diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/HostRestrictingAuthorizationFilterHandler.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/HostRestrictingAuthorizationFilterHandler.java
index 8c5d538d23..c76d934691 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/HostRestrictingAuthorizationFilterHandler.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/HostRestrictingAuthorizationFilterHandler.java
@@ -43,8 +43,8 @@
 import java.util.List;
 import java.util.Map;
 
-import static io.netty.handler.codec.http.HttpHeaders.Names.CONNECTION;
-import static io.netty.handler.codec.http.HttpHeaders.Values.CLOSE;
+import static io.netty.handler.codec.http.HttpHeaderNames.CONNECTION;
+import static io.netty.handler.codec.http.HttpHeaderValues.CLOSE;
 import static io.netty.handler.codec.http.HttpResponseStatus.INTERNAL_SERVER_ERROR;
 import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;
 
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/RestCsrfPreventionFilterHandler.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/RestCsrfPreventionFilterHandler.java
index a2c2d37043..4e3c2d1ae7 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/RestCsrfPreventionFilterHandler.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/RestCsrfPreventionFilterHandler.java
@@ -17,8 +17,8 @@
  */
 package org.apache.hadoop.hdfs.server.datanode.web;
 
-import static io.netty.handler.codec.http.HttpHeaders.Names.CONNECTION;
-import static io.netty.handler.codec.http.HttpHeaders.Values.CLOSE;
+import static io.netty.handler.codec.http.HttpHeaderNames.CONNECTION;
+import static io.netty.handler.codec.http.HttpHeaderValues.CLOSE;
 import static io.netty.handler.codec.http.HttpResponseStatus.INTERNAL_SERVER_ERROR;
 import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;
 import static org.apache.hadoop.hdfs.client.HdfsClientConfigKeys.DFS_WEBHDFS_REST_CSRF_ENABLED_DEFAULT;
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/SimpleHttpProxyHandler.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/SimpleHttpProxyHandler.java
index 51aeab024b..ef8d90a4c4 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/SimpleHttpProxyHandler.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/SimpleHttpProxyHandler.java
@@ -34,12 +34,12 @@
 import io.netty.handler.codec.http.HttpRequest;
 import io.netty.handler.codec.http.HttpRequestEncoder;
 import io.netty.handler.codec.http.HttpResponseEncoder;
+import io.netty.handler.codec.http.HttpHeaderValues;
 import org.slf4j.Logger;
 
 import java.net.InetSocketAddress;
 
-import static io.netty.handler.codec.http.HttpHeaders.Names.CONNECTION;
-import static io.netty.handler.codec.http.HttpHeaders.Values;
+import static io.netty.handler.codec.http.HttpHeaderNames.CONNECTION;
 import static io.netty.handler.codec.http.HttpResponseStatus.INTERNAL_SERVER_ERROR;
 import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;
 
@@ -119,12 +119,12 @@ public void operationComplete(ChannelFuture future) throws Exception {
           ctx.channel().pipeline().remove(HttpResponseEncoder.class);
           HttpRequest newReq = new DefaultFullHttpRequest(HTTP_1_1, req.method(), req.uri());
           newReq.headers().add(req.headers());
-          newReq.headers().set(CONNECTION, Values.CLOSE);
+          newReq.headers().set(CONNECTION, HttpHeaderValues.CLOSE);
           future.channel().writeAndFlush(newReq);
         } else {
           DefaultHttpResponse resp = new DefaultHttpResponse(HTTP_1_1,
             INTERNAL_SERVER_ERROR);
-          resp.headers().set(CONNECTION, Values.CLOSE);
+          resp.headers().set(CONNECTION, HttpHeaderValues.CLOSE);
           LOG.info("Proxy " + uri + " failed. Cause: ", future.cause());
           ctx.writeAndFlush(resp).addListener(ChannelFutureListener.CLOSE);
           client.close();
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/webhdfs/ExceptionHandler.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/webhdfs/ExceptionHandler.java
index 02ec25c13c..6fe0851bb3 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/webhdfs/ExceptionHandler.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/webhdfs/ExceptionHandler.java
@@ -33,8 +33,8 @@
 import java.io.FileNotFoundException;
 import java.io.IOException;
 
-import static io.netty.handler.codec.http.HttpHeaders.Names.CONTENT_LENGTH;
-import static io.netty.handler.codec.http.HttpHeaders.Names.CONTENT_TYPE;
+import static io.netty.handler.codec.http.HttpHeaderNames.CONTENT_LENGTH;
+import static io.netty.handler.codec.http.HttpHeaderNames.CONTENT_TYPE;
 import static io.netty.handler.codec.http.HttpResponseStatus.BAD_REQUEST;
 import static io.netty.handler.codec.http.HttpResponseStatus.FORBIDDEN;
 import static io.netty.handler.codec.http.HttpResponseStatus.INTERNAL_SERVER_ERROR;
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/webhdfs/HdfsWriter.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/webhdfs/HdfsWriter.java
index 3d928ff3ee..f01479a9b9 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/webhdfs/HdfsWriter.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/webhdfs/HdfsWriter.java
@@ -30,8 +30,8 @@
 import java.io.IOException;
 import java.io.OutputStream;
 
-import static io.netty.handler.codec.http.HttpHeaders.Names.CONNECTION;
-import static io.netty.handler.codec.http.HttpHeaders.Values.CLOSE;
+import static io.netty.handler.codec.http.HttpHeaderNames.CONNECTION;
+import static io.netty.handler.codec.http.HttpHeaderValues.CLOSE;
 
 class HdfsWriter extends SimpleChannelInboundHandler<HttpContent> {
   private final DFSClient client;
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/webhdfs/WebHdfsHandler.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/webhdfs/WebHdfsHandler.java
index 7567162840..8de736ac0e 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/webhdfs/WebHdfsHandler.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/webhdfs/WebHdfsHandler.java
@@ -62,17 +62,17 @@
 import java.security.PrivilegedExceptionAction;
 import java.util.EnumSet;
 
