TcpServerConnectionDeserializeTest.java

/*
 * Copyright 2002-2012 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.samples.tcpclientserver;

import static org.junit.Assert.assertEquals;

import java.io.StringWriter;

import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.messaging.SubscribableChannel;
import org.springframework.integration.handler.AbstractReplyProducingMessageHandler;
import org.springframework.integration.ip.tcp.connection.AbstractServerConnectionFactory;
import org.springframework.integration.ip.tcp.serializer.ByteArrayStxEtxSerializer;
import org.springframework.integration.ip.util.TestingUtilities;
import org.springframework.integration.samples.tcpclientserver.support.CustomTestContextLoader;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageChannel;
import org.springframework.test.annotation.DirtiesContext;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

/**
 * Shows an example of using the Stx/Etx stream framing serializers that are included with
 * Spring Integration. We can be confident that the streams are properly handled because we
 * explicitly send a stream with the Stx/Etx frame and the beginning and end of the actual
 * content and the Server is configured to be able to handle the frame. In the asserts, we
 * assert that the payload, once it reaches a component (in this case, the message listener
 * we create and attach to the incomingServerChannel), does not have any of the Stx/Etx bytes.
 *
 * @author Christian Posta
 * @author Gunnar Hillert
 */
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(loader=CustomTestContextLoader.class,
	locations = {"/META-INF/spring/integration/tcpServerConnectionDeserialize-context.xml"})
@DirtiesContext
public class TcpServerConnectionDeserializeTest {

	@Autowired
	SimpleGateway gw;

	@Autowired
	@Qualifier("incomingServerChannel")
	MessageChannel incomingServerChannel;

	@Autowired
	AbstractServerConnectionFactory crLfServer;

	@Before
	public void setup() {
		TestingUtilities.waitListening(this.crLfServer, 10000L);
	}

	@Test
	public void testHappyPath() {

		// add a listener to this channel, otherwise there is not one defined
		// the reason we use a listener here is so we can assert truths on the
		// message and/or payload
		SubscribableChannel channel = (SubscribableChannel) incomingServerChannel;
		channel.subscribe(new AbstractReplyProducingMessageHandler() {

			@Override
			protected Object handleRequestMessage(Message<?> requestMessage) {
				byte[] payload = (byte[]) requestMessage.getPayload();

				// we assert during the processing of the messaging that the
				// payload is just the content we wanted to send without the
				// framing bytes (STX/ETX)
				assertEquals("Hello World!", new String(payload));
				return requestMessage;
			}
		});

		String sourceMessage = wrapWithStxEtx("Hello World!");
		String result = gw.send(sourceMessage);
		System.out.println(result);
		assertEquals("Hello World!", result);
	}

	/**
	 * Show, explicitly, how the stream would look if you had to manually create it.
	 *
	 * See more about TCP synchronous communication for more about framing the stream
	 * with STX/ETX:  http://en.wikipedia.org/wiki/Binary_Synchronous_Communications
	 *
	 * @param content
	 * @return a string that is wrapped with the STX/ETX framing bytes
	 */
	private String wrapWithStxEtx(String content) {
		StringWriter writer = new StringWriter();
		writer.write(ByteArrayStxEtxSerializer.STX);
		writer.write(content);
		writer.write(ByteArrayStxEtxSerializer.ETX);
		return writer.toString();
	}
}