Question

我正在编写一个使用ActiveMQ发送JSON文件的JAVA应用程序。我从这个开源软件下载了这些库：http://activemq.apache.org/download.html。

应该发生的是我发送JSON文件的地方应该使用它，并且应该在屏幕上显示响应。我有另一个应用程序，但我想要另一个打印到命令行的应用程序。但是，根据我所写的内容，这种情况不会发生。看来我的代码确实连接到某个URL，但我不确定我是否正确执行此操作，因为这是我第一次使用它。有人可以确认我是否正确地这样做或者我错过了什么？

import org.apache.activemq.ActiveMQConnectionFactory;

import javax.jms.Connection;
import javax.jms.DeliveryMode;
import javax.jms.Destination;
import javax.jms.ExceptionListener;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageConsumer;
//import javax.jms.MessageProducer;
import javax.jms.Session;
import javax.jms.TextMessage;
import javax.jms.MessageProducer;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
//import java.util.Iterator;

//import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;

public class SimRunner {

static String topic = null;
static String url = null;
static String msg = null;
static String jsonFile = null;

public static void main(String[] args) throws Exception {

    JSONParser parser = new JSONParser();

    url = "tcp://localhost:45125";
    jsonFile = "c:\\example\\file.json";
    System.out.println("ActiveMQ url: " + url);
    System.out.println("JSON File: " + jsonFile);

    //read JSON file and parse/set topic
    try {
        Object obj = parser.parse(new FileReader(jsonFile));

        JSONObject jsonObject = (JSONObject) obj;
        msg = jsonObject.toJSONString().replace("\\/", "/");

        topic = ((String) jsonObject.get("topic"));
        System.out.println("Message queue/topic: " + topic);
        System.out.println("Message (from file): " + msg);

} catch (FileNotFoundException e) {
    e.printStackTrace();
} catch (IOException e) {
    e.printStackTrace();
} catch (ParseException e) {
            e.printStackTrace();
}

    thread(new Producer(), false);
    thread(new Consumer(), false);
    Thread.sleep(1000);
}

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

  public static class Producer implements Runnable {
    public void run() {
        try {
            // Create a ConnectionFactory
            ActiveMQConnectionFactory connectionFactory = new ActiveMQConnectionFactory(url);

            // Create a Connection
            Connection connection = connectionFactory.createConnection();
            connection.start();

            // Create a Session
            Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);

            // Create the destination (Topic or Queue)
            Destination destination = session.createQueue(topic);

            // Create a MessageProducer from the Session to the Topic or Queue
            MessageProducer producer = session.createProducer(destination);
            producer.setDeliveryMode(DeliveryMode.NON_PERSISTENT);

            // Create a message
            TextMessage message = session.createTextMessage(msg);

            // Tell the producer to send the message
            producer.send(message);
            System.out.println("Sent: "+ message.getText());

            // Clean up
            session.close();
            connection.close();
        }
        catch (Exception e) {
            System.out.println("Error occured in Producer. " + e);
            e.printStackTrace();
        }
    }
}

public static class Consumer implements Runnable, ExceptionListener {
    public void run() {
        try {

            // Create a ConnectionFactory
            ActiveMQConnectionFactory connectionFactory = new ActiveMQConnectionFactory(url);

            // Create a Connection
            Connection connection = connectionFactory.createConnection();
            connection.start();

            connection.setExceptionListener(this);

            // Create a Session
            Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);

            // Create the destination (Topic or Queue)
            Destination destination = session.createQueue(topic);

            // Create a MessageConsumer from the Session to the Topic or Queue
            MessageConsumer consumer = session.createConsumer(destination);

            // Wait for a message
            Message message = consumer.receive(1000);

            if (message instanceof TextMessage) {
                TextMessage textMessage = (TextMessage) message;
                String text = textMessage.getText();
                System.out.println("Received: " + text);
            } else {
                System.out.println("Received: " + message);
            }

            consumer.close();
            session.close();
            connection.close();
        } catch (Exception e) {
            System.out.println("Caught: " + e);
            e.printStackTrace();
        }
    }

    public synchronized void onException(JMSException ex) {
        System.out.println("JMS Exception occured.  Shutting down client.");
    }

}
}

Answer 1

目前还不完全清楚你在做什么，但听起来你正试图用两个客户端使用一个无效的单个队列接收相同的消息。队列只向一个客户端发送消息，因此如果您订阅了两个队列消费者，则他们将共享消息负载，而不是每个处理同一组消息。如果您希望有一个侦听器可以查看发送到队列但不会中断正常队列操作的每条消息，请尝试在ActiveMQ中使用mirrored queues。

使用ActiveMQ发送JSON文件

1 个答案: