Java中间件JMS(四)之ActiveMQ整合spring之类转换(三)

前几章都是直接发送MapMessage类型的数据,拿前面的例子来讲,如果生产者发送的是TextMessage，消费者也是必须TextMessage;如果我们自己要发送的数据不是TextMessage类型,而消费者还是TextMessage的，那该怎么办？难道每次接受后都要增加一个转换方法么？其实spring早就考虑到这种情况了。转化器在很多组件中都是必不缺少的东西Spring的MessageConverter接口提供了对消息转换的支持。

1、转换类的相关代码POJO

新建一个类MsgPoJo，就是一个简单的Pojo类。具体代码如下：

package jms.mq.spring;import java.io.Serializable;public class MsgPoJo implements Serializable{private String id;private String text;public String getId() {return id;}public void setId(String id) {this.id = id;}public String getText() {return text;}public void setText(String text) {this.text = text;}}

2.转换类的实现

新建一个类MsgConverter.java，实现MessageConverter接口。生成的代码如下

package jms.mq.spring;import javax.jms.JMSException;import javax.jms.Message;import javax.jms.Session;import javax.jms.TextMessage;import org.springframework.jms.support.converter.MessageConversionException;import org.springframework.jms.support.converter.MessageConverter;public class MsgConverter implements MessageConverter{@Overridepublic Object fromMessage(Message message) throws JMSException,MessageConversionException {if (!(message instanceof TextMessage)) {throw new MessageConversionException("Message is not TextMessage");}System.out.println("--转换接收的消息--");TextMessage textMessage = (TextMessage) message;MsgPoJo msgPojo = new MsgPoJo();String[] texts=textMessage.getText().split(",");msgPojo.setId(texts[0]);msgPojo.setText(texts[1]);return msgPojo;}@Overridepublic Message toMessage(Object object, Session session) throws JMSException,MessageConversionException {if (!(object instanceof MsgPoJo)) {throw new MessageConversionException("obj is not MsgPojo");}System.out.println("--转换发送的消息--");MsgPoJo msgPojo = (MsgPoJo) object;TextMessage textMessage = session.createTextMessage();textMessage.setText(msgPojo.getId()+","+msgPojo.getText());return  textMessage;}}

代码很简单就是做些转换，有fromMessage和toMessage两个方法,真好对应发送转换toMessage和接受转换fromMessage。此时，发送和接收消息要换成template.convertAndSend(message)；template.receiveAndConvert()。接下来我做一些配置，让spring知道我们的转换类。修改applicationContext.xml中jms模版配置的代码，修改后的代码如下：

<!-- 类转换 --><bean id="msgConverter" class="jms.mq.spring.MsgConverter"></bean><!-- 配置Jms模板 --><bean id="jmsQueueTemplate" class="org.springframework.jms.core.JmsTemplate"><property name="connectionFactory" ref="connectionFactory" /><property name="defaultDestination" ref="queueDest" /><!--<property name="receiveTimeout" value="10000" /> --><!-- 类转换 --><property name="messageConverter" ref="msgConverter"></property></bean>

注意:如果你有队列监听容器配置,配置jmsQueueTemplate和jmsTopicTemplate可能与队列容器配置冲突。

3、业务相关代码和配置

在QueueProducerService.java增加convertAndSend()方法并在其实现类中实现，实现类的代码如下：

package jms.mq.spring;import java.util.Date;import javax.jms.Destination;import javax.jms.JMSException;import javax.jms.Message;import javax.jms.Session;import javax.jms.TextMessage;import org.springframework.jms.core.JmsTemplate;import org.springframework.jms.core.MessageCreator;public class QueueProducerService{JmsTemplate jmsTemplate;Destination destination;public void send() {MessageCreator messageCreator = new MessageCreator() {public Message createMessage(Session session) throws JMSException {TextMessage message = session.createTextMessage();message.setText("QueueProducerService发送消息"+new Date());return message;}};jmsTemplate.send(this.destination,messageCreator);}public void convertAndSend(){MsgPoJo msgPojo = new MsgPoJo();msgPojo.setId("1");msgPojo.setText("first msg");System.out.println("--发送消息：msgPojo.id为"+msgPojo.getId()+"；msgPojo.text为"+msgPojo.getText());jmsTemplate.convertAndSend(this.destination, msgPojo);}public void setJmsTemplate(JmsTemplate jmsTemplate) {this.jmsTemplate = jmsTemplate;}public void setDestination(Destination destination) {this.destination = destination;}}

同样在QueueConsumerService.java中增加receiveAndConvert()方法并在其实现类中实现，实现类的代码如下：

package jms.mq.spring;import javax.jms.Destination;import javax.jms.JMSException;import javax.jms.TextMessage;import org.springframework.jms.core.JmsTemplate;public class QueueConsumerService{JmsTemplate jmsTemplate;Destination destination;public void receive() {TextMessage message = (TextMessage) jmsTemplate.receive();try {System.out.println("QueueConsumerService收到消息："+message.getText());} catch (JMSException e) {e.printStackTrace();}}public void receiveAndConvert() {MsgPoJo msgPojo = (MsgPoJo)jmsTemplate.receiveAndConvert();if(msgPojo!=null){System.out.println("--收到消息：msgPojo.id为"+msgPojo.getId()+";msgPojo.text为"+msgPojo.getText());}}public void setJmsTemplate(JmsTemplate jmsTemplate) {this.jmsTemplate = jmsTemplate;}public void setDestination(Destination destination) {this.destination = destination;}}

