BeanPostProcessor for proxying TaskExecutor instances to allow delegation to an error handler when async execution throws errors.

Relates to INT-440

org.springframework.integration/src/main/java/org/springframework/integration/executor/ErrorHandlingExecutorBeanPostProcessor.java

@@ -0,0 +1,61 @@
+/*
+ * Copyright 2002-2008 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.integration.executor;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.springframework.aop.framework.ProxyFactory;
+import org.springframework.aop.support.DefaultPointcutAdvisor;
+import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.config.BeanPostProcessor;
+import org.springframework.core.task.TaskExecutor;
+import org.springframework.integration.util.ErrorHandler;
+
+/**
+ * 
+ * @author Jonas Partner
+ *
+ */
+public class ErrorHandlingExecutorBeanPostProcessor implements BeanPostProcessor {
+
+	private final RunnableProxyingMethodInterceptor runnableProxyingInterceptor;
+
+	private volatile List<String> beanNamesToExclude = new ArrayList<String>();
+
+	public ErrorHandlingExecutorBeanPostProcessor(ErrorHandler errorHandler) {
+		this.runnableProxyingInterceptor = new RunnableProxyingMethodInterceptor(errorHandler);
+	}
+
+	public void setTaskExecutorBeanNameExclusions(List<String> beanNamesToExclude) {
+		this.beanNamesToExclude = beanNamesToExclude;
+	}
+
+	public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
+		if (bean instanceof TaskExecutor && !beanNamesToExclude.contains(beanName)) {
+			ProxyFactory proxyFactory = new ProxyFactory(bean);
+			proxyFactory.addAdvisor(new DefaultPointcutAdvisor(this.runnableProxyingInterceptor));
+			return proxyFactory.getProxy();
+		}
+		return bean;
+	}
+
+	public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
+		return bean;
+	}
+
+}

org.springframework.integration/src/main/java/org/springframework/integration/executor/RunnableProxyingMethodInterceptor.java

@@ -0,0 +1,69 @@
+/*
+ * Copyright 2002-2008 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.integration.executor;
+
+import org.aopalliance.intercept.MethodInterceptor;
+import org.aopalliance.intercept.MethodInvocation;
+import org.springframework.aop.framework.ProxyFactory;
+import org.springframework.core.task.TaskExecutor;
+import org.springframework.integration.util.ErrorHandler;
+
+/**
+ * Used tby {@link ErrorHandlingExecutorBeanPostProcessor} to Proxy
+ * {@link TaskExecutor} instances. This allow the wrapping of {@link Runnable}
+ * instances in order to handle catch errors thrown and delegate handling to an
+ * instance of {@link ErrorHandler}
+ * @author Jonas Partner
+ * 
+ */
+public class RunnableProxyingMethodInterceptor implements MethodInterceptor {
+
+	private final ErrorHandler errorHandler;
+
+	public RunnableProxyingMethodInterceptor(ErrorHandler errorHandler) {
+		this.errorHandler = errorHandler;
+	}
+
+	public Object invoke(MethodInvocation invocation) throws Throwable {
+		Runnable runnable = (Runnable) invocation.getArguments()[0];
+		ProxyFactory factory = new ProxyFactory(runnable);
+		factory.addAdvice(new ErrorHandlingAdvice(errorHandler));
+		invocation.getArguments()[0] = factory.getProxy();
+		return invocation.proceed();
+	}
+
+	private static class ErrorHandlingAdvice implements MethodInterceptor {
+
+		private final ErrorHandler errorHandler;
+
+		public ErrorHandlingAdvice(ErrorHandler errorHandler) {
+			this.errorHandler = errorHandler;
+		}
+
+		public Object invoke(MethodInvocation invocation) throws Throwable {
+			try {
+				invocation.proceed();
+			}
+			catch (Throwable t) {
+				errorHandler.handle(t);
+			}
+			return null;
+		}
+
+	}
+
+}

org.springframework.integration/src/test/java/org/springframework/integration/executor/ErrorHandlingExecutorBeanPostProcessorTests-context.xml

@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://www.springframework.org/schema/beans
+			http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">
+
+
+
+	<bean id="proxiedTaskExecutor" class="org.springframework.core.task.SimpleAsyncTaskExecutor" />
+
+	<bean id="excludeFromProxyingTaskExecutor" class="org.springframework.core.task.SimpleAsyncTaskExecutor" />
+
+	<bean
+		class="org.springframework.integration.executor.ErrorHandlingExecutorBeanPostProcessor">
+		<constructor-arg ref="stubErrorHandler"/>
+		<property name="taskExecutorBeanNameExclusions">
+			<list>
+				<value>excludeFromProxyingTaskExecutor</value>
+			</list>
+		</property>
+	</bean>
+
+	<bean id="stubErrorHandler" class="org.springframework.integration.executor.StubErrorHandler"/>
+
+</beans>

org.springframework.integration/src/test/java/org/springframework/integration/executor/ErrorHandlingExecutorBeanPostProcessorTests.java

