Added ErrorHandler strategy for asynchronous tasks submitted to a scheduler. Replaced DelegatingExceptionProofRunnable with DelegatingErrorHandlingRunnable. Both ThreadPoolTaskScheduler and ConcurrentTaskScheduler now support the ErrorHandler strategy.

org.springframework.context/src/main/java/org/springframework/scheduling/concurrent/ConcurrentTaskScheduler.java

@@ -27,6 +27,8 @@ import java.util.concurrent.TimeUnit;
 import org.springframework.core.task.TaskRejectedException;
 import org.springframework.scheduling.TaskScheduler;
 import org.springframework.scheduling.Trigger;
+import org.springframework.scheduling.support.ErrorHandler;
+import org.springframework.util.Assert;
 
 /**
  * Adapter that takes a JDK 1.5 <code>java.util.concurrent.ScheduledExecutorService</code>
@@ -41,6 +43,7 @@ import org.springframework.scheduling.Trigger;
  * a separate definition of the present adapter class.
  *
  * @author Juergen Hoeller
+ * @author Mark Fisher
  * @since 3.0
  * @see java.util.concurrent.ScheduledExecutorService
  * @see java.util.concurrent.ScheduledThreadPoolExecutor
@@ -49,7 +52,9 @@ import org.springframework.scheduling.Trigger;
  */
 public class ConcurrentTaskScheduler extends ConcurrentTaskExecutor implements TaskScheduler {
 
-	private ScheduledExecutorService scheduledExecutor;
+	private volatile ScheduledExecutorService scheduledExecutor;
+
+	private volatile ErrorHandler errorHandler;
 
 
 	/**
@@ -101,10 +106,20 @@ public class ConcurrentTaskScheduler extends ConcurrentTaskExecutor implements T
 				(scheduledExecutor != null ? scheduledExecutor : Executors.newSingleThreadScheduledExecutor());
 	}
 
+	/**
+	 * Provide an {@link ErrorHandler} strategy.
+	 */
+	public void setErrorHandler(ErrorHandler errorHandler) {
+		Assert.notNull(errorHandler, "'errorHandler' must not be null");
+		this.errorHandler = errorHandler;
+	}
+
 
 	public ScheduledFuture schedule(Runnable task, Trigger trigger) {
 		try {
-			return new ReschedulingRunnable(task, trigger, this.scheduledExecutor).schedule();
+			ErrorHandler errorHandler = this.errorHandler != null ?
+					this.errorHandler : TaskUtils.getDefaultErrorHandler(true);
+			return new ReschedulingRunnable(task, trigger, this.scheduledExecutor, errorHandler).schedule();
 		}
 		catch (RejectedExecutionException ex) {
 			throw new TaskRejectedException("Executor [" + this.scheduledExecutor + "] did not accept task: " + task, ex);
@@ -114,7 +129,8 @@ public class ConcurrentTaskScheduler extends ConcurrentTaskExecutor implements T
 	public ScheduledFuture schedule(Runnable task, Date startTime) {
 		long initialDelay = startTime.getTime() - System.currentTimeMillis();
 		try {
-			return this.scheduledExecutor.schedule(task, initialDelay, TimeUnit.MILLISECONDS);
+			return this.scheduledExecutor.schedule(
+					errorHandlingTask(task, false), initialDelay, TimeUnit.MILLISECONDS);
 		}
 		catch (RejectedExecutionException ex) {
 			throw new TaskRejectedException("Executor [" + this.scheduledExecutor + "] did not accept task: " + task, ex);
@@ -124,7 +140,8 @@ public class ConcurrentTaskScheduler extends ConcurrentTaskExecutor implements T
 	public ScheduledFuture scheduleAtFixedRate(Runnable task, Date startTime, long period) {
 		long initialDelay = startTime.getTime() - System.currentTimeMillis();
 		try {
-			return this.scheduledExecutor.scheduleAtFixedRate(task, initialDelay, period, TimeUnit.MILLISECONDS);
+			return this.scheduledExecutor.scheduleAtFixedRate(
+					errorHandlingTask(task, true), initialDelay, period, TimeUnit.MILLISECONDS);
 		}
 		catch (RejectedExecutionException ex) {
 			throw new TaskRejectedException("Executor [" + this.scheduledExecutor + "] did not accept task: " + task, ex);
@@ -133,7 +150,8 @@ public class ConcurrentTaskScheduler extends ConcurrentTaskExecutor implements T
 