修改我们的两个测试类，增加对转换方法的调用，不再赘述，直接上代码：

QueueConsumerTest.java测试类

package jms.mq.spring;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;public class QueueConsumerTest {private static ApplicationContext appContext = new ClassPathXmlApplicationContext( "applicationContext.xml");private static void receive() {QueueConsumerService consumerService = (QueueConsumerService) appContext.getBean("queueConsumerService");consumerService.receive();}private static void receiveAndConvert() {QueueConsumerService consumerService = (QueueConsumerService) appContext.getBean("queueConsumerService");consumerService.receiveAndConvert();}public static void main(String[] args) {//receive();receiveAndConvert();}}

QueueProducerTest.java测试类

package jms.mq.spring;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;public class QueueProducerTest {private static ApplicationContext appContext = new ClassPathXmlApplicationContext( "applicationContext.xml");private static void send() {QueueProducerService producerService = (QueueProducerService) appContext.getBean("queueProducerService");producerService.send();}private static void convertAndSend() {QueueProducerService producerService = (QueueProducerService) appContext.getBean("queueProducerService");producerService.convertAndSend();}public static void main(String[] args) {//send();convertAndSend();}}

代码编写完毕，我们看一下我们的劳动成果。首先运行生产者类和消费者控制台信息如下：

收到的内容与发的内容相同，说明转换成功了。如果这一部分的程序使用的队列跟上面的一样，那你会发现发送的时候打印出的信息不值上面的一个，还包括一个接收的信息，这是为什么呢？了解spring原理的人应该知道，spring是把所有类都加载到内容中，当然也包括我们上门写的按个实现MessageListener的一个消费者类，他们也在运行，如果监听的地址跟你送的地址正好相同的话，他也有可能收到这个信息。所以在测试的时候要注意修改配置文件。

<bean id="queueProducerService" class="jms.mq.spring.QueueProducerService"><property name="jmsTemplate" ref="jmsQueueTemplate" /><property name="destination" ref="queueDest" />  </bean><bean id="queueConsumerService" class="jms.mq.spring.QueueConsumerService"><property name="jmsTemplate" ref="jmsQueueTemplate" /><property name="destination" ref="queueDest" /> </bean>

4、监听器上的使用方式

我再来学习一下跟监听器联合使用的方式，只在发布订阅者模式上演示一下。我们先来修改发布者的实现方式，在发布者中增加convertAndSend方法并在其实现类中实现,订阅者监听器没有类转换,不用修改，发布者修改后的代码如下：

package jms.mq.spring;import java.util.Date;import javax.jms.Destination;import javax.jms.JMSException;import javax.jms.MapMessage;import javax.jms.Message;import javax.jms.Session;import javax.jms.TextMessage;import org.springframework.jms.core.JmsTemplate;import org.springframework.jms.core.MessageCreator;import jms.spring.QueueProducerService;public class TopicPublisherService{JmsTemplate jmsTemplate; Destination destination;public void send() {MessageCreator messageCreator = new MessageCreator() {public Message createMessage(Session session) throws JMSException {TextMessage message = session.createTextMessage();message.setText("QueueProducerService发送消息"+new Date());return message;}};jmsTemplate.send(this.destination,messageCreator);}public void convertAndSend(Object obj) {System.out.println("--发送PoJo对象...");jmsTemplate.convertAndSend(destination, obj);}public void setJmsTemplate(JmsTemplate jmsTemplate) {this.jmsTemplate = jmsTemplate;}public void setDestination(Destination destination) {this.destination = destination;}}

发布订阅者配置文件如下

<!-- 配置TopicJms模板 --><bean id="jmsTopicTemplate" class="org.springframework.jms.core.JmsTemplate"><property name="connectionFactory" ref="connectionFactory" /><property name="defaultDestination" ref="topicDest" /><!-- 配置是否为发布订阅者模式，默认为false --><property name="pubSubDomain" value="true" /><!--<property name="receiveTimeout" value="10000" /> --><property name="messageConverter" ref="msgConverter"></property></bean>

<bean id="topicPublisherService" class="jms.mq.spring.TopicPublisherService"><property name="jmsTemplate" ref="jmsTopicTemplate" /><!-- <property name="destination" ref="topicDest" /> --><property name="destination" ref="topicSubscriberMessageListenerDest" /> </bean><bean id="topicSubscriberService" class="jms.mq.spring.TopicSubscriberService"><property name="jmsTemplate" ref="jmsTopicTemplate" /><property name="destination" ref="topicDest" /></bean>

修改上面的发布测试类，修改增加对新增方法的调用，修改后的内容如下：

package jms.mq.spring;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;public class TopicPublisherTest {private static ApplicationContext appContext = new ClassPathXmlApplicationContext( "applicationContext.xml");private static void send() {TopicPublisherService topicPublisherService = (TopicPublisherService) appContext.getBean("topicPublisherService");topicPublisherService.send();}private static void convertAndSend() {TopicPublisherService topicPublisherService = (TopicPublisherService) appContext.getBean("topicPublisherService");MsgPoJo msgPoJo = new MsgPoJo();msgPoJo.setId("1");msgPoJo.setText("测试内容");topicPublisherService.convertAndSend(msgPoJo);}public static void main(String[] args) {//send();convertAndSend();}}

运行发布测试类,运行结果如下：

写在到这里,ActiveMQ与spring整合就讲完了，主要讲了ActiveMQ与spring的简单整合,监听器和类转换这些主要功能.

呵呵，写到不好,请大家不要拍砖。