HADOOP-15178. Generalize NetUtils#wrapException to handle other subclasses with String Constructor. Contributed by Ajay Kumar.

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

@@ -715,9 +715,9 @@ public class NetUtils {
    * return an IOException with the input exception as the cause and also
    * include the host details. The new exception provides the stack trace of the
    * place where the exception is thrown and some extra diagnostics information.
-   * If the exception is BindException or ConnectException or
-   * UnknownHostException or SocketTimeoutException, return a new one of the
-   * same type; Otherwise return an IOException.
+   * If the exception is of type BindException, ConnectException,
+   * UnknownHostException, SocketTimeoutException or has a String constructor,
+   * return a new one of the same type; Otherwise return an IOException.
    *
    * @param destHost target host (nullable)
    * @param destPort target port
@@ -731,6 +731,7 @@ public class NetUtils {
                                           final String localHost,
                                           final int localPort,
                                           final IOException exception) {
+    try {
       if (exception instanceof BindException) {
         return wrapWithMessage(exception,
             "Problem binding to ["
@@ -800,14 +801,20 @@ public class NetUtils {
                 + " failed on socket exception: " + exception
                 + ";"
                 + see("SocketException"));
+      } else {
+        // Return instance of same type if Exception has a String constructor
+        return wrapWithMessage(exception,
+            "DestHost:destPort " + destHost + ":" + destPort
+                + " , LocalHost:localPort " + localHost
+                + ":" + localPort + ". Failed on local exception: " +
+                exception);
+
       }
-    else {
+    } catch (IOException ex) {
       return (IOException) new IOException("Failed on local exception: "
-             + exception
-             + "; Host Details : "
+          + exception + "; Host Details : "
           + getHostDetailsAsString(destHost, destPort, localHost))
           .initCause(exception);
-
     }
   }
 
@@ -817,16 +824,16 @@ public class NetUtils {
   
   @SuppressWarnings("unchecked")
   private static <T extends IOException> T wrapWithMessage(
-      T exception, String msg) {
+      T exception, String msg) throws T {
     Class<? extends Throwable> clazz = exception.getClass();
     try {
       Constructor<? extends Throwable> ctor = clazz.getConstructor(String.class);
       Throwable t = ctor.newInstance(msg);
       return (T)(t.initCause(exception));
     } catch (Throwable e) {
-      LOG.warn("Unable to wrap exception of type " +
-          clazz + ": it has no (String) constructor", e);
-      return exception;
+      LOG.warn("Unable to wrap exception of type {}: it has no (String) "
+          + "constructor", clazz, e);
+      throw exception;
     }
   }
 

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

@@ -32,6 +32,7 @@ import java.net.SocketException;
 import java.net.SocketTimeoutException;
 import java.net.URI;
 import java.net.UnknownHostException;
+import java.nio.charset.CharacterCodingException;
 import java.util.Arrays;
 import java.util.Enumeration;
 import java.util.List;
@@ -40,6 +41,7 @@ import java.util.concurrent.TimeUnit;
 import org.apache.commons.lang.StringUtils;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.io.IOUtils;
+import org.apache.hadoop.security.KerberosAuthException;
 import org.apache.hadoop.security.NetUtilsTestResolver;
 import org.junit.Assume;
 import org.junit.Before;
@@ -262,6 +264,44 @@ public class TestNetUtils {
     assertInException(wrapped, "/EOFException");
   }
 
+  @Test
+  public void testWrapKerbAuthException() throws Throwable {
+    IOException e = new KerberosAuthException("socket timeout on connection");
+    IOException wrapped = verifyExceptionClass(e, KerberosAuthException.class);
+    assertInException(wrapped, "socket timeout on connection");
+    assertInException(wrapped, "localhost");
+    assertInException(wrapped, "DestHost:destPort ");
+    assertInException(wrapped, "LocalHost:localPort");
+    assertRemoteDetailsIncluded(wrapped);
+    assertInException(wrapped, "KerberosAuthException");
+  }
+
+  @Test
+  public void testWrapIOEWithNoStringConstructor() throws Throwable {
+    IOException e = new CharacterCodingException();
+    IOException wrapped = verifyExceptionClass(e, IOException.class);
+    assertInException(wrapped, "Failed on local exception");
+    assertNotInException(wrapped, NetUtils.HADOOP_WIKI);
+    assertInException(wrapped, "Host Details ");
+    assertRemoteDetailsIncluded(wrapped);
+  }
+
+  @Test
+  public void testWrapIOEWithPrivateStringConstructor() throws Throwable {
+    class TestIOException extends CharacterCodingException{
+      private  TestIOException(String cause){
+      }
+      TestIOException(){
+      }
+    }
+    IOException e = new TestIOException();
+    IOException wrapped = verifyExceptionClass(e, IOException.class);
+    assertInException(wrapped, "Failed on local exception");
+    assertNotInException(wrapped, NetUtils.HADOOP_WIKI);
+    assertInException(wrapped, "Host Details ");
+    assertRemoteDetailsIncluded(wrapped);
+  }
+
   @Test
   public void testWrapSocketException() throws Throwable {
     IOException wrapped = verifyExceptionClass(new SocketException("failed"),