SettableListenableFuture properly rethrows Error

Issue: SPR-14298
(cherry picked from commit a979885)

Author: jhoeller

spring-core/src/main/java/org/springframework/util/concurrent/SettableListenableFuture.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,6 +23,7 @@
 import java.util.concurrent.atomic.AtomicReference;
 
 import org.springframework.util.Assert;
+import org.springframework.util.ReflectionUtils;
 
 /**
  * A {@link org.springframework.util.concurrent.ListenableFuture ListenableFuture}
@@ -49,11 +50,11 @@ public SettableListenableFuture() {
 
 
 	/**
-	 * Set the value of this future. This method will return {@code true} if
-	 * the value was set successfully, or {@code false} if the future has already
-	 * been set or cancelled.
-	 * @param value the value that will be set.
-	 * @return {@code true} if the value was successfully set, else {@code false}.
+	 * Set the value of this future. This method will return {@code true} if the
+	 * value was set successfully, or {@code false} if the future has already been
+	 * set or cancelled.
+	 * @param value the value that will be set
+	 * @return {@code true} if the value was successfully set, else {@code false}
 	 */
 	public boolean set(T value) {
 		boolean success = this.settableTask.setValue(value);
@@ -64,14 +65,14 @@ public boolean set(T value) {
 	}
 
 	/**
-	 * Set the exception of this future. This method will return {@code true} if
-	 * the exception was set successfully, or {@code false} if the future has already
-	 * been set or cancelled.
-	 * @param exception the value that will be set.
-	 * @return {@code true} if the exception was successfully set, else {@code false}.
+	 * Set the exception of this future. This method will return {@code true} if the
+	 * exception was set successfully, or {@code false} if the future has already been
+	 * set or cancelled.
+	 * @param exception the value that will be set
+	 * @return {@code true} if the exception was successfully set, else {@code false}
 	 */
 	public boolean setException(Throwable exception) {
-		Assert.notNull(exception, "'exception' must not be null");
+		Assert.notNull(exception, "Exception must not be null");
 		boolean success = this.settableTask.setException(exception);
 		if (success) {
 			this.listenableFuture.run();
@@ -149,7 +150,7 @@ protected void interruptTask() {
 
 	private static class SettableTask<T> implements Callable<T> {
 
-		private static final String NO_VALUE = SettableListenableFuture.class.getName() + ".NO_VALUE";
+		private static final Object NO_VALUE = new Object();
 
 		private final AtomicReference<Object> value = new AtomicReference<Object>(NO_VALUE);
 
@@ -176,10 +177,11 @@ public void setCancelled() {
 		@SuppressWarnings("unchecked")
 		@Override
 		public T call() throws Exception {
-			if (value.get() instanceof Exception) {
-				throw (Exception) value.get();
+			Object val = this.value.get();
+			if (val instanceof Throwable) {
+				ReflectionUtils.rethrowException((Throwable) val);
 			}
-			return (T) value.get();
+			return (T) val;
 		}
 	}
 

spring-core/src/test/java/org/springframework/util/concurrent/SettableListenableFutureTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,7 +21,6 @@
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
 
-import org.junit.Before;
 import org.junit.Test;
 
 import static org.hamcrest.Matchers.*;
@@ -35,12 +34,8 @@
 @SuppressWarnings({ "rawtypes", "unchecked" })
 public class SettableListenableFutureTests {
 
-	private SettableListenableFuture<String> settableListenableFuture;
+	private final SettableListenableFuture<String> settableListenableFuture = new SettableListenableFuture<String>();
 
-	@Before
-	public void setUp() {
-		settableListenableFuture = new SettableListenableFuture<String>();
-	}
 
 	@Test
 	public void validateInitialValues() {
@@ -76,6 +71,20 @@ public void throwsSetExceptionWrappedInExecutionException() throws ExecutionExce
 		}
 	}
 
+	@Test
+	public void throwsSetErrorWrappedInExecutionException() throws ExecutionException, InterruptedException {
+		Throwable exception = new OutOfMemoryError();
+		boolean wasSet = settableListenableFuture.setException(exception);
+		assertTrue(wasSet);
+		try {
+			settableListenableFuture.get();
+			fail("Expected ExecutionException");
+		}
+		catch (ExecutionException ex) {
+			assertThat(ex.getCause(), equalTo(exception));
+		}
+	}
+
 	@Test
 	public void setValueTriggersCallback() {
 		String string = "hello";
@@ -85,7 +94,6 @@ public void setValueTriggersCallback() {
 			public void onSuccess(String result) {
 				callbackHolder[0] = result;
 			}
-
 			@Override
 			public void onFailure(Throwable ex) {
 				fail("Expected onSuccess() to be called");
@@ -104,7 +112,6 @@ public void setValueTriggersCallbackOnlyOnce() {
 			public void onSuccess(String result) {
 				callbackHolder[0] = result;
 			}
-
 			@Override
 			public void onFailure(Throwable ex) {
 				fail("Expected onSuccess() to be called");
@@ -124,7 +131,6 @@ public void setExceptionTriggersCallback() {
 			public void onSuccess(String result) {
 				fail("Expected onFailure() to be called");
 			}
-
 			@Override
 			public void onFailure(Throwable ex) {
 				callbackHolder[0] = ex;
@@ -143,7 +149,6 @@ public void setExceptionTriggersCallbackOnlyOnce() {
 			public void onSuccess(String result) {
 				fail("Expected onFailure() to be called");
 			}
-
 			@Override
 			public void onFailure(Throwable ex) {
 				callbackHolder[0] = ex;
@@ -169,7 +174,8 @@ public void run() {
 				try {
 					Thread.sleep(20L);
 					settableListenableFuture.set(string);
-				} catch (InterruptedException ex) {
+				}
+				catch (InterruptedException ex) {
 					throw new RuntimeException(ex);
 				}
 			}
@@ -183,7 +189,8 @@ public void getWithTimeoutThrowsTimeoutException() throws ExecutionException, In
 		try {
 			settableListenableFuture.get(1L, TimeUnit.MILLISECONDS);
 			fail("Expected TimeoutException");
-		} catch (TimeoutException ex) {
+		}
+		catch (TimeoutException ex) {
 			// expected
 		}
 	}
@@ -197,7 +204,8 @@ public void run() {
 				try {
 					Thread.sleep(20L);
 					settableListenableFuture.set(string);
-				} catch (InterruptedException ex) {
+				}
+				catch (InterruptedException ex) {
 					throw new RuntimeException(ex);
 				}
 			}
@@ -278,15 +286,17 @@ public void run() {
 				try {
 					Thread.sleep(20L);
 					settableListenableFuture.cancel(true);
-				} catch (InterruptedException ex) {
+				}
+				catch (InterruptedException ex) {
 					throw new RuntimeException(ex);
 				}
 			}
 		}).start();
 		try {
 			settableListenableFuture.get(100L, TimeUnit.MILLISECONDS);
 			fail("Expected CancellationException");
-		} catch (CancellationException ex) {
+		}
+		catch (CancellationException ex) {
 			// expected
 		}
 	}
@@ -317,6 +327,7 @@ public void cancelDoesNotNotifyCallbacksOnSetException() {
 		verifyNoMoreInteractions(callback);
 	}
 
+
 	private static class InterruptableSettableListenableFuture extends SettableListenableFuture<String> {
 
 		private boolean interrupted = false;
@@ -330,4 +341,5 @@ boolean calledInterruptTask() {
 			return interrupted;
 		}
 	}
+
 }