该文章基于《Spring源码深度解析》撰写，感谢郝佳老师的奉献

ActiveMQ Demo

JMS作为JavaEE的规范之一，它的实现产品ActiveMQ一直占有极高的市场份额，下面通过一个小Demo来展示ActiveMQ的用法：
首先需要下载ActiveMQ，然后进入bin目录，选择32位系统或者64位系统下的activemq.bat进行运行，然后将activeMQ目录下的lib中的jar文件导入到我们的项目中，接下来我们开始编写发送端和接收端，该工程的架构如下
![这里写图片描述][Image 1]：

/*Reciver.java*/
import org.apache.activemq.ActiveMQConnectionFactory;
import javax.jms.*;
public class Reciver { 
    public static void main(String[] args) throws JMSException {
        ConnectionFactory connectionFactory = new ActiveMQConnectionFactory();
        Connection connection = connectionFactory.createConnection();
        connection.start();
        final Session session = connection.createSession(Boolean.TRUE,Session.AUTO_ACKNOWLEDGE);
        Destination destination = session.createQueue("my-queue");
        MessageConsumer consumer = session.createConsumer(destination);
        int i = 0;
        while(i < 3){
            i++;
            TextMessage message = (TextMessage) consumer.receive();
            session.commit();
            System.out.println("收到消息"+message.getText());
        }
        session.close();
        connection.close();
    }
}
/*Sender.java*/
import org.apache.activemq.ActiveMQConnectionFactory;
import javax.jms.*;
public class Sender { 
    public static void main(String[] args) throws JMSException, InterruptedException {
        ConnectionFactory connectionFactory = new ActiveMQConnectionFactory();
        Connection connection = connectionFactory.createConnection();
        Session session = connection.createSession(Boolean.TRUE,Session.AUTO_ACKNOWLEDGE);
        Destination destination = session.createQueue("my-queue");
        MessageProducer producer = session.createProducer(destination);
        for(int i = 0; i < 3; i++){
            TextMessage message = session.createTextMessage("大家好这是个测试");
            Thread.sleep(1000);
            producer.send(message);
        }
        session.commit();
        session.close();
        connection.close();
// System.out.println("good");
    }
}

先运行Sender的函数，在运行Receiver，就可以得到如下结果：
![结果][Image 1]

Spring整合ActiveMQ

项目架构如下：
![工程架构][Image 1]
其中各个文件的代码如下

<!--applicationContext-ActiveMQ.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" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.1.xsd">
    <bean id="connectionFactory" class="org.apache.activemq.ActiveMQConnectionFactory">
        <property name="brokerURL">
            <value>tcp://localhost:61616</value>
        </property>
    </bean>
    <bean id="jmstemplate" class="org.springframework.jms.core.JmsTemplate">
        <property name="connectionFactory">
            <ref bean="connectionFactory"/>
        </property>
    </bean>
    <bean id="destination" class="org.apache.activemq.command.ActiveMQQueue">
        <constructor-arg index="0">
            <value>HelloWorldQueue</value>
        </constructor-arg>
    </bean>
</beans>
<!--web.xml-->
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0">
    <display-name>Archetype Created Web Application</display-name>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
</web-app>
/*HelloWorldSender.java*/
package Sender;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.jms.core.JmsTemplate;
import javax.jms.Destination;
import java.io.File;
public class HelloWorldSender { 
    public static void main(String[] args){
        ApplicationContext context = new ClassPathXmlApplicationContext(new String[]{
   "applicationContext-ActiveMQ.xml"});
        File file = new File("/");
        System.out.println(file.getAbsolutePath());
        for(String str :context.getBeanDefinitionNames()){
            System.out.println(str);
        }
        JmsTemplate jmsTemplate = (JmsTemplate) context.getBean("jmstemplate");
        Destination destination = (Destination) context.getBean("destination");
        jmsTemplate.send(destination, session -> session.createTextMessage("大家好这是个测试"));
    }
}
/*HelloWorldReciver.java*/
package Reciver;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.jms.core.JmsTemplate;
import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.TextMessage;
public class HelloWorldReciver { 
    public static void main(String[] args) throws JMSException {
        ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext-ActiveMQ.xml");
        JmsTemplate jmsTemplate = (JmsTemplate) context.getBean("jmstemplate");
        Destination destination = (Destination) context.getBean("destination");
        TextMessage msg = (TextMessage)jmsTemplate.receive(destination);
        System.out.println("recived msg is:"+msg.getText());
    }
}

运行规则同单独使用activeMQ相同，所以此处不再赘述。
上面方法的问题在于jmsTemplate.receive(destination);只能接受一次消息，如果未接收到消息，则会一直等到。通过消息监听器可以更好的处理这个问题，下面为工程的架构
![activeMQ监听器][Image 1]
下面给出关于源代码

/*MyMessageListener.java*/
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageListener;
import javax.jms.TextMessage;
public class MyMessageListener implements MessageListener{ 
    @Override
    public void onMessage(Message message) {
        TextMessage msg = (TextMessage)message;
        try {
            System.out.println(msg.getText());
        } catch (JMSException e) {
            e.printStackTrace();
        }
    }
}
/*HelloWorldSender.java*/
package Sender;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.jms.core.JmsTemplate;
import javax.jms.Destination;
import java.io.File;
public class HelloWorldSender { 
    public static void main(String[] args){
        ApplicationContext context = new ClassPathXmlApplicationContext(new String[]{
   "applicationContext-ActiveMQ.xml"});
        JmsTemplate jmsTemplate = (JmsTemplate) context.getBean("jmstemplate");
        Destination destination = (Destination) context.getBean("destination");
        jmsTemplate.send(destination, session -> session.createTextMessage("大家好这是个测试"));
    }
}
<!--applicationContext-ActiveMQ.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" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.1.xsd">
    <bean id="connectionFactory" class="org.apache.activemq.ActiveMQConnectionFactory">
        <property name="brokerURL">
            <value>tcp://localhost:61616</value>
        </property>
    </bean>
    <bean id="jmstemplate" class="org.springframework.jms.core.JmsTemplate">
        <property name="connectionFactory">
            <ref bean="connectionFactory"/>
        </property>
    </bean>
    <bean id="destination" class="org.apache.activemq.command.ActiveMQQueue">
        <constructor-arg index="0">
            <value>HelloWorldQueue</value>
        </constructor-arg>
    </bean>
    <bean id="myTextListener" class="Listener.MyMessageListener"/>
    <bean id="javaConsumer" class="org.springframework.jms.listener.DefaultMessageListenerContainer">
        <property name="connectionFactory" ref="connectionFactory"/>
        <property name="destination" ref="destination"/>
        <property name="messageListener" ref="myTextListener"/>
    </bean>
</beans>

运行上面的代码，将会出现下面的结果
![结果][Image 1]

[Image 1]: