Added the MessageBusAware interface, as well as the MessageBusAwareBeanPostProcessor for injecting the MessageBus in the implementing beans.

spring-integration-core/src/main/java/org/springframework/integration/bus/MessageBusAware.java

@@ -0,0 +1,28 @@
+/*
+ * 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.bus;
+
+/**
+ * Interface to be implemented by classes which need access to the {@link MessageBus}.
+ * @author Marius Bogoevici
+ *
+ */
+public interface MessageBusAware {
+
+	public void setMessageBus(MessageBus messageBus);
+	
+}

spring-integration-core/src/main/java/org/springframework/integration/bus/MessageBusAwareBeanPostProcessor.java

@@ -0,0 +1,51 @@
+/*
+ * 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.bus;
+
+import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.config.BeanPostProcessor;
+import org.springframework.util.Assert;
+
+/**
+ * A bean post processor which injects all {@link MessageBusAware} beans with a 
+ * reference to the {@link MessageBus}.
+ * 
+ * @author Marius Bogoevici
+ *
+ */
+public class MessageBusAwareBeanPostProcessor implements BeanPostProcessor {
+
+	private final MessageBus messageBus;
+	
+	public MessageBusAwareBeanPostProcessor(MessageBus messageBus) {
+		Assert.notNull(messageBus, "'messageBus' must not be null");
+		this.messageBus = messageBus;
+	}
+	
+	public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
+		if (bean instanceof MessageBusAware) {
+			((MessageBusAware) bean).setMessageBus(messageBus);
+		}
+		return bean;
+	}
+
+	public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
+		return bean;
+	}
+
+	
+}

spring-integration-core/src/test/java/org/springframework/integration/bus/MessageBusTests.java

@@ -25,10 +25,8 @@ import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
 
 import org.junit.Test;
-
 import org.springframework.beans.factory.BeanCreationException;
 import org.springframework.context.support.ClassPathXmlApplicationContext;
-import org.springframework.integration.ConfigurationException;
 import org.springframework.integration.channel.DispatcherPolicy;
 import org.springframework.integration.channel.MessageChannel;
 import org.springframework.integration.channel.QueueChannel;
@@ -219,17 +217,11 @@ public class MessageBusTests {
 		assertEquals(MessageDeliveryException.class, errorMessage.getPayload().getClass());
 	}
 
-	@Test
+	@Test(expected = BeanCreationException.class)
 	public void testMultipleMessageBusBeans() {
-		boolean exceptionThrown = false;
-		try {
-			new ClassPathXmlApplicationContext("multipleMessageBusBeans.xml", this.getClass());
-		}
-		catch (BeanCreationException e) {
-			exceptionThrown = true;
-			assertEquals(ConfigurationException.class, e.getCause().getClass());
-		}
-		assertTrue(exceptionThrown);
+		ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("multipleMessageBusBeans.xml", 
+				this.getClass());
+
 	}
 
 	@Test
@@ -259,6 +251,12 @@ public class MessageBusTests {
 		assertEquals("handler should have received error message", 0, latch.getCount());
 	}
 
+	@Test
+	public void testMessageBusAwareImpl() {
+		ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("messageBusTests.xml", this.getClass());
+		TestMessageBusAwareImpl messageBusAwareBean = (TestMessageBusAwareImpl) context.getBean("messageBusAwareBean");
+		assertTrue(messageBusAwareBean.getMessageBus() == context.getBean("bus"));
+	}
 
 	private static class FailingSource implements PollableSource<Object> {
 

spring-integration-core/src/test/java/org/springframework/integration/bus/messageBusTests.xml

@@ -21,5 +21,10 @@
 	</bean>
 
 	<bean id="handler" class="org.springframework.integration.handler.TestHandlers" factory-method="echoHandler"/>
-
+
+	<bean class="org.springframework.integration.bus.MessageBusAwareBeanPostProcessor">
+		<constructor-arg ref="bus"/>
+	</bean>
+	
+	<bean id= "messageBusAwareBean" class="org.springframework.integration.bus.TestMessageBusAwareImpl"/>
 </beans>