 	public ScheduledFuture scheduleAtFixedRate(Runnable task, long period) {
 		try {
-			return this.scheduledExecutor.scheduleAtFixedRate(task, 0, period, TimeUnit.MILLISECONDS);
+			return this.scheduledExecutor.scheduleAtFixedRate(
+					errorHandlingTask(task, true), 0, period, TimeUnit.MILLISECONDS);
 		}
 		catch (RejectedExecutionException ex) {
 			throw new TaskRejectedException("Executor [" + this.scheduledExecutor + "] did not accept task: " + task, ex);
@@ -143,7 +161,8 @@ public class ConcurrentTaskScheduler extends ConcurrentTaskExecutor implements T
 	public ScheduledFuture scheduleWithFixedDelay(Runnable task, Date startTime, long delay) {
 		long initialDelay = startTime.getTime() - System.currentTimeMillis();
 		try {
-			return this.scheduledExecutor.scheduleWithFixedDelay(task, initialDelay, delay, TimeUnit.MILLISECONDS);
+			return this.scheduledExecutor.scheduleWithFixedDelay(
+					errorHandlingTask(task, true), initialDelay, delay, TimeUnit.MILLISECONDS);
 		}
 		catch (RejectedExecutionException ex) {
 			throw new TaskRejectedException("Executor [" + this.scheduledExecutor + "] did not accept task: " + task, ex);
@@ -152,11 +171,16 @@ public class ConcurrentTaskScheduler extends ConcurrentTaskExecutor implements T
 
 	public ScheduledFuture scheduleWithFixedDelay(Runnable task, long delay) {
 		try {
-			return this.scheduledExecutor.scheduleWithFixedDelay(task, 0, delay, TimeUnit.MILLISECONDS);
+			return this.scheduledExecutor.scheduleWithFixedDelay(
+					errorHandlingTask(task, true), 0, delay, TimeUnit.MILLISECONDS);
 		}
 		catch (RejectedExecutionException ex) {
 			throw new TaskRejectedException("Executor [" + this.scheduledExecutor + "] did not accept task: " + task, ex);
 		}
 	}
 
+	private Runnable errorHandlingTask(Runnable task, boolean isRepeatingTask) {
+		return TaskUtils.errorHandlingTask(task, this.errorHandler, isRepeatingTask);
+	}
+
 }

org.springframework.context/src/main/java/org/springframework/scheduling/concurrent/ReschedulingRunnable.java

@@ -25,7 +25,8 @@ import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
 
 import org.springframework.scheduling.Trigger;
-import org.springframework.scheduling.support.DelegatingExceptionProofRunnable;
+import org.springframework.scheduling.support.DelegatingErrorHandlingRunnable;
+import org.springframework.scheduling.support.ErrorHandler;
 import org.springframework.scheduling.support.SimpleTriggerContext;
 
 /**
@@ -37,9 +38,10 @@ import org.springframework.scheduling.support.SimpleTriggerContext;
  * will be translated onto a delay for the next execution time (repeatedly).
  *
  * @author Juergen Hoeller
+ * @author Mark Fisher
  * @since 3.0
  */
-class ReschedulingRunnable extends DelegatingExceptionProofRunnable implements ScheduledFuture<Object> {
+class ReschedulingRunnable extends DelegatingErrorHandlingRunnable implements ScheduledFuture<Object> {
 
 	private final Trigger trigger;
 
@@ -51,29 +53,36 @@ class ReschedulingRunnable extends DelegatingExceptionProofRunnable implements S
 
 	private volatile Date scheduledExecutionTime;
 
+	private final Object triggerContextMonitor = new Object();
 
-	public ReschedulingRunnable(Runnable delegate, Trigger trigger, ScheduledExecutorService executor) {
-		super(delegate);
+
+	public ReschedulingRunnable(Runnable delegate, Trigger trigger, ScheduledExecutorService executor, ErrorHandler errorHandler) {
+		super(delegate, errorHandler);
 		this.trigger = trigger;
 		this.executor = executor;
 	}
 
 
 	public ScheduledFuture schedule() {
-		this.scheduledExecutionTime = this.trigger.nextExecutionTime(this.triggerContext);
-		if (this.scheduledExecutionTime == null) {
-			return null;
+		synchronized (this.triggerContextMonitor) {
+			this.scheduledExecutionTime = this.trigger.nextExecutionTime(this.triggerContext);
+			if (this.scheduledExecutionTime == null) {
+				return null;
+			}
+			long initialDelay = this.scheduledExecutionTime.getTime() - System.currentTimeMillis();
+			this.currentFuture = this.executor.schedule(this, initialDelay, TimeUnit.MILLISECONDS);
+			return this;
 		}
-		long initialDelay = this.scheduledExecutionTime.getTime() - System.currentTimeMillis();
-		this.currentFuture = this.executor.schedule(this, initialDelay, TimeUnit.MILLISECONDS);
-		return this;
 	}
 
+	@Override
 	public void run() {
 		Date actualExecutionTime = new Date();
-		getDelegate().run();
+		super.run();
 		Date completionTime = new Date();
-		this.triggerContext.update(this.scheduledExecutionTime, actualExecutionTime, completionTime);
+		synchronized (this.triggerContextMonitor) {
+			this.triggerContext.update(this.scheduledExecutionTime, actualExecutionTime, completionTime);
+		}
 		if (!this.currentFuture.isCancelled()) {
 			schedule();
 		}

org.springframework.context/src/main/java/org/springframework/scheduling/concurrent/ScheduledExecutorFactoryBean.java

@@ -24,7 +24,8 @@ import java.util.concurrent.ScheduledThreadPoolExecutor;
 import java.util.concurrent.ThreadFactory;
 
 import org.springframework.beans.factory.FactoryBean;
-import org.springframework.scheduling.support.DelegatingExceptionProofRunnable;
+import org.springframework.scheduling.support.DelegatingErrorHandlingRunnable;
+import org.springframework.scheduling.support.ErrorHandler;
 import org.springframework.util.Assert;
 import org.springframework.util.ObjectUtils;
 
@@ -185,16 +186,18 @@ public class ScheduledExecutorFactoryBean extends ExecutorConfigurationSupport
 	/**
 	 * Determine the actual Runnable to schedule for the given task.
 	 * <p>Wraps the task's Runnable in a
-	 * {@link org.springframework.scheduling.support.DelegatingExceptionProofRunnable}
-	 * if necessary, according to the
+	 * {@link org.springframework.scheduling.support.DelegatingErrorHandlingRunnable}
+	 * that will catch and log the Exception. If necessary, it will suppress the
+	 * Exception according to the
 	 * {@link #setContinueScheduledExecutionAfterException "continueScheduledExecutionAfterException"}
 	 * flag.
 	 * @param task the ScheduledExecutorTask to schedule
 	 * @return the actual Runnable to schedule (may be a decorator)
 	 */
 	protected Runnable getRunnableToSchedule(ScheduledExecutorTask task) {
-		boolean propagateException = !this.continueScheduledExecutionAfterException;
-		return new DelegatingExceptionProofRunnable(task.getRunnable(), propagateException);
+		return this.continueScheduledExecutionAfterException
+				? new DelegatingErrorHandlingRunnable(task.getRunnable(), ErrorHandler.LOG_AND_SUPPRESS)
+				: new DelegatingErrorHandlingRunnable(task.getRunnable(), ErrorHandler.LOG_AND_PROPAGATE);
 	}
 
 

org.springframework.context/src/main/java/org/springframework/scheduling/concurrent/TaskUtils.java

