Added MessageSource and MessageTarget interfaces (INT-13).

spring-eai-core/src/main/java/org/springframework/integration/MessageSource.java

@@ -0,0 +1,48 @@
+/*
+ * 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;
+
+import org.springframework.integration.message.Message;
+
+/**
+ * Base interface for any component that enables message reception.
+ * 
+ * @author Mark Fisher
+ */
+public interface MessageSource {
+
+	/**
+	 * Receive a message, blocking indefinitely if necessary.
+	 * 
+	 * @return the next available {@link Message} or
+	 * <code>null</code> if interrupted
+	 */
+	Message receive();
+
+	/**
+	 * Receive a message, blocking until either a message is
+	 * available or the specified timeout period elapses.
+	 * 
+	 * @param timeout the timeout in milliseconds
+	 * 
+	 * @return the next available {@link Message} or
+	 * <code>null</code> if the specified timeout period
+	 * elapses or the message reception is interrupted
+	 */
+	Message receive(long timeout);
+
+}

spring-eai-core/src/main/java/org/springframework/integration/MessageTarget.java

@@ -0,0 +1,51 @@
+/*
+ * 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;
+
+import org.springframework.integration.message.Message;
+
+/**
+ * Base interface for any component that enables message sending.
+ * 
+ * @author Mark Fisher
+ */
+public interface MessageTarget {
+
+	/**
+	 * Send a message, blocking indefinitely if necessary.
+	 * 
+	 * @param message the {@link Message} to send
+	 * 
+	 * @return <code>true</code> if the message is sent
+	 * successfully, <code>false</false> if interrupted
+	 */
+	boolean send(Message message);
+
+	/**
+	 * Send a message, blocking until either the message is
+	 * accepted or the specified timeout period elapses.
+	 * 
+	 * @param message the {@link Message} to send
+	 * @param timeout the timeout in milliseconds
+	 * 
+	 * @return <code>true</code> if the message is sent
+	 * successfully, <code>false</false> if the specified
+	 * timeout period elapses or the send is interrupted
+	 */
+	boolean send(Message message, long timeout);
+
+}

spring-eai-core/src/main/java/org/springframework/integration/channel/MessageChannel.java

@@ -16,22 +16,17 @@
 
 package org.springframework.integration.channel;
 
-import org.springframework.integration.message.Message;
+import org.springframework.integration.MessageSource;
+import org.springframework.integration.MessageTarget;
 
 /**
- * Base channel interface defining the common behavior
- * of sending and receiving messages.   
+ * Base channel interface to combine the definitions of {@link MessageSource}
+ * for message reception and and {@link MessageTarget} for message sending.
  * 
  * @author Mark Fisher
+ * @see MessageSource
+ * @see MessageTarget
  */
-public interface MessageChannel {
-
-	boolean send(Message message);
-
-	boolean send(Message message, long timeout);
-
-	Message receive();
-
-	Message receive(long timeout);
+public interface MessageChannel extends MessageSource, MessageTarget {
 
 }