Java API: ActionFuture#actionGet to automatically unwrap failures, closes #1292.

modules/elasticsearch/src/main/java/org/elasticsearch/action/ActionFuture.java

@@ -20,6 +20,7 @@
 package org.elasticsearch.action;
 
 import org.elasticsearch.ElasticSearchException;
+import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.unit.TimeValue;
 
 import java.util.concurrent.Future;
@@ -36,6 +37,10 @@ public interface ActionFuture<T> extends Future<T> {
      * Similar to {@link #get()}, just wrapping the {@link InterruptedException} with
      * {@link org.elasticsearch.ElasticSearchInterruptedException}, and throwing the actual
      * cause of the {@link java.util.concurrent.ExecutionException}.
+     *
+     * <p>Note, the actual cause is unwrapped to the actual failure (for example, unwrapped
+     * from {@link org.elasticsearch.transport.RemoteTransportException}. The root failure is
+     * still accessible using {@link #getRootFailure()}.
      */
     T actionGet() throws ElasticSearchException;
 
@@ -43,6 +48,10 @@ public interface ActionFuture<T> extends Future<T> {
      * Similar to {@link #get(long, java.util.concurrent.TimeUnit)}, just wrapping the {@link InterruptedException} with
      * {@link org.elasticsearch.ElasticSearchInterruptedException}, and throwing the actual
      * cause of the {@link java.util.concurrent.ExecutionException}.
+     *
+     * <p>Note, the actual cause is unwrapped to the actual failure (for example, unwrapped
+     * from {@link org.elasticsearch.transport.RemoteTransportException}. The root failure is
+     * still accessible using {@link #getRootFailure()}.
      */
     T actionGet(String timeout) throws ElasticSearchException;
 
@@ -51,6 +60,10 @@ public interface ActionFuture<T> extends Future<T> {
      * {@link org.elasticsearch.ElasticSearchInterruptedException}, and throwing the actual
      * cause of the {@link java.util.concurrent.ExecutionException}.
      *
+     * <p>Note, the actual cause is unwrapped to the actual failure (for example, unwrapped
+     * from {@link org.elasticsearch.transport.RemoteTransportException}. The root failure is
+     * still accessible using {@link #getRootFailure()}.
+     *
      * @param timeoutMillis Timeout in millis
      */
     T actionGet(long timeoutMillis) throws ElasticSearchException;
@@ -59,6 +72,10 @@ public interface ActionFuture<T> extends Future<T> {
      * Similar to {@link #get(long, java.util.concurrent.TimeUnit)}, just wrapping the {@link InterruptedException} with
      * {@link org.elasticsearch.ElasticSearchInterruptedException}, and throwing the actual
      * cause of the {@link java.util.concurrent.ExecutionException}.
+     *
+     * <p>Note, the actual cause is unwrapped to the actual failure (for example, unwrapped
+     * from {@link org.elasticsearch.transport.RemoteTransportException}. The root failure is
+     * still accessible using {@link #getRootFailure()}.
      */
     T actionGet(long timeout, TimeUnit unit) throws ElasticSearchException;
 
@@ -66,6 +83,15 @@ public interface ActionFuture<T> extends Future<T> {
      * Similar to {@link #get(long, java.util.concurrent.TimeUnit)}, just wrapping the {@link InterruptedException} with
      * {@link org.elasticsearch.ElasticSearchInterruptedException}, and throwing the actual
      * cause of the {@link java.util.concurrent.ExecutionException}.
+     *
+     * <p>Note, the actual cause is unwrapped to the actual failure (for example, unwrapped
+     * from {@link org.elasticsearch.transport.RemoteTransportException}. The root failure is
+     * still accessible using {@link #getRootFailure()}.
      */
     T actionGet(TimeValue timeout) throws ElasticSearchException;
+
+    /**
+     * The root (possibly) wrapped failure.
+     */
+    @Nullable Throwable getRootFailure();
 }

modules/elasticsearch/src/main/java/org/elasticsearch/action/support/AdapterActionFuture.java

@@ -37,17 +37,15 @@ import java.util.concurrent.TimeoutException;
  */
 public abstract class AdapterActionFuture<T, L> extends AbstractFuture<T> implements ActionFuture<T>, ActionListener<L> {
 
+    private Throwable rootFailure;
+
     @Override public T actionGet() throws ElasticSearchException {
         try {
             return get();
         } catch (InterruptedException e) {
             throw new ElasticSearchInterruptedException(e.getMessage());
         } catch (ExecutionException e) {
-            if (e.getCause() instanceof ElasticSearchException) {
-                throw (ElasticSearchException) e.getCause();
-            } else {
-                throw new UncategorizedExecutionException("Failed execution", e);
-            }
+            throw rethrowExecutionException(e);
         }
     }
 
@@ -71,11 +69,20 @@ public abstract class AdapterActionFuture<T, L> extends AbstractFuture<T> implem
         } catch (InterruptedException e) {
             throw new ElasticSearchInterruptedException(e.getMessage());
         } catch (ExecutionException e) {
-            if (e.getCause() instanceof ElasticSearchException) {
-                throw (ElasticSearchException) e.getCause();
-            } else {
-                throw new UncategorizedExecutionException("Failed execution", e);
+            throw rethrowExecutionException(e);
+        }
+    }
+
+    static ElasticSearchException rethrowExecutionException(ExecutionException e) {
+        if (e.getCause() instanceof ElasticSearchException) {
+            ElasticSearchException esEx = (ElasticSearchException) e.getCause();
+            Throwable root = esEx.unwrapCause();
+            if (root instanceof ElasticSearchException) {
+                return (ElasticSearchException) root;
             }
+            return new UncategorizedExecutionException("Failed execution", root);
+        } else {
+            return new UncategorizedExecutionException("Failed execution", e);
         }
     }
 
@@ -88,4 +95,8 @@ public abstract class AdapterActionFuture<T, L> extends AbstractFuture<T> implem
     }
 
     protected abstract T convert(L listenerResponse);
+
+    @Override public Throwable getRootFailure() {
+        return rootFailure;
+    }
 }

plugins/lang/groovy/src/main/groovy/org/elasticsearch/groovy/client/action/GActionFuture.java

@@ -160,4 +160,8 @@ public class GActionFuture<T> implements ListenableActionFuture<T>, ActionListen
     @Override public T get(long timeout, TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException {
         return future.get(timeout, unit);
     }
+
+    @Override public Throwable getRootFailure() {
+        return future.getRootFailure();
+    }
 }