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2002-2009 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.scheduling.concurrent;
+
+import java.util.concurrent.Future;
+
+import org.springframework.scheduling.support.DelegatingErrorHandlingRunnable;
+import org.springframework.scheduling.support.ErrorHandler;
+
+/**
+ * @author Mark Fisher
+ * @since 3.0
+ */
+abstract class TaskUtils {
+
+	/**
+	 * Decorates the task for error handling. If the provided
+	 * {@link ErrorHandler} is not null, it will be used. Otherwise,
+	 * repeating tasks will have errors suppressed by default whereas
+	 * one-shot tasks will have errors propagated by default since those
+	 * errors may be expected through the returned {@link Future}. In both
+	 * cases, the errors will be logged.
+	 */
+	static DelegatingErrorHandlingRunnable errorHandlingTask(
+			Runnable task, ErrorHandler errorHandler, boolean isRepeatingTask) {
+
+		if (task instanceof DelegatingErrorHandlingRunnable) {
+			return (DelegatingErrorHandlingRunnable) task;
+		}
+		ErrorHandler eh = errorHandler != null ? errorHandler : getDefaultErrorHandler(isRepeatingTask);
+		return new DelegatingErrorHandlingRunnable(task, eh);
+	}
+
+	static ErrorHandler getDefaultErrorHandler(boolean isRepeatingTask) {
+		return (isRepeatingTask ? ErrorHandler.LOG_AND_SUPPRESS : ErrorHandler.LOG_AND_PROPAGATE);
+	}
+
+}

org.springframework.context/src/main/java/org/springframework/scheduling/concurrent/ThreadPoolTaskScheduler.java

@@ -33,6 +33,7 @@ import org.springframework.core.task.TaskRejectedException;
 import org.springframework.scheduling.SchedulingTaskExecutor;
 import org.springframework.scheduling.TaskScheduler;
 import org.springframework.scheduling.Trigger;
+import org.springframework.scheduling.support.ErrorHandler;
 import org.springframework.util.Assert;
 
 /**
@@ -40,16 +41,20 @@ import org.springframework.util.Assert;
  * a native {@link java.util.concurrent.ScheduledThreadPoolExecutor}.
  *
  * @author Juergen Hoeller
+ * @author Mark Fisher
  * @since 3.0
  * @see #setPoolSize
  * @see #setThreadFactory
+ * @see #setErrorHandler
  */
 public class ThreadPoolTaskScheduler extends ExecutorConfigurationSupport
 		implements TaskScheduler, SchedulingTaskExecutor {
 
-	private int poolSize = 1;
+	private volatile int poolSize = 1;
 
-	private ScheduledExecutorService scheduledExecutor;
+	private volatile ScheduledExecutorService scheduledExecutor;
+
+	private volatile ErrorHandler errorHandler;
 
 
 	/**
@@ -61,6 +66,13 @@ public class ThreadPoolTaskScheduler extends ExecutorConfigurationSupport
 		this.poolSize = poolSize;
 	}
 
+	/**
+	 * Provide an {@link ErrorHandler} strategy.
+	 */
+	public void setErrorHandler(ErrorHandler errorHandler) {
+		Assert.notNull(errorHandler, "'errorHandler' must not be null");
+		this.errorHandler = errorHandler;
+	}
 