-import static io.netty.handler.codec.http.HttpHeaders.Names.ACCEPT;
-import static io.netty.handler.codec.http.HttpHeaders.Names.ACCESS_CONTROL_ALLOW_HEADERS;
-import static io.netty.handler.codec.http.HttpHeaders.Names.ACCESS_CONTROL_ALLOW_METHODS;
-import static io.netty.handler.codec.http.HttpHeaders.Names.ACCESS_CONTROL_ALLOW_ORIGIN;
-import static io.netty.handler.codec.http.HttpHeaders.Names.ACCESS_CONTROL_MAX_AGE;
-import static io.netty.handler.codec.http.HttpHeaders.Names.CONNECTION;
-import static io.netty.handler.codec.http.HttpHeaders.Names.CONTENT_LENGTH;
-import static io.netty.handler.codec.http.HttpHeaders.Names.CONTENT_TYPE;
-import static io.netty.handler.codec.http.HttpHeaders.Names.LOCATION;
-import static io.netty.handler.codec.http.HttpHeaders.Values.CLOSE;
-import static io.netty.handler.codec.http.HttpHeaders.Values.KEEP_ALIVE;
+import static io.netty.handler.codec.http.HttpHeaderNames.ACCEPT;
+import static io.netty.handler.codec.http.HttpHeaderNames.ACCESS_CONTROL_ALLOW_HEADERS;
+import static io.netty.handler.codec.http.HttpHeaderNames.ACCESS_CONTROL_ALLOW_METHODS;
+import static io.netty.handler.codec.http.HttpHeaderNames.ACCESS_CONTROL_ALLOW_ORIGIN;
+import static io.netty.handler.codec.http.HttpHeaderNames.ACCESS_CONTROL_MAX_AGE;
+import static io.netty.handler.codec.http.HttpHeaderNames.CONNECTION;
+import static io.netty.handler.codec.http.HttpHeaderNames.CONTENT_LENGTH;
+import static io.netty.handler.codec.http.HttpHeaderNames.CONTENT_TYPE;
+import static io.netty.handler.codec.http.HttpHeaderNames.LOCATION;
+import static io.netty.handler.codec.http.HttpHeaderValues.CLOSE;
+import static io.netty.handler.codec.http.HttpHeaderValues.KEEP_ALIVE;
 import static io.netty.handler.codec.http.HttpMethod.GET;
 import static io.netty.handler.codec.http.HttpMethod.OPTIONS;
 import static io.netty.handler.codec.http.HttpMethod.POST;
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/FSImageHandler.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/FSImageHandler.java
index bfa35aaf1e..963406771b 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/FSImageHandler.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/FSImageHandler.java
@@ -40,10 +40,10 @@
 import java.util.List;
 import java.util.Map;
 
-import static io.netty.handler.codec.http.HttpHeaders.Names.CONNECTION;
-import static io.netty.handler.codec.http.HttpHeaders.Names.CONTENT_LENGTH;
-import static io.netty.handler.codec.http.HttpHeaders.Names.CONTENT_TYPE;
-import static io.netty.handler.codec.http.HttpHeaders.Values.CLOSE;
+import static io.netty.handler.codec.http.HttpHeaderNames.CONNECTION;
+import static io.netty.handler.codec.http.HttpHeaderNames.CONTENT_LENGTH;
+import static io.netty.handler.codec.http.HttpHeaderNames.CONTENT_TYPE;
+import static io.netty.handler.codec.http.HttpHeaderValues.CLOSE;
 import static io.netty.handler.codec.http.HttpResponseStatus.BAD_REQUEST;
 import static io.netty.handler.codec.http.HttpResponseStatus.FORBIDDEN;
 import static io.netty.handler.codec.http.HttpResponseStatus.INTERNAL_SERVER_ERROR;
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/web/TestDatanodeHttpXFrame.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/web/TestDatanodeHttpXFrame.java
index 62827a2e5d..b6ad5a9a5d 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/web/TestDatanodeHttpXFrame.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/web/TestDatanodeHttpXFrame.java
@@ -57,8 +57,7 @@ public void testDataNodeXFrameOptionsEnabled() throws Exception {
     cluster = createCluster(xFrameEnabled, null);
     HttpURLConnection conn = getConn(cluster);
     String xfoHeader = conn.getHeaderField("X-FRAME-OPTIONS");
-    Assert.assertTrue("X-FRAME-OPTIONS is absent in the header",
-        xfoHeader != null);
+    Assert.assertNotNull("X-FRAME-OPTIONS is absent in the header", xfoHeader);
     Assert.assertTrue(xfoHeader.endsWith(HttpServer2.XFrameOption
         .SAMEORIGIN.toString()));
   }
@@ -69,7 +68,7 @@ public void testNameNodeXFrameOptionsDisabled() throws Exception {
     cluster = createCluster(xFrameEnabled, null);
     HttpURLConnection conn = getConn(cluster);
     String xfoHeader = conn.getHeaderField("X-FRAME-OPTIONS");
-    Assert.assertTrue("unexpected X-FRAME-OPTION in header", xfoHeader == null);
+    Assert.assertNull("unexpected X-FRAME-OPTION in header", xfoHeader);
   }
 
   @Test