JMS

首先需要下载ActiveMQ，下面的链接给我们列出了所有版本：http://activemq.apache.org/download-archives.html每个版本为不同的OS提供了链接：

公司电脑是windows的，用目录下的activemq.bat启动：

端口号默认是61616，可以在conf/activemq.xml中看到:

<transportConnectors>    <!-- DOS PRotection, limit concurrent connections to 1000 and frame size to 100MB -->    <transportConnector name="openwire" uri="tcp://0.0.0.0:61616?maximumConnections=1000&amp;wireFormat.maxFrameSize=104857600"/>    <transportConnector name="amqp" uri="amqp://0.0.0.0:5672?maximumConnections=1000&amp;wireFormat.maxFrameSize=104857600"/>    <transportConnector name="stomp" uri="stomp://0.0.0.0:61613?maximumConnections=1000&amp;wireFormat.maxFrameSize=104857600"/>    <transportConnector name="mqtt" uri="mqtt://0.0.0.0:1883?maximumConnections=1000&amp;wireFormat.maxFrameSize=104857600"/>    <transportConnector name="ws" uri="ws://0.0.0.0:61614?maximumConnections=1000&amp;wireFormat.maxFrameSize=104857600"/></transportConnectors>

相关的Maven dependency：

<dependency>    <groupId>javax.jms</groupId>    <artifactId>javax.jms-api</artifactId>    <version>2.0</version></dependency><dependency>    <groupId>org.apache.activemq</groupId>    <artifactId>activemq-core</artifactId>    <version>5.7.0</version></dependency>

使用javax.jms.session跟JMS Provider通信:

ConnectionFactory connectionFactory = new ActiveMQConnectionFactory(        ActiveMQConnection.DEFAULT_USER,        ActiveMQConnection.DEFAULT_PASSWord, "tcp://localhost:61616");                                                                                                                                                Connection connection = connectionFactory.createConnection();connection.start();                                                                                                                                                Session session = connection.createSession(Boolean.TRUE,        Session.AUTO_ACKNOWLEDGE);

然后一些目的地、发送者、发送内容什么的都是由session来弄的：

Destination destination = session.createQueue("this is sparta!!");MessageProducer producer = session.createProducer(destination);TextMessage message0 = session.createTextMessage("这是斯巴达!!!");TextMessage message1 = session.createTextMessage("这也是斯巴达!!!");TextMessage message2 = session.createTextMessage("这些都是斯巴达!!!");producer.send(message0);producer.send(message1);producer.send(message2);session.commit();

有了producer，相应地也有consumer，接收消息方法如下：

MessageConsumer consumer = session.createConsumer(destination);System.out.println(((TextMessage) consumer.receive(10000)).getText());

结果还是consumer去一个个receive了，就像是接收人亲自去确认那样。或许我们可以让Listener代劳:

consumer.setMessageListener(new MessageListener() {    public void onMessage(Message message) {        try {            System.out.println("listener catched:::"+((TextMessage)message).getText());        } catch (JMSException e) {            e.printStackTrace();        }    }});

当这个consumer设置了Listener的时候就不能再以receive()的方式接收了,不然会出现javax.jms.IllegalStateException:Cannot synchronously receive a message when a MessageListener is set

如果想使用publish/subscribe，直接将createQueue改为createTopic即可，但需要理解Topic是无状态的。

完整code如下，发送者：

{        ConnectionFactory connectionFactory = new ActiveMQConnectionFactory(                ActiveMQConnection.DEFAULT_USER,                ActiveMQConnection.DEFAULT_PASSWORD, "tcp://localhost:61616");        Connection connection = connectionFactory.createConnection();        connection.start();                                                                                                                                                                                                                                                                    Session session = connection.createSession(Boolean.TRUE,                Session.AUTO_ACKNOWLEDGE);                                                                                                                                                                                                                                                                    Destination destination = session.createQueue("this is sparta!!");                                                                                                                                                                                                                                                                    MessageProducer producer = session.createProducer(destination);        TextMessage message0 = session.createTextMessage("这是斯巴达!!!");        TextMessage message1 = session.createTextMessage("这也是斯巴达!!!");        TextMessage message2 = session.createTextMessage("这些都是斯巴达!!!");        producer.send(message0);        producer.send(message1);        producer.send(message2);                                                                                                                                                                                                                                                                    session.commit();    }

接收者：

{        ConnectionFactory connectionFactory = new ActiveMQConnectionFactory(                ActiveMQConnection.DEFAULT_USER,                ActiveMQConnection.DEFAULT_PASSWORD, "tcp://localhost:61616");;        Connection connection = connectionFactory.createConnection();        connection.start();                                                                                                                                                                                                                                                                Session session = connection.createSession(Boolean.FALSE,                Session.AUTO_ACKNOWLEDGE);                                                                                                                                                                                                                                                                Destination destination = session.createQueue("this is sparta!!");        MessageConsumer consumer = session.createConsumer(destination);        System.out.println(((TextMessage) consumer.receive(10000)).getText());        System.out.println(((TextMessage) consumer.receive(10000)).getText());        System.out.println(((TextMessage) consumer.receive(10000)).getText());    }