Question

我使用以下java应用程序将消息放在JMS队列上

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;


public class Main {
public static void main(String[] args) {
    ApplicationContext ctx = new ClassPathXmlApplicationContext("app-context.xml");
    JmsMessageSender jmsMessageSender = (JmsMessageSender)ctx.getBean("jmsMessageSender");

    java.lang.String text = "{\"name\": \"Bob\"}";
    jmsMessageSender.send(text);
    ((ClassPathXmlApplicationContext)ctx).close();
}

}

邮件发件人如下所示：

import javax.jms.Destination;
import javax.jms.JMSException;
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;
import org.springframework.stereotype.Service;

@Service
public class JmsMessageSender {
@Autowired
private JmsTemplate jmsTemplate;
public void send(final String text) {
    this.jmsTemplate.send(new MessageCreator() {
        @Override
        public Message createMessage(Session session) throws JMSException {
            Message message = session.createTextMessage(text);
            return message;
        }
    });
}


}

弹簧配置如下：

<?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:beans="http://www.springframework.org/schema/beans"
   xmlns:context="http://www.springframework.org/schema/context"
   xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd">


<context:component-scan base-package="com.intonilof" />
<bean id="amqConnectionFactory" class="org.apache.activemq.ActiveMQConnectionFactory">
    <constructor-arg index="0" value="tcp://127.0.0.1:61616" />
</bean>

<bean id="connectionFactory"
      class="org.springframework.jms.connection.CachingConnectionFactory">
    <constructor-arg ref="amqConnectionFactory" />
</bean>

<bean id="defaultDestination" class="org.apache.activemq.command.ActiveMQTopic">
    <constructor-arg index="0" value="emailsToSend" />
</bean>

<bean id="jmsTemplate" class="org.springframework.jms.core.JmsTemplate">
    <property name="connectionFactory" ref="connectionFactory" />
    <property name="defaultDestination" ref="defaultDestination" />
</bean>

如果我使用此代码将消息放在如何为将要来的主题创建消费者并在以后使用jms消息的时候？

我尝试了以下内容，但它没有消费消息：

import org.apache.activemq.command.ActiveMQTextMessage;
import org.apache.log4j.Logger;
import org.json.JSONObject;

import java.util.Date;

public class App {
final static Logger logger = Logger.getLogger(App.class);
public static void main(String[] args) throws Exception {
    thread(new HelloWorldConsumer(), false);
}

public static void thread(Runnable runnable, boolean daemon) {
    Thread brokerThread = new Thread(runnable);
    brokerThread.setDaemon(daemon);
    brokerThread.start();
}

public static class HelloWorldConsumer implements Runnable, ExceptionListener {

    public void run() {
        try {
            logger.trace("Running at: " + new Date().toString());
            ActiveMQConnectionFactory connectionFactory = new ActiveMQConnectionFactory("tcp://localhost:61616");
            Connection connection = connectionFactory.createConnection();
            connection.start();
            connection.setExceptionListener(this);
            Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
            Queue queue = session.createQueue("emailsToSend?consumer.retroactive=true");
            MessageConsumer consumer = session.createConsumer(topic);
            Message message = consumer.receive(1000);

            if (message instanceof TextMessage) {
                    System.out.println("Found message");

            } else if (message == null){
                logger.trace("No messages");
            }
            consumer.close();
            session.close();
            connection.close();
        } catch (Exception e) {
            logger.info("Caught: " + e);
            e.printStackTrace();
        }
    }

    public synchronized void onException(JMSException ex) {
        logger.trace("JMS Exception occured.  Shutting down client.");
    }
}
}

Answer 1

您需要先创建持久主题订阅。然后，当订户断开连接时，JMS将保留所有已发布的消息，并在重新连接时将其传送。

主动消耗ActiveMQ上的消息

1 个答案: