啟動生產者：

如果這時候我刪除一個訊息，然後啟動消費者：

訊息消費完了 再一次啟動消費者並不會消費。

程式碼是看別人的：

package com.haibo.ActiveMq;


import org.apache.activemq.ActiveMQConnection;
import org.apache.activemq.ActiveMQConnectionFactory;

import javax.jms.*;

/**
 * Created by liuhaibo on 18/9/16.
 */
public class JMSProducer {
    //預設連線使用者名稱
    private static final String USERNAME = ActiveMQConnection.DEFAULT_USER;
    //預設連線密碼
    private static final String PASSWORD = ActiveMQConnection.DEFAULT_PASSWORD;
    //預設連線地址
    private static final String BROKEURL = ActiveMQConnection.DEFAULT_BROKER_URL;
    //傳送的訊息數量
    private static final int SENDNUM = 10;

    public static void main(String[] args) {
        //連線工廠
        ConnectionFactory connectionFactory;
        //連線
        Connection connection = null;
        //會話 接受或者傳送訊息的執行緒
        Session session;
        //訊息的目的地
        Destination destination;
        //訊息生產者
        MessageProducer messageProducer;
        //例項化連線工廠
        connectionFactory = new ActiveMQConnectionFactory(JMSProducer.USERNAME, JMSProducer.PASSWORD, JMSProducer.BROKEURL);

        try {
            //通過連線工廠獲取連線
            connection = connectionFactory.createConnection();
            //啟動連線
            connection.start();
            //建立session
            session = connection.createSession(true, Session.AUTO_ACKNOWLEDGE);
            //建立一個名稱為HelloWorld的訊息佇列
            destination = session.createQueue("HelloWorld");
            //建立訊息生產者
            messageProducer = session.createProducer(destination);
            //傳送訊息
            sendMessage(session, messageProducer);

            session.commit();

        } catch (Exception e) {
            e.printStackTrace();
        }finally{
            if(connection != null){
                try {
                    connection.close();
                } catch (JMSException e) {
                    e.printStackTrace();
                }
            }
        }

    }
    /**
     * 傳送訊息
     * @param session
     * @param messageProducer  訊息生產者
     * @throws Exception
     */
    public static void sendMessage(Session session,MessageProducer messageProducer) throws Exception{
        for (int i = 0; i < JMSProducer.SENDNUM; i++) {
            //建立一條文字訊息
            TextMessage message = session.createTextMessage("ActiveMQ 傳送訊息" +i);
            System.out.println("傳送訊息：Activemq 傳送訊息" + i);
            //通過訊息生產者發出訊息
            messageProducer.send(message);
        }

    }
}

 

package com.haibo.ActiveMq;

import org.apache.activemq.ActiveMQConnection;
import org.apache.activemq.ActiveMQConnectionFactory;

import javax.jms.*;

/**
 * Created by liuhaibo on 18/9/17.
 */
public class JMSConsumer {
    private static final String USERNAME = ActiveMQConnection.DEFAULT_USER;//預設連線使用者名稱
    private static final String PASSWORD = ActiveMQConnection.DEFAULT_PASSWORD;//預設連線密碼
    private static final String BROKEURL = ActiveMQConnection.DEFAULT_BROKER_URL;//預設連線地址

    public static void main(String[] args) {
        ConnectionFactory connectionFactory;//連線工廠
        Connection connection = null;//連線

        Session session;//會話 接受或者傳送訊息的執行緒
        Destination destination;//訊息的目的地

        MessageConsumer messageConsumer;//訊息的消費者

        //例項化連線工廠
        connectionFactory = new ActiveMQConnectionFactory(JMSConsumer.USERNAME, JMSConsumer.PASSWORD, JMSConsumer.BROKEURL);

        try {
            //通過連線工廠獲取連線
            connection = connectionFactory.createConnection();
            //啟動連線
            connection.start();
            //建立session
            session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
            //建立一個連線HelloWorld的訊息佇列
            destination = session.createQueue("HelloWorld");
            //建立訊息消費者
            messageConsumer = session.createConsumer(destination);

            while (true) {
                TextMessage textMessage = (TextMessage) messageConsumer.receive(100000);
                if(textMessage != null){
                    System.out.println("收到的訊息:" + textMessage.getText());
                }else {
                    break;
                }
            }

        } catch (JMSException e) {
            e.printStackTrace();
        }

    }
}