozone/freon/RandomKeyGenerator.java

@@ -286,7 +286,7 @@ private Thread getProgressBarThread() {
     long maxValue;
 
     currentValue = () -> numberOfKeysAdded.get();
-    maxValue = numOfVolumes *
+    maxValue = (long) numOfVolumes *
         numOfBuckets *
         numOfKeys;
 

hadoop-ozone/tools/src/test/java/org/apache/hadoop/ozone/freon/TestFreonWithDatanodeFastRestart.java

@@ -88,8 +88,8 @@ public void testRestart() throws Exception {
     String expectedSnapFile =
         storage.getSnapshotFile(termIndexBeforeRestart.getTerm(),
             termIndexBeforeRestart.getIndex()).getAbsolutePath();
-    Assert.assertEquals(snapshotInfo.getFile().getPath().toString(),
+    Assert.assertEquals(expectedSnapFile,
-        expectedSnapFile);
+        snapshotInfo.getFile().getPath().toString());
     Assert.assertEquals(termInSnapshot, termIndexBeforeRestart);
 
     // After restart the term index might have progressed to apply pending

hadoop-ozone/tools/src/test/java/org/apache/hadoop/ozone/freon/package-info.java

@@ -0,0 +1,22 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * <p>
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ */
+/**
+ * Freon Ozone Load Generator.
+ */
+package org.apache.hadoop.ozone.freon;

hadoop-ozone/tools/src/test/java/org/apache/hadoop/ozone/om/TestOmSQLCli.java

@@ -45,10 +45,10 @@
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Statement;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.HashMap;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.UUID;
 
@@ -182,7 +182,7 @@ public void testOmDB() throws Exception {
     String sql = "SELECT * FROM volumeList";
     ResultSet rs = executeQuery(conn, sql);
     List<String> expectedValues =
-        new LinkedList<>(Arrays.asList(volumeName0, volumeName1));
+        new ArrayList<>(Arrays.asList(volumeName0, volumeName1));
     while (rs.next()) {
       String userNameRs = rs.getString("userName");
       String volumeNameRs = rs.getString("volumeName");
@@ -194,7 +194,7 @@ public void testOmDB() throws Exception {
     sql = "SELECT * FROM volumeInfo";
     rs = executeQuery(conn, sql);
     expectedValues =
-        new LinkedList<>(Arrays.asList(volumeName0, volumeName1));
+        new ArrayList<>(Arrays.asList(volumeName0, volumeName1));
     while (rs.next()) {
       String adName = rs.getString("adminName");
       String ownerName = rs.getString("ownerName");
@@ -208,7 +208,7 @@ public void testOmDB() throws Exception {
     sql = "SELECT * FROM aclInfo";
     rs = executeQuery(conn, sql);
     expectedValues =
-        new LinkedList<>(Arrays.asList(volumeName0, volumeName1));
+        new ArrayList<>(Arrays.asList(volumeName0, volumeName1));
     while (rs.next()) {
       String adName = rs.getString("adminName");
       String ownerName = rs.getString("ownerName");

hadoop-ozone/tools/src/test/java/org/apache/hadoop/ozone/om/package-info.java

@@ -0,0 +1,22 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * <p>
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ */
+/**
+ * OM to SQL Converter. Currently broken.
+ */
+package org.apache.hadoop.ozone.om;