Initial commit of MessageHandlerChain (INT-391).

org.springframework.integration/src/test/java/org/springframework/integration/handler/MessageHandlerChainTests.java

@@ -0,0 +1,122 @@
+/*
+ * 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.handler;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.Test;
+
+import org.springframework.beans.factory.support.DefaultListableBeanFactory;
+import org.springframework.integration.channel.QueueChannel;
+import org.springframework.integration.core.Message;
+import org.springframework.integration.message.MessageBuilder;
+import org.springframework.integration.message.MessageHandler;
+import org.springframework.integration.message.StringMessage;
+
+/**
+ * @author Mark Fisher
+ */
+public class MessageHandlerChainTests {
+
+	@Test
+	public void chainWithOutputChannel() {
+		QueueChannel outputChannel = new QueueChannel();
+		List<MessageHandler> handlers = new ArrayList<MessageHandler>();
+		handlers.add(createHandler(1));
+		handlers.add(createHandler(2));
+		handlers.add(createHandler(3));
+		MessageHandlerChain chain = new MessageHandlerChain();
+		chain.setBeanName("testChain");
+		chain.setHandlers(handlers);
+		chain.setOutputChannel(outputChannel);
+		chain.handleMessage(new StringMessage("test"));
+		Message<?> reply = outputChannel.receive(0);
+		assertNotNull(reply);
+		assertEquals("test123", reply.getPayload());
+	}
+
+	@Test(expected = IllegalArgumentException.class)
+	public void chainWithOutputChannelButLastHandlerDoesNotProduceReplies() {
+		QueueChannel outputChannel = new QueueChannel();
+		List<MessageHandler> handlers = new ArrayList<MessageHandler>();
+		handlers.add(createHandler(1));
+		handlers.add(createHandler(2));
+		handlers.add(new MessageHandler() {
+			public void handleMessage(Message<?> message) {
+			}
+		});
+		MessageHandlerChain chain = new MessageHandlerChain();
+		chain.setBeanName("testChain");
+		chain.setHandlers(handlers);
+		chain.setOutputChannel(outputChannel);
+		chain.handleMessage(new StringMessage("test"));
+	}
+
+	@Test
+	public void chainForwardsToReplyChannel() {
+		QueueChannel replyChannel = new QueueChannel();
+		List<MessageHandler> handlers = new ArrayList<MessageHandler>();
+		handlers.add(createHandler(1));
+		handlers.add(createHandler(2));
+		handlers.add(createHandler(3));
+		MessageHandlerChain chain = new MessageHandlerChain();
+		chain.setBeanName("testChain");
+		chain.setHandlers(handlers);
+		Message<String> message = MessageBuilder.withPayload("test")
+				.setReplyChannel(replyChannel).build();
+		chain.handleMessage(message);
+		Message<?> reply = replyChannel.receive(0);
+		assertNotNull(reply);
+		assertEquals("test123", reply.getPayload());
+	}
+
+	@Test
+	public void chainResolvesReplyChannelName() {
+		QueueChannel replyChannel = new QueueChannel();
+		DefaultListableBeanFactory beanFactory = new DefaultListableBeanFactory();
+		beanFactory.registerSingleton("testChannel", replyChannel);
+		List<MessageHandler> handlers = new ArrayList<MessageHandler>();
+		handlers.add(createHandler(1));
+		handlers.add(createHandler(2));
+		handlers.add(createHandler(3));
+		MessageHandlerChain chain = new MessageHandlerChain();
+		chain.setBeanName("testChain");
+		chain.setHandlers(handlers);
+		chain.setBeanFactory(beanFactory);
+		Message<String> message = MessageBuilder.withPayload("test")
+				.setReplyChannelName("testChannel").build();
+		chain.handleMessage(message);
+		Message<?> reply = replyChannel.receive(0);
+		assertNotNull(reply);
+		assertEquals("test123", reply.getPayload());
+	}
+
+
+	private static MessageHandler createHandler(final int index) {
+		return new AbstractReplyProducingMessageHandler() {
+			@Override
+			protected void handleRequestMessage(Message<?> requestMessage, ReplyMessageHolder replyMessageHolder) {
+				replyMessageHolder.set(requestMessage.getPayload().toString() + index);
+			}
+		};
+	}
+
+}