JMS系列(三)-java操做JMS Topic實例

時間 2019-12-04

標籤 jms 系列 java topic 實例欄目 Java 简体版

原文原文鏈接

在上一篇介紹如何經過java往jms消息隊列裏面寫消息和讀取消息，本文介紹如何經過java往jms主題裏寫消息和讀取消息。java

消息發佈

一樣將消息發佈到主題中，須要通過如下步驟web

鏈接jms服務器
獲取鏈接工廠(Connection Factory)
經過鏈接工廠建立主題鏈接（TopicConnection)
經過主題鏈接建立主題會話（TopicSession)
經過主題會話建立主題發佈者（Publisher)
建立消息(Message)
經過發佈者將消息發送到主題中

代碼實現：segmentfault

package asan.demo.jms;

import java.util.Hashtable;
import javax.jms.JMSException;
import javax.jms.Session;
import javax.jms.TextMessage;
import javax.jms.Topic;
import javax.jms.TopicConnection;
import javax.jms.TopicConnectionFactory;
import javax.jms.TopicPublisher;
import javax.jms.TopicSession;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;

public class JMSTopicSender {
    private TopicPublisher sender = null;
    private TopicSession session = null;
    private static final String JMS_FACTORY_JNDI = "jms/jms_test_connection_factory1";
    private static final String JMS_TOPIC_JNDI = "jms/jms_test_topic";

    public JMSTopicSender() {
        super();
    }

    public void sendMessage(String msg) {
        TextMessage textMsg;
        try {
            if (this.sender == null) {
                this.init();
            }
            textMsg = session.createTextMessage();
            textMsg.setText(msg);
            sender.send(textMsg);
        } catch (JMSException e) {
            e.printStackTrace();
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }
    //    1. 鏈接jms服務器
    //    2. 獲取鏈接工廠(Connection Factory)
    //    3. 經過鏈接工廠建立主題鏈接（TopicConnection)
    //    4. 經過主題鏈接建立主題會話（TopicSession)
    //    5. 經過主題會話建立主題發佈者（Publisher)
    //    6. 建立消息(Message)
    //    7. 經過發佈者將消息發送到主題中
    private void init() throws NamingException, JMSException {
        Hashtable properties = new Hashtable();
        properties.put(Context.INITIAL_CONTEXT_FACTORY,
                       "weblogic.jndi.WLInitialContextFactory");
        properties.put(Context.PROVIDER_URL, "t3://127.0.0.1:7101");
        properties.put(Context.SECURITY_PRINCIPAL, "weblogic");
        properties.put(Context.SECURITY_CREDENTIALS, "weblogic1");
        InitialContext ctx = new InitialContext(properties);
        TopicConnectionFactory jmsFactory =
            (TopicConnectionFactory)ctx.lookup(JMS_FACTORY_JNDI);
        TopicConnection jmsConn = jmsFactory.createTopicConnection();
        session = jmsConn.createTopicSession(false, Session.AUTO_ACKNOWLEDGE);
        Topic topic = (Topic)ctx.lookup(JMS_TOPIC_JNDI);
        sender = session.createPublisher(topic);
    }
    
    public static void main(String[]cmd){
        JMSTopicSender sender=new JMSTopicSender();
        sender.sendMessage("hello jms topic");
    }
}

與隊列不一樣的是，此時主題沒有訂閱者，那麼該消息就不存儲在主題中，即便後面有訂閱者訂閱了該主題，也沒法接收訂閱前的消息。bash

消息訂閱

從主題中訂閱消息，須要通過如下步驟：服務器

鏈接jms服務器
獲取鏈接工廠(Connection Factory)
經過鏈接工廠建立主題鏈接（TopicConnection)
經過主題鏈接建立主題會話（TopicSession)
經過主題會話建立訂閱者（Subscriber)
接收消息(Message)