 	protected ExecutorService initializeExecutor(
 			ThreadFactory threadFactory, RejectedExecutionHandler rejectedExecutionHandler) {
@@ -102,7 +114,7 @@ public class ThreadPoolTaskScheduler extends ExecutorConfigurationSupport
 	public void execute(Runnable task) {
 		Executor executor = getScheduledExecutor();
 		try {
-			executor.execute(task);
+			executor.execute(errorHandlingTask(task, false));
 		}
 		catch (RejectedExecutionException ex) {
 			throw new TaskRejectedException("Executor [" + executor + "] did not accept task: " + task, ex);
@@ -116,7 +128,7 @@ public class ThreadPoolTaskScheduler extends ExecutorConfigurationSupport
 	public Future<?> submit(Runnable task) {
 		ExecutorService executor = getScheduledExecutor();
 		try {
-			return executor.submit(task);
+			return executor.submit(errorHandlingTask(task, false));
 		}
 		catch (RejectedExecutionException ex) {
 			throw new TaskRejectedException("Executor [" + executor + "] did not accept task: " + task, ex);
@@ -126,6 +138,9 @@ public class ThreadPoolTaskScheduler extends ExecutorConfigurationSupport
 	public <T> Future<T> submit(Callable<T> task) {
 		ExecutorService executor = getScheduledExecutor();
 		try {
+			if (this.errorHandler != null) {
+				task = new DelegatingErrorHandlingCallable<T>(task, this.errorHandler);
+			}
 			return executor.submit(task);
 		}
 		catch (RejectedExecutionException ex) {
@@ -143,7 +158,9 @@ public class ThreadPoolTaskScheduler extends ExecutorConfigurationSupport
 	public ScheduledFuture schedule(Runnable task, Trigger trigger) {
 		ScheduledExecutorService executor = getScheduledExecutor();
 		try {
-			return new ReschedulingRunnable(task, trigger, executor).schedule();
+			ErrorHandler errorHandler = this.errorHandler != null ?
+					this.errorHandler : TaskUtils.getDefaultErrorHandler(true); 
+			return new ReschedulingRunnable(task, trigger, executor, errorHandler).schedule();
 		}
 		catch (RejectedExecutionException ex) {
 			throw new TaskRejectedException("Executor [" + executor + "] did not accept task: " + task, ex);
@@ -154,7 +171,7 @@ public class ThreadPoolTaskScheduler extends ExecutorConfigurationSupport
 		ScheduledExecutorService executor = getScheduledExecutor();
 		long initialDelay = startTime.getTime() - System.currentTimeMillis();
 		try {
-			return executor.schedule(task, initialDelay, TimeUnit.MILLISECONDS);
+			return executor.schedule(errorHandlingTask(task, false), initialDelay, TimeUnit.MILLISECONDS);
 		}
 		catch (RejectedExecutionException ex) {
 			throw new TaskRejectedException("Executor [" + executor + "] did not accept task: " + task, ex);
@@ -165,7 +182,7 @@ public class ThreadPoolTaskScheduler extends ExecutorConfigurationSupport
 		ScheduledExecutorService executor = getScheduledExecutor();
 		long initialDelay = startTime.getTime() - System.currentTimeMillis();
 		try {
-			return executor.scheduleAtFixedRate(task, initialDelay, period, TimeUnit.MILLISECONDS);
+			return executor.scheduleAtFixedRate(errorHandlingTask(task, true), initialDelay, period, TimeUnit.MILLISECONDS);
 		}
 		catch (RejectedExecutionException ex) {
 			throw new TaskRejectedException("Executor [" + executor + "] did not accept task: " + task, ex);
@@ -175,7 +192,7 @@ public class ThreadPoolTaskScheduler extends ExecutorConfigurationSupport
 	public ScheduledFuture scheduleAtFixedRate(Runnable task, long period) {
 		ScheduledExecutorService executor = getScheduledExecutor();
 		try {
-			return executor.scheduleAtFixedRate(task, 0, period, TimeUnit.MILLISECONDS);
+			return executor.scheduleAtFixedRate(errorHandlingTask(task, true), 0, period, TimeUnit.MILLISECONDS);
 		}
 		catch (RejectedExecutionException ex) {
 			throw new TaskRejectedException("Executor [" + executor + "] did not accept task: " + task, ex);
@@ -186,7 +203,7 @@ public class ThreadPoolTaskScheduler extends ExecutorConfigurationSupport
 		ScheduledExecutorService executor = getScheduledExecutor();
 		long initialDelay = startTime.getTime() - System.currentTimeMillis();
 		try {
-			return executor.scheduleWithFixedDelay(task, initialDelay, delay, TimeUnit.MILLISECONDS);
+			return executor.scheduleWithFixedDelay(errorHandlingTask(task, true), initialDelay, delay, TimeUnit.MILLISECONDS);
 		}
 		catch (RejectedExecutionException ex) {
 			throw new TaskRejectedException("Executor [" + executor + "] did not accept task: " + task, ex);
@@ -196,11 +213,38 @@ public class ThreadPoolTaskScheduler extends ExecutorConfigurationSupport
 	public ScheduledFuture scheduleWithFixedDelay(Runnable task, long delay) {
 		ScheduledExecutorService executor = getScheduledExecutor();
 		try {
-			return executor.scheduleWithFixedDelay(task, 0, delay, TimeUnit.MILLISECONDS);
+			return executor.scheduleWithFixedDelay(errorHandlingTask(task, true), 0, delay, TimeUnit.MILLISECONDS);
 		}
 		catch (RejectedExecutionException ex) {
 			throw new TaskRejectedException("Executor [" + executor + "] did not accept task: " + task, ex);
 		}
 	}
 