@@ -0,0 +1,76 @@
+/*
+ * Copyright 2002-2008 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.integration.executor;
+
+import static org.junit.Assert.*;
+
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.support.ClassPathXmlApplicationContext;
+import org.springframework.core.task.TaskExecutor;
+
+/**
+ * 
+ * @author Jonas Partner
+ *
+ */
+public class ErrorHandlingExecutorBeanPostProcessorTests {
+
+	StubErrorHandler errorHandler;
+	
+	ApplicationContext applicationContext;
+	
+	@Before
+	public void setUp(){
+		applicationContext = new ClassPathXmlApplicationContext(getClass().getSimpleName()+"-context.xml", getClass());
+		errorHandler = (StubErrorHandler)applicationContext.getBean("stubErrorHandler");
+	}
+	
+	@Test
+	public void testProxiedTaskExecutor() throws Exception{
+		TaskExecutor taskExecutor = (TaskExecutor)applicationContext.getBean("proxiedTaskExecutor");
+		ErrorThrowingRunnable runnable  = new ErrorThrowingRunnable();
+		taskExecutor.execute(runnable);
+		assertTrue("Runnable faield to run",runnable.latch.await(2, TimeUnit.SECONDS));
+		assertEquals("Incorrect count of exceptions", 1, errorHandler.throwables.size());
+	}
+	
+	@Test
+	public void testExcludedFromProxyingTaskExecutor() throws Exception{
+		TaskExecutor taskExecutor = (TaskExecutor)applicationContext.getBean("excludeFromProxyingTaskExecutor");
+		ErrorThrowingRunnable runnable  = new ErrorThrowingRunnable();
+		taskExecutor.execute(runnable);
+		runnable.latch.await(2, TimeUnit.SECONDS);
+		assertTrue("Runnable faield to run",runnable.latch.await(2, TimeUnit.SECONDS));
+		assertEquals("Incorrect count of exceptions", 0, errorHandler.throwables.size());
+	}
+	
+	private static class ErrorThrowingRunnable implements Runnable{
+
+		CountDownLatch latch = new CountDownLatch(1);
+		
+		public void run() {
+			latch.countDown();
+			throw new RuntimeException();
+			
+		}
+		
+	}
+}

org.springframework.integration/src/test/java/org/springframework/integration/executor/RunnableProxyingMethodInterceptorTests.java

@@ -0,0 +1,80 @@
+/*
+ * Copyright 2002-2008 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.integration.executor;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.springframework.aop.framework.ProxyFactory;
+import org.springframework.core.task.SimpleAsyncTaskExecutor;
+import org.springframework.core.task.TaskExecutor;
+import org.springframework.integration.util.ErrorHandler;
+
+/**
+ * 
+ * @author Jonas Partner
+ *
+ */
+public class RunnableProxyingMethodInterceptorTests {
+
+	TaskExecutor proxiedExecutor;
+
+	StubErrorHandler errorHandler;
+
+	@Before
+	public void setUp() {
+		errorHandler = new StubErrorHandler();
+		ProxyFactory factory = new ProxyFactory(new SimpleAsyncTaskExecutor());
+		factory.addAdvice(new RunnableProxyingMethodInterceptor(errorHandler));
+		proxiedExecutor = (TaskExecutor) factory.getProxy();
+	}
+
+	@Test
+	public void testRuntimeThrown() throws Exception {
+		TestRunnable runnable = new TestRunnable();
+
+		proxiedExecutor.execute(runnable);
+		assertTrue("Runnable did not run", runnable.countDown.await(2, TimeUnit.SECONDS));
+		assertEquals("Wrong count of exceptions in ErrorHandler", 1, errorHandler.throwables.size());
+	}
+
+	public static class StubErrorHandler implements ErrorHandler {
+
+		List<Throwable> throwables = new ArrayList<Throwable>();
+
+		public void handle(Throwable t) {
+			throwables.add(t);
+		}
+	}
+
+	public static class TestRunnable implements Runnable {
+		CountDownLatch countDown = new CountDownLatch(1);
+
+		public void run() {
+			countDown.countDown();
+			throw new RuntimeException();
+		}
+	}
+
+}

org.springframework.integration/src/test/java/org/springframework/integration/executor/StubErrorHandler.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2002-2008 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.integration.executor;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.springframework.integration.util.ErrorHandler;
+
+public class StubErrorHandler implements ErrorHandler {
+
+	List<Throwable> throwables = new ArrayList<Throwable>();
+	
+	public void handle(Throwable t) {
+		throwables.add(t);
+	}
+	
+
+}