使用 ActiveMQ 庫進行訊息傳遞（activemq jms 提供程式特定實現）

設定 ActiveMQ

• 從 activemq.apache.org 下載 ActiveMQ 發行版並在某處解壓縮
• 你可以使用指令碼 bin / activemq 立即啟動伺服器，在 localhost 上執行不安全
• 當它執行時，你可以在 http：// localhost：8161 / admin / 上訪問本地伺服器的控制檯
• 通過修改 conf / activemq.xml 來配置它
• 正如標題所示，以下示例使用者 activemq jms 提供程式特定的實現，因此需要將 activemq-all.jar 新增到類路徑中。

通過獨立客戶端傳送訊息

import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageProducer;
import javax.jms.Queue;
import javax.jms.Session;
import org.apache.activemq.ActiveMQConnectionFactory;

public class JmsClientMessageSender {

    public static void main(String[] args) {
        ConnectionFactory factory = new ActiveMQConnectionFactory("tcp://localhost:61616"); // ActiveMQ-specific
        Connection con = null;
        try {
            con = factory.createConnection();
            Session session = con.createSession(false, Session.AUTO_ACKNOWLEDGE); // non-transacted session

            Queue queue = session.createQueue("test.queue"); // only specifies queue name

            MessageProducer producer = session.createProducer(queue);
            Message msg = session.createTextMessage("hello queue"); // text message
            producer.send(msg);

        } catch (JMSException e) {
            e.printStackTrace();
        } finally {
            if (con != null) {
                try {
                    con.close(); // free all resources
                } catch (JMSException e) { /* Ignore */ }
            }
        }
    }
}

輪詢訊息

import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageConsumer;
import javax.jms.Queue;
import javax.jms.Session;
import javax.jms.TextMessage;
import org.apache.activemq.ActiveMQConnectionFactory;

public class JmsClientMessagePoller {

    public static void main(String[] args) {
        ConnectionFactory factory = new ActiveMQConnectionFactory("tcp://localhost:61616"); // ActiveMQ-specific
        Connection con = null;

        try {
            con = factory.createConnection();
            Session session = con.createSession(false, Session.AUTO_ACKNOWLEDGE); // non-transacted session

            Queue queue = session.createQueue("test.queue"); // only specifies queue name

            MessageConsumer consumer = session.createConsumer(queue);

            con.start(); // start the connection
            while (true) { // run forever
                Message msg = consumer.receive(); // blocking!
                if (!(msg instanceof TextMessage))
                    throw new RuntimeException("Expected a TextMessage");
                TextMessage tm = (TextMessage) msg;
                System.out.println(tm.getText()); // print message content
            }
        } catch (JMSException e) {
            e.printStackTrace();
        } finally {
            try {
                con.close();
            } catch (JMSException e) {/* Ignore */ }
        }
    }
}

使用 MessageListener

import javax.jms.Connection;
import javax.jms.ConnectionFactory;
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;

public class JmsClientMessageListener {

    public static void main(String[] args) {
        ConnectionFactory factory = new ActiveMQConnectionFactory("tcp://localhost:61616"); // ActiveMQ-specific
        Connection con = null;

        try {
            con = factory.createConnection();
            Session session = con.createSession(false, Session.AUTO_ACKNOWLEDGE); // non-transacted session
            Queue queue = session.createQueue("test.queue"); // only specifies queue name

            MessageConsumer consumer = session.createConsumer(queue);

            consumer.setMessageListener(new MessageListener() {
                public void onMessage(Message msg) {
                    try {
                        if (!(msg instanceof TextMessage))
                            throw new RuntimeException("no text message");
                        TextMessage tm = (TextMessage) msg;
                        System.out.println(tm.getText()); // print message
                    } catch (JMSException e) {
                        System.err.println("Error reading message");
                    }
                }
            });
            con.start(); // start the connection
            Thread.sleep(60 * 1000); // receive messages for 60s
        } catch (JMSException e1) {
            e1.printStackTrace();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            try {
                con.close();        // free all resources
            } catch (JMSException e) {
                e.printStackTrace();
            } 
        }
    }
}