+	private Runnable errorHandlingTask(Runnable task, boolean isRepeatingTask) {
+		return TaskUtils.errorHandlingTask(task, this.errorHandler, isRepeatingTask);
+	}
+
+
+	private static class DelegatingErrorHandlingCallable<V> implements Callable<V> {
+
+		private final Callable<V> delegate;
+
+		private final ErrorHandler errorHandler;
+
+		DelegatingErrorHandlingCallable(Callable<V> delegate, ErrorHandler errorHandler) {
+			this.delegate = delegate;
+			this.errorHandler = errorHandler;
+		}
+
+		public V call() throws Exception {
+			try {
+				return delegate.call();
+			}
+			catch (Throwable t) {
+				this.errorHandler.handleError(t);
+				return null;
+			}
+		}
+	}
+
 }

org.springframework.context/src/main/java/org/springframework/scheduling/support/DelegatingErrorHandlingRunnable.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright 2002-2009 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.scheduling.support;
+
+import org.springframework.util.Assert;
+
+/**
+ * Runnable wrapper that catches any exception or error thrown from its
+ * delegate Runnable and allows an {@link ErrorHandler} to handle it.
+ *
+ * @author Juergen Hoeller
+ * @author Mark Fisher
+ * @since 3.0
+ */
+public class DelegatingErrorHandlingRunnable implements Runnable {
+
+	private final Runnable delegate;
+
+	private final ErrorHandler errorHandler;
+
+
+	/**
+	 * Create a new DelegatingErrorHandlingRunnable.
+	 * @param delegate the Runnable implementation to delegate to
+	 * @param errorHandler the ErrorHandler for handling any exceptions
+	 */
+	public DelegatingErrorHandlingRunnable(Runnable delegate, ErrorHandler errorHandler) {
+		Assert.notNull(delegate, "Delegate must not be null");
+		Assert.notNull(errorHandler, "ErrorHandler must not be null");
+		this.delegate = delegate;
+		this.errorHandler = errorHandler;
+	}
+
+	public void run() {
+		try {
+			this.delegate.run();
+		}
+		catch (Throwable ex) {
+			this.errorHandler.handleError(ex);
+		}
+	}
+
+	@Override
+	public String toString() {
+		return "DelegatingErrorHandlingRunnable for " + this.delegate;
+	}
+
+}

org.springframework.context/src/main/java/org/springframework/scheduling/support/DelegatingExceptionProofRunnable.java

