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标题: JavaEE的13种核心技术规范-JMS(4) [打印本页]

作者: li745547 时间: 2018-3-25 14:22
标题: JavaEE的13种核心技术规范-JMS(4)

import javax.jms.Connection;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageConsumer;
import javax.jms.MessageListener;
import javax.jms.Queue;
import javax.jms.Session;
import javax.jms.TextMessage;
import org.apache.activemq.ActiveMQConnectionFactory;
import org.apache.activemq.command.ActiveMQQueue;
public class DeliveryModeReceiveTest {
public staticvoid main(String[] args)throws Exception {
ActiveMQConnectionFactory factory = newActiveMQConnectionFactory("vm://localhost");
Connection connection = factory.createConnection();
connection.start();
Queue queue = new ActiveMQQueue("testQueue");
Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
MessageConsumer comsumer = session.createConsumer(queue);
comsumer.setMessageListener(new MessageListener(){
public void onMessage(Message m) {
try {
System.out.println("Consumer get " + ((TextMessage)m).getText());
} catch (JMSException e) {
e.printStackTrace();
}
}
});
}
}

import javax.jms.Connection;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageConsumer;
import javax.jms.MessageListener;
import javax.jms.Queue;
import javax.jms.Session;
import javax.jms.TextMessage;
import org.apache.activemq.ActiveMQConnectionFactory;
import org.apache.activemq.command.ActiveMQQueue;
public class DeliveryModeReceiveTest {
public static void main(String[] args) throws Exception {
ActiveMQConnectionFactory factory = new ActiveMQConnectionFactory("vm://localhost");
Connection connection = factory.createConnection();
connection.start();
Queue queue = new ActiveMQQueue("testQueue");
Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
MessageConsumer comsumer = session.createConsumer(queue);
comsumer.setMessageListener(new MessageListener(){
public void onMessage(Message m) {
try {
System.out.println("Consumer get " + ((TextMessage)m).getText());
} catch (JMSException e) {
e.printStackTrace();
}
}
});
}
}

运行上面的程序，可以得到下面的输出结果：

Consumer get A persistent Message

可以看出消息消费者只接收到一个消息，它是一个Persistent的消息。而刚才发送的non persistent消息已经丢失了。

另外, 如果发送一个non persistent消息, 而刚好这个时候没有消费者在监听, 这个消息也会丢失.

深入掌握JMS（八）：JMSReplyTo

在下面的例子中，首先创建两个Queue，发送者给一个Queue发送，接收者接收到消息之后给另一个Queue回复一个Message，然后再创建一个消费者来接受所回复的消息。
[java] view plaincopy

import javax.jms.Connection;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageConsumer;
import javax.jms.MessageListener;
import javax.jms.MessageProducer;
import javax.jms.Queue;
import javax.jms.Session;
import javax.jms.TextMessage;
import org.apache.activemq.ActiveMQConnectionFactory;
import org.apache.activemq.command.ActiveMQQueue;
public class MessageSendReceiveAndReply {
public staticvoid main(String[] args)throws Exception {
ActiveMQConnectionFactory factory = newActiveMQConnectionFactory("vm://localhost");
Connection connection = factory.createConnection();
connection.start();
//消息发送到这个Queue
Queue queue = new ActiveMQQueue("testQueue");
//消息回复到这个Queue
Queue replyQueue = new ActiveMQQueue("replyQueue");
final Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
//创建一个消息，并设置它的JMSReplyTo为replyQueue。
Message message = session.createTextMessage("Andy");
message.setJMSReplyTo(replyQueue);
MessageProducer producer = session.createProducer(queue);
producer.send(message);
//消息的接收者
MessageConsumer comsumer = session.createConsumer(queue);
comsumer.setMessageListener(new MessageListener(){
public void onMessage(Message m) {
try {
//创建一个新的MessageProducer来发送一个回复消息。
MessageProducer producer = session.createProducer(m.getJMSReplyTo());
producer.send(session.createTextMessage("Hello " + ((TextMessage) m).getText()));
} catch (JMSException e1) {
e1.printStackTrace();
}
}
});
//这个接收者用来接收回复的消息
MessageConsumer comsumer2 = session.createConsumer(replyQueue);
comsumer2.setMessageListener(new MessageListener(){
public void onMessage(Message m) {
try {
System.out.println(((TextMessage) m).getText());
} catch (JMSException e) {
e.printStackTrace();
}
}
});
}
}

作者: Yin灬Yan 时间: 2018-3-25 19:04
我来占层楼啊

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