Factored out common source adapter behavior into AbstractSourceAdapter from PollingSourceAdapter and implemented ApplicationEventSourceAdapter.

spring-integration-core/src/main/java/org/springframework/integration/adapter/AbstractSourceAdapter.java

@@ -0,0 +1,65 @@
+/*
+ * Copyright 2002-2007 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.adapter;
+
+import org.springframework.integration.channel.MessageChannel;
+import org.springframework.integration.message.Message;
+import org.springframework.integration.message.MessageMapper;
+import org.springframework.integration.message.SimplePayloadMessageMapper;
+import org.springframework.util.Assert;
+
+/**
+ * A base class providing common behavior for source adapters.
+ * 
+ * @author Mark Fisher
+ */
+public class AbstractSourceAdapter<T> implements SourceAdapter {
+
+	private MessageChannel channel;
+
+	private MessageMapper<?,T> mapper = new SimplePayloadMessageMapper<T>();
+
+	private long sendTimeout = -1;
+
+
+	public void setChannel(MessageChannel channel) {
+		Assert.notNull(channel, "'channel' must not be null");
+		this.channel = channel;
+	}
+
+	public void setSendTimeout(long sendTimeout) {
+		this.sendTimeout = sendTimeout;
+	}
+
+	public void setMessageMapper(MessageMapper<?,T> mapper) {
+		Assert.notNull(mapper, "'mapper' must not be null");
+		this.mapper = mapper;
+	}
+
+	protected MessageMapper<?,T> getMessageMapper() {
+		return this.mapper;
+	}
+
+	protected boolean sendToChannel(T object) {
+		Message<?> message = this.mapper.toMessage(object);
+		if (this.sendTimeout < 0) {
+			return this.channel.send(message);
+		}
+		return this.channel.send(message, this.sendTimeout);
+	}
+
+}

spring-integration-core/src/main/java/org/springframework/integration/adapter/PollingSourceAdapter.java

@@ -22,9 +22,7 @@ import org.springframework.integration.MessageHandlingException;
 import org.springframework.integration.bus.ConsumerPolicy;
 import org.springframework.integration.bus.MessageDispatcher;
 import org.springframework.integration.channel.MessageChannel;
-import org.springframework.integration.message.Message;
 import org.springframework.integration.message.MessageMapper;
-import org.springframework.integration.message.SimplePayloadMessageMapper;
 import org.springframework.util.Assert;
 
 /**
@@ -34,49 +32,25 @@ import org.springframework.util.Assert;
  * 
  * @author Mark Fisher
  */
-public class PollingSourceAdapter<T> implements SourceAdapter, MessageDispatcher {
+public class PollingSourceAdapter<T> extends AbstractSourceAdapter<T> implements MessageDispatcher {
 
 	private static int DEFAULT_PERIOD = 1000;
 
 	private PollableSource<T> source;
 
-	private MessageChannel channel;
-
-	private MessageMapper<?,T> mapper = new SimplePayloadMessageMapper<T>();
-
 	private ConsumerPolicy policy = ConsumerPolicy.newPollingPolicy(DEFAULT_PERIOD);
 
-	private long sendTimeout = -1;
-
 
 	public PollingSourceAdapter(PollableSource<T> source) {
 		Assert.notNull(source, "'source' must not be null");
 		this.source = source;
 	}
 
-	public void setChannel(MessageChannel channel) {
-		Assert.notNull(channel, "'channel' must not be null");
-		this.channel = channel;
-	}
-
 	public void setPeriod(int period) {
 		Assert.isTrue(period > 0, "'period' must be a positive value");
 		this.policy.setPeriod(period);
 	}
 
-	public void setSendTimeout(long sendTimeout) {
-		this.sendTimeout = sendTimeout;
-	}
-
-	public void setMessageMapper(MessageMapper<?,T> mapper) {
-		Assert.notNull(mapper, "'mapper' must not be null");
-		this.mapper = mapper;
-	}
-
-	protected MessageMapper<?,T> getMessageMapper() {
-		return this.mapper;
-	}
-
 	public void setMaxMessagesPerTask(int maxMessagesPerTask) {
 		Assert.isTrue(maxMessagesPerTask > 0, "'maxMessagesPerTask' must be a positive value");
 		this.policy.setMaxMessagesPerTask(maxMessagesPerTask);
@@ -95,16 +69,8 @@ public class PollingSourceAdapter<T> implements SourceAdapter, MessageDispatcher
 				throw new MessageHandlingException("source returned too many results, the limit is " + limit);
 			}
 			for (T next : results) {
-				Message<?> message = this.mapper.toMessage(next);
-				if (this.sendTimeout < 0) {
-					if (this.channel.send(message)) {
-						messagesProcessed++;
-					}
-				}
-				else {
-					if (this.channel.send(message, this.sendTimeout)) {
-						messagesProcessed++;
-					}
+				if (this.sendToChannel(next)) {
+					messagesProcessed++;
 				}
 			}
 		}