@@ -1,91 +0,0 @@
-/*
- * Copyright 2002-2009 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.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.springframework.scheduling.support;
-
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
-
-import org.springframework.util.Assert;
-import org.springframework.util.ReflectionUtils;
-
-/**
- * Runnable wrapper that catches any exception or error thrown
- * from its delegate Runnable. Used for continuing scheduled
- * execution even after an exception thrown from a task's Runnable.
- *
- * @author Juergen Hoeller
- * @since 2.0.5
- */
-public class DelegatingExceptionProofRunnable implements Runnable {
-
-	private static final Log logger = LogFactory.getLog(DelegatingExceptionProofRunnable.class);
-
-	private final Runnable delegate;
-
-	private final boolean propagateException;
-
-
-	/**
-	 * Create a new DelegatingExceptionProofRunnable that logs the exception
-	 * but isn't propagating it (in order to continue scheduled execution).
-	 * @param delegate the Runnable implementation to delegate to
-	 */
-	public DelegatingExceptionProofRunnable(Runnable delegate) {
-		Assert.notNull(delegate, "Delegate must not be null");
-		this.delegate = delegate;
-		this.propagateException = false;
-	}
-
-	/**
-	 * Create a new DelegatingExceptionProofRunnable.
-	 * @param delegate the Runnable implementation to delegate to
-	 * @param propagateException whether to propagate the exception after logging
-	 * (note: this will typically cancel scheduled execution of the runnable)
-	 */
-	public DelegatingExceptionProofRunnable(Runnable delegate, boolean propagateException) {
-		Assert.notNull(delegate, "Delegate must not be null");
-		this.delegate = delegate;
-		this.propagateException = propagateException;
-	}
-
-	/**
-	 * Return the wrapped Runnable implementation.
-	 */
-	public final Runnable getDelegate() {
-		return this.delegate;
-	}
-
-
-	public void run() {
-		try {
-			this.delegate.run();
-		}
-		catch (Throwable ex) {
-			logger.error("Unexpected exception thrown from Runnable: " + this.delegate, ex);
-			if (this.propagateException) {
-				ReflectionUtils.rethrowRuntimeException(ex);
-			}
-		}
-	}
-
-
-	@Override
-	public String toString() {
-		return "DelegatingExceptionProofRunnable for " + this.delegate;
-	}
-
-}

org.springframework.context/src/main/java/org/springframework/scheduling/support/ErrorHandler.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright 2002-2009 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.scheduling.support;
+
+/**
+ * A strategy for handling errors that occur during asynchronous
+ * execution of tasks that have been submitted to a TaskScheduler.
+ * 
+ * @author Mark Fisher
+ * @since 3.0.
+ */
+public interface ErrorHandler {
+
+	/**
+	 * An ErrorHandler strategy that will log the Exception but perform
+	 * no further handling. This will suppress the error so that
+	 * subsequent executions of the task will not be prevented.
+	 */
+	static final ErrorHandler LOG_AND_SUPPRESS = new LoggingErrorHandler();
+
+	/**
+	 * An ErrorHandler strategy that will log at error level and then
+	 * re-throw the Exception. Note: this will typically prevent subsequent
+	 * execution of a scheduled task.
+	 */
+	static final ErrorHandler LOG_AND_PROPAGATE = new PropagatingErrorHandler();
+
+
+	void handleError(Throwable t);
+
+}

org.springframework.context/src/main/java/org/springframework/scheduling/support/LoggingErrorHandler.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2002-2009 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.scheduling.support;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+/**
+ * An {@link ErrorHandler} implementation that logs the Throwable at error
+ * level. It does not perform any additional error handling. This can be
+ * useful when suppression of errors is the intended behavior.
+ * 
+ * @author Mark Fisher
+ * @since 3.0
+ */
+class LoggingErrorHandler implements ErrorHandler {
+
+	private final Log logger = LogFactory.getLog(LoggingErrorHandler.class);
+
+	public void handleError(Throwable t) {
+		if (logger.isErrorEnabled()) {
+			logger.error("Unexpected error occurred in scheduled task.", t);
+		}
+	}
+
+}

org.springframework.context/src/main/java/org/springframework/scheduling/support/PropagatingErrorHandler.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2002-2009 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.scheduling.support;
+
+import org.springframework.util.ReflectionUtils;
+
+/**
+ * An {@link ErrorHandler} implementation that logs the Throwable at error
+ * level and then propagates it.
+ * 
+ * @author Mark Fisher
+ * @since 3.0
+ */
+class PropagatingErrorHandler extends LoggingErrorHandler {
+
+	public void handleError(Throwable t) {
+		super.handleError(t);
+		ReflectionUtils.rethrowRuntimeException(t);
+	}
+
+}