Spring提供的JmsTemplate对原生的JMS API进行了一层薄薄的封装,使用起来非常的方便。
我使用的JMS消息代理插件是Apache的ActiveMQ,建议安装最新版本,因为我之前安装老版本,各种不兼容,各种bug,最新版的activemq-all-5.9.1.jar包里面已经有了slf4j.impl包,之前就是被这个坑了...把这个jar包加到lib目录下面,就不会有各种ClassNotFound异常和类冲突的bug了。
下载ActiveMQ解压之后运行bin下面的activemq.bat就可以运行了。你可以访问http://127.0.0.1:8161/看看服务是否正常开启
默认账户密码是admin/admin
下面这个例子是一个邮局系统,包括前后台两个子系统,当前台收到一封邮件的时候,它将这封邮件传递给后台,同时发送一个JMS消息给后台子系统,提醒新的邮件。
JMS有两种消息通信模型:
1)、point-to-point
2)、pub/sub
这里我们当然是用的第一种模型.
首先我们建立一个Mail类:
package com.apress.springrecipes.post; public class Mail { private String mailId; private String country; private double weight; public Mail() { } public Mail(String mailId, String country, double weight) { this.mailId = mailId; this.country = country; this.weight = weight; } public String getMailId() { return mailId; } public void setMailId(String mailId) { this.mailId = mailId; } public String getCountry() { return country; } public void setCountry(String country) { this.country = country; } public double getWeight() { return weight; } public void setWeight(double weight) { this.weight = weight; } }
一个前台子系统接口:
package com.apress.springrecipes.post; public interface FrontDesk { public void sendMail(Mail mail); }
和它的实现类:
package com.apress.springrecipes.post; import javax.jms.Destination; import javax.jms.JMSException; import javax.jms.MapMessage; import javax.jms.Message; import javax.jms.Session; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.jms.core.JmsTemplate; import org.springframework.jms.core.MessageCreator; public class FrontDeskImpl2 implements FrontDesk { @Autowired private JmsTemplate jmsTemplate; @Autowired private Destination destination; @Override public void sendMail(final Mail mail) { jmsTemplate.send(destination,new MessageCreator() { @Override public Message createMessage(Session session) throws JMSException { MapMessage message = session.createMapMessage(); message.setString("mailId", mail.getMailId()); message.setString("country", mail.getCountry()); message.setDouble("weight", mail.getWeight()); return message; } }); } }
一个后台子系统的接口:
package com.apress.springrecipes.post; public interface BackOffice { public Mail receiveMail(); }
和它的实现类:
package com.apress.springrecipes.post; import javax.jms.Destination; import javax.jms.JMSException; import javax.jms.MapMessage; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.jms.core.JmsTemplate; import org.springframework.jms.support.JmsUtils; public class BackOfficeImpl2 implements BackOffice { @Autowired private JmsTemplate jmsTemplate; @Autowired private Destination destination; @Override public Mail receiveMail() { MapMessage message = (MapMessage) jmsTemplate.receive(destination); try { if (message == null) { return null; } Mail mail = new Mail(); mail.setMailId(message.getString("mailId")); mail.setCountry(message.getString("country")); mail.setWeight(message.getDouble("weight")); return mail; } catch (JMSException e) { throw JmsUtils.convertJmsAccessException(e); } } }
前台子系统的xml配置文件bean-front.xml:
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd"> <context:annotation-config/> <bean id="frontDesk" class="com.apress.springrecipes.post.FrontDeskImpl2" /> <bean id="connectionFactory" class="org.apache.activemq.ActiveMQConnectionFactory"> <property name="brokerURL" value="tcp://localhost:61616"/> </bean> <bean id="destination" class="org.apache.activemq.command.ActiveMQQueue"> <constructor-arg value="mail.queue" /> </bean> <bean id="jmsTemplate" class="org.springframework.jms.core.JmsTemplate"> <property name="connectionFactory" ref="connectionFactory"/> </bean> </beans>
后台子系统的xml配置文件bean-back.xml:
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd"> <context:annotation-config /> <bean id="backOffice" class="com.apress.springrecipes.post.BackOfficeImpl2" /> <bean id="connectionFactory" class="org.apache.activemq.ActiveMQConnectionFactory"> <property name="brokerURL" value="tcp://localhost:61616" /> </bean> <bean id="destination" class="org.apache.activemq.command.ActiveMQQueue"> <constructor-arg value="mail.queue" /> </bean> <bean id="jmsTemplate" class="org.springframework.jms.core.JmsTemplate"> <property name="connectionFactory" ref="connectionFactory" /> <property name="receiveTimeout" value="10000" /> </bean> </beans>
两个测试类,一个是发消息,一个是接受消息。
package com.apress.springrecipes.post; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; public class FrontDeskMain { public static void main(String[] args) { ApplicationContext context = new ClassPathXmlApplicationContext("beans-front.xml"); FrontDesk frontDesk = (FrontDesk) context.getBean("frontDesk"); frontDesk.sendMail(new Mail("1234","US",1.5)); } }
package com.apress.springrecipes.post; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; public class BackOfficeMain { public static void main(String[] args) { ApplicationContext context = new ClassPathXmlApplicationContext("beans-back.xml"); BackOffice backOffice = (BackOffice) context.getBean("backOffice"); Mail mail = backOffice.receiveMail(); System.out.println("Mail #" + mail.getMailId() + " received"); } }
运行FrontDeskMain之后,发送消息你可以简单的通过访问http://127.0.0.1:8161/admin/queueGraph.jsp和http://127.0.0.1:8161/admin/queues.jsp观察发生的情况。再运行BackOfficeMain观察这两个页面的变化。
时间: 2024-11-05 18:50:30