spring-integration-core/src/main/java/org/springframework/integration/adapter/SourceAdapter.java

@@ -16,7 +16,6 @@
 
 package org.springframework.integration.adapter;
 
-import org.springframework.integration.bus.ConsumerPolicy;
 import org.springframework.integration.channel.MessageChannel;
 
 /**
@@ -28,6 +27,4 @@ public interface SourceAdapter {
 
 	void setChannel(MessageChannel channel);
 
-	ConsumerPolicy getConsumerPolicy();
-
 }

spring-integration-core/src/main/java/org/springframework/integration/adapter/event/ApplicationEventSourceAdapter.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright 2002-2007 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.adapter.event;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.springframework.context.ApplicationEvent;
+import org.springframework.context.ApplicationListener;
+import org.springframework.integration.adapter.AbstractSourceAdapter;
+import org.springframework.util.Assert;
+import org.springframework.util.CollectionUtils;
+
+/**
+ * A source adapter for passing Spring
+ * {@link ApplicationEvent ApplicationEvents} within messages.
+ * 
+ * @author Mark Fisher
+ */
+public class ApplicationEventSourceAdapter extends AbstractSourceAdapter<ApplicationEvent> implements
+		ApplicationListener {
+
+	private List<Class<? extends ApplicationEvent>> eventTypes = new ArrayList<Class<? extends ApplicationEvent>>();
+
+
+	/**
+	 * Set the list of event types (classes that extend ApplicationEvent) that
+	 * this adapter should send to the message channel. By default, all event
+	 * types will be sent.
+	 */
+	public void setEventTypes(List<Class<? extends ApplicationEvent>> eventTypes) {
+		Assert.notEmpty(eventTypes, "at least one event type is required");
+		this.eventTypes = eventTypes;
+	}
+
+	public void onApplicationEvent(ApplicationEvent event) {
+		if (CollectionUtils.isEmpty(this.eventTypes)) {
+			this.sendToChannel(event);
+			return;
+		}
+		for (Class<? extends ApplicationEvent> eventType : this.eventTypes) {
+			if (eventType.isAssignableFrom(event.getClass())) {
+				this.sendToChannel(event);
+				return;
+			}
+		}
+	}
+
+}

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

@@ -179,8 +179,9 @@ public class MessageBus implements ChannelRegistry, ApplicationContextAware, Lif
 	public void registerSourceAdapter(String name, SourceAdapter adapter) {
 		// TODO: use the name
 		if (adapter instanceof MessageDispatcher) {
-			ConsumerPolicy policy = adapter.getConsumerPolicy();
-			DispatcherTask dispatcherTask = new DispatcherTask((MessageDispatcher) adapter, policy);
+			MessageDispatcher dispatcher = (MessageDispatcher) adapter;
+			ConsumerPolicy policy = dispatcher.getConsumerPolicy();
+			DispatcherTask dispatcherTask = new DispatcherTask(dispatcher, policy);
 			this.addDispatcherTask(dispatcherTask);
 			if (logger.isInfoEnabled()) {
 				logger.info("registered source adapter '" + name + "'");

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

@@ -23,6 +23,8 @@ package org.springframework.integration.bus;
  */
 public interface MessageDispatcher {
 
+	ConsumerPolicy getConsumerPolicy();
+
 	int dispatch();
 
 }

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

@@ -38,6 +38,10 @@ public class UnicastMessageDispatcher extends AbstractMessageDispatcher {
 	}
 
 
+	public ConsumerPolicy getConsumerPolicy() {
+		return this.policy;
+	}
+
 	@Override
 	protected boolean dispatchMessage(Message<?> message) {
 		int attempts = 0;