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
@@ -731,83 +731,90 @@ public class NetUtils {
                                           final String localHost,
                                           final int localPort,
                                           final IOException exception) {
-    if (exception instanceof BindException) {
-      return wrapWithMessage(exception,
-          "Problem binding to ["
-              + localHost
-              + ":"
-              + localPort
-              + "] "
-              + exception
-              + ";"
-              + see("BindException"));
-    } else if (exception instanceof ConnectException) {
-      // Check if client was trying to connect to an unspecified IPv4 address
-      // (0.0.0.0) or IPv6 address(0:0:0:0:0:0:0:0 or ::)
-      if ((destHost != null && (destHost.equals("0.0.0.0") ||
-          destHost.equals("0:0:0:0:0:0:0:0") || destHost.equals("::")))
-          || destPort == 0) {
-        return wrapWithMessage(exception, "Your endpoint configuration" +
-            " is wrong;" + see("UnsetHostnameOrPort"));
-      } else {
-        // connection refused; include the host:port in the error
+    try {
+      if (exception instanceof BindException) {
         return wrapWithMessage(exception,
-            "Call From "
+            "Problem binding to ["
                 + localHost
-                + " to "
-                + destHost
                 + ":"
-                + destPort
-                + " failed on connection exception: "
+                + localPort
+                + "] "
                 + exception
                 + ";"
-                + see("ConnectionRefused"));
+                + see("BindException"));
+      } else if (exception instanceof ConnectException) {
+        // Check if client was trying to connect to an unspecified IPv4 address
+        // (0.0.0.0) or IPv6 address(0:0:0:0:0:0:0:0 or ::)
+        if ((destHost != null && (destHost.equals("0.0.0.0") ||
+            destHost.equals("0:0:0:0:0:0:0:0") || destHost.equals("::")))
+            || destPort == 0) {
+          return wrapWithMessage(exception, "Your endpoint configuration" +
+              " is wrong;" + see("UnsetHostnameOrPort"));
+        } else {
+          // connection refused; include the host:port in the error
+          return wrapWithMessage(exception,
+              "Call From "
+                  + localHost
+                  + " to "
+                  + destHost
+                  + ":"
+                  + destPort
+                  + " failed on connection exception: "
+                  + exception
+                  + ";"
+                  + see("ConnectionRefused"));
+        }
+      } else if (exception instanceof UnknownHostException) {
+        return wrapWithMessage(exception,
+            "Invalid host name: "
+                + getHostDetailsAsString(destHost, destPort, localHost)
+                + exception
+                + ";"
+                + see("UnknownHost"));
+      } else if (exception instanceof SocketTimeoutException) {
+        return wrapWithMessage(exception,
+            "Call From "
+                + localHost + " to " + destHost + ":" + destPort
+                + " failed on socket timeout exception: " + exception
+                + ";"
+                + see("SocketTimeout"));
+      } else if (exception instanceof NoRouteToHostException) {
+        return wrapWithMessage(exception,
+            "No Route to Host from  "
+                + localHost + " to " + destHost + ":" + destPort
+                + " failed on socket timeout exception: " + exception
+                + ";"
+                + see("NoRouteToHost"));
+      } else if (exception instanceof EOFException) {
+        return wrapWithMessage(exception,
+            "End of File Exception between "
+                + getHostDetailsAsString(destHost, destPort, localHost)
+                + ": " + 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 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 if (exception instanceof UnknownHostException) {
-      return wrapWithMessage(exception,
-          "Invalid host name: "
-              + getHostDetailsAsString(destHost, destPort, localHost)
-              + exception
-              + ";"
-              + see("UnknownHost"));
-    } else if (exception instanceof SocketTimeoutException) {
-      return wrapWithMessage(exception,
-          "Call From "
-              + localHost + " to " + destHost + ":" + destPort
-              + " failed on socket timeout exception: " + exception
-              + ";"
-              + see("SocketTimeout"));
-    } else if (exception instanceof NoRouteToHostException) {
-      return wrapWithMessage(exception,
-          "No Route to Host from  "
-              + localHost + " to " + destHost + ":" + destPort
-              + " failed on socket timeout exception: " + exception
-              + ";"
-              + see("NoRouteToHost"));
-    } else if (exception instanceof EOFException) {
-      return wrapWithMessage(exception,
-          "End of File Exception between "
-              + getHostDetailsAsString(destHost,  destPort, localHost)
-              + ": " + 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 {
+    } catch (IOException ex) {
       return (IOException) new IOException("Failed on local exception: "
-             + exception
-             + "; Host Details : "
-             + getHostDetailsAsString(destHost, destPort, localHost))
+          + 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"),