代碼實現：session

package asan.demo.jms;

import java.util.Hashtable;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.Session;
import javax.jms.TextMessage;
import javax.jms.Topic;
import javax.jms.TopicConnection;
import javax.jms.TopicConnectionFactory;
import javax.jms.TopicSession;
import javax.jms.TopicSubscriber;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;

public class JMSTopicReciver {
    private TopicSubscriber reciver = null;
    private static final String JMS_FACTORY_JNDI = "jms/jms_test_connection_factory1";
    private static final String JMS_TOPIC_JNDI = "jms/jms_test_topic";
    public JMSTopicReciver() {
        super();
    }
    public void reciveMessage() {
        try {
            if (this.reciver == null) {
                this.init();
            }
            System.out.println("waiting to recive message from jms topic "+JMS_TOPIC_JNDI);
            while(true){
                Message msg=reciver.receive();
                if(msg instanceof TextMessage){
                    TextMessage textMsg=(TextMessage)msg;
                    System.out.println("recive jms message:"+textMsg.getText());
                }
            }
        } catch (JMSException e) {
            e.printStackTrace();
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }
    //    1. 鏈接jms服務器
    //    2. 獲取鏈接工廠(Connection Factory)
    //    3. 經過鏈接工廠建立主題鏈接（TopicConnection)
    //    4. 經過主題鏈接建立主題會話（TopicSession)
    //    5. 經過主題會話建立訂閱者（Subscriber)
    //    6. 接收消息(Message)
    private void init() throws NamingException, JMSException {
        Hashtable properties = new Hashtable();
        properties.put(Context.INITIAL_CONTEXT_FACTORY,
                       "weblogic.jndi.WLInitialContextFactory");
        properties.put(Context.PROVIDER_URL, "t3://127.0.0.1:7101");
        properties.put(Context.SECURITY_PRINCIPAL, "weblogic");
        properties.put(Context.SECURITY_CREDENTIALS, "weblogic1");
        InitialContext ctx = new InitialContext(properties);
        TopicConnectionFactory jmsFactory =
            (TopicConnectionFactory)ctx.lookup(JMS_FACTORY_JNDI);
        TopicConnection jmsConn = jmsFactory.createTopicConnection();
        TopicSession session = jmsConn.createTopicSession(false, Session.AUTO_ACKNOWLEDGE);
        Topic topic = (Topic)ctx.lookup(JMS_TOPIC_JNDI);
        reciver = session.createSubscriber(topic);
        jmsConn.start();
    }
    
    public static void main(String[]cmd){
        JMSTopicReciver consumer=new JMSTopicReciver();
        consumer.reciveMessage();
    }
}

運行代碼，此時運行以前消息發佈的代碼，能夠在控制檯看到發送的消息dom

一樣，稍微修改下上一篇文章的客戶端程序，使整個過程看起來更清晰，修改後的客戶端代碼以下：this

package asan.demo.jms;

import java.util.Scanner;

public class JMSClient {
    public JMSClient() {
        super();
    }

    public static void help() {
        System.out.println("Usage:java -jar JMSClient.jar sender/reciver/topicSender/topicReciver");
        System.out.println("sender:向jms隊列發送消息");
        System.out.println("reciver:從隊列中取出消息");
        System.out.println("topicSender:向jms主題發送消息");
        System.out.println("topicReciver:從主題中取出消息");
    }

    public static void main(String[] cmd) {
        if (cmd.length == 0) {
            help();
            return;
        }
        String mode = cmd[0];
        if ("sender".equalsIgnoreCase(mode)) {
            JMSSender sender = new JMSSender();
            Scanner sc = new Scanner(System.in);
            while (true) {
                System.out.println("input you message(input end to exist):");
                String msg = sc.nextLine();
                if ("end".equalsIgnoreCase(msg)) {
                    return;
                }
                sender.sendMessage(msg);
                System.out.println("message send success");
            }
        } else if ("reciver".equalsIgnoreCase(mode)) {
            JMSReciver consumer = new JMSReciver();
            consumer.reciveMessage();
        } else if ("topicSender".equalsIgnoreCase(mode)) {
            JMSTopicSender sender = new JMSTopicSender();
            Scanner sc = new Scanner(System.in);
            while (true) {
                System.out.println("input you message(input end to exist):");
                String msg = sc.nextLine();
                if ("end".equalsIgnoreCase(msg)) {
                    return;
                }
                sender.sendMessage(msg);
                System.out.println("message send success");
            }
        } else if ("topicReciver".equalsIgnoreCase(mode)) {
            JMSTopicReciver consumer = new JMSTopicReciver();
            consumer.reciveMessage();
        }
    }
}

打包運行，執行如下命令將客戶端做爲主題發佈者spa