HADOOP-11212. NetUtils.wrapException to handle SocketException explicitly. (Contributed by Steve Loughran)

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/net/NetUtils.java

@@ -782,6 +782,15 @@ public static IOException wrapException(final String destHost,
               + ": " + exception
               + ";"
               + see("EOFException"));
+    } else if (exception instanceof SocketException) {
+      // Many of the predecessor exceptions are subclasses of SocketException,
+      // so must be handled before this
+      return wrapWithMessage(exception,
+          "Call From "
+              + localHost + " to " + destHost + ":" + destPort
+              + " failed on socket exception: " + exception
+              + ";"
+              + see("SocketException"));
     }
     else {
       return (IOException) new IOException("Failed on local exception: "

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/net/TestNetUtils.java

@@ -72,7 +72,7 @@ public class TestNetUtils {
    * This is a regression test for HADOOP-6722.
    */
   @Test
-  public void testAvoidLoopbackTcpSockets() throws Exception {
+  public void testAvoidLoopbackTcpSockets() throws Throwable {
     Configuration conf = new Configuration();
 
     Socket socket = NetUtils.getDefaultSocketFactory(conf)
@@ -88,11 +88,11 @@ public void testAvoidLoopbackTcpSockets() throws Exception {
       fail("Should not have connected");
     } catch (ConnectException ce) {
       System.err.println("Got exception: " + ce);
-      assertTrue(ce.getMessage().contains("resulted in a loopback"));
+      assertInException(ce, "resulted in a loopback");
     } catch (SocketException se) {
       // Some TCP stacks will actually throw their own Invalid argument exception
       // here. This is also OK.
-      assertTrue(se.getMessage().contains("Invalid argument"));
+      assertInException(se, "Invalid argument");
     }
   }
   
@@ -188,13 +188,9 @@ public void testVerifyHostnamesException() throws UnknownHostException {
   }  
 
   @Test
-  public void testVerifyHostnamesNoException() {
+  public void testVerifyHostnamesNoException() throws UnknownHostException {
     String[] names = {"valid.host.com", "1.com"};
-    try {
     NetUtils.verifyHostnames(names);
-    } catch (UnknownHostException e) {
-      fail("NetUtils.verifyHostnames threw unexpected UnknownHostException");
-    }
   }
 
   /** 
@@ -268,6 +264,17 @@ public void testWrapEOFException() throws Throwable {
     assertInException(wrapped, "/EOFException");
   }
 
+  @Test
+  public void testWrapSocketException() throws Throwable {
+    IOException wrapped = verifyExceptionClass(new SocketException("failed"),
+        SocketException.class);
+    assertInException(wrapped, "failed");
+    assertWikified(wrapped);
+    assertInException(wrapped, "localhost");
+    assertRemoteDetailsIncluded(wrapped);
+    assertInException(wrapped, "/SocketException");
+  }
+
   @Test
   public void testGetConnectAddress() throws IOException {
     NetUtils.addStaticResolution("host", "127.0.0.1");
@@ -353,10 +360,8 @@ private IOException verifyExceptionClass(IOException e,
                                            Class expectedClass)
       throws Throwable {
     assertNotNull("Null Exception", e);
-    IOException wrapped =
+    IOException wrapped = NetUtils.wrapException("desthost", DEST_PORT,
-        NetUtils.wrapException("desthost", DEST_PORT,
+         "localhost", LOCAL_PORT, e);
-                               "localhost", LOCAL_PORT,
-                               e);
     LOG.info(wrapped.toString(), wrapped);
     if(!(wrapped.getClass().equals(expectedClass))) {
       throw new AssertionFailedError("Wrong exception class; expected "