初探active mq

mq（message queue），即消息队列，目前比较流行消息队列是active mq 和kafka。本文介绍如何简单的使用active mq。

ActiveMQ官网下载地址：http://activemq.apache.org/download.html

ActiveMQ 提供了Windows 和Linux、Unix 等几个版本，可简单使用windows版本。下载解压启动即可，进入apache-activemq-5.15.8\bin\win64目录，双击activemq.bat即可启动。

从它的目录来说，还是很简单的：

• bin存放的是脚本文件
• conf存放的是基本配置文件
• data存放的是日志文件
• docs存放的是说明文档
• examples存放的是简单的实例
• lib存放的是activemq所需jar包
• webapps用于存放项目的目录

ActiveMQ默认启动时，启动了内置的jetty服务器，提供一个用于监控ActiveMQ的admin应用。 
　　admin：http://127.0.0.1:8161/admin/

　　我们在浏览器打开链接之后输入账号密码（这里和tomcat 服务器类似）

　　默认账号：admin

　　密码：admin

到这里为止，ActiveMQ 服务端就启动完毕了。

接下来是代码：

pom.xml添加如下：

<!-- https://mvnrepository.com/artifact/org.apache.activemq/activemq-all -->
    <dependency>
        <groupId>org.apache.activemq</groupId>
        <artifactId>activemq-all</artifactId>
        <version>5.15.8</version>
    </dependency>

创建4个类，分别是两个工具类和两个测试类；

消息队列分为生成者（producter）和消费者（consumer）

1、创建生产者工具类

package com.wzl.demo.utils;

import java.util.concurrent.atomic.AtomicInteger;

import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.JMSException;
import javax.jms.MessageProducer;
import javax.jms.Queue;
import javax.jms.Session;
import javax.jms.TextMessage;

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

public class ActiveMQProducter {

    //ActiveMq 的默认用户名
    private static final String USERNAME = ActiveMQConnection.DEFAULT_USER;
    //ActiveMq 的默认登录密码
    private static final String PASSWORD = ActiveMQConnection.DEFAULT_PASSWORD;
    //ActiveMQ 的链接地址
    private static final String BROKEN_URL = ActiveMQConnection.DEFAULT_BROKER_URL;

    AtomicInteger count = new AtomicInteger(0);
    //链接工厂
    ConnectionFactory connectionFactory;
    //链接对象
    Connection connection;
    //事务管理
    Session session;
    ThreadLocal<MessageProducer> threadLocal = new ThreadLocal<>();

    public void init(){
        try {
            //创建一个链接工厂
            connectionFactory = new ActiveMQConnectionFactory(USERNAME,PASSWORD,BROKEN_URL);
            //从工厂中创建一个链接
            connection  = connectionFactory.createConnection();
            //开启链接
            connection.start();
            //创建一个事务（这里通过参数可以设置事务的级别）
            session = connection.createSession(true,Session.SESSION_TRANSACTED);
        } catch (JMSException e) {
            e.printStackTrace();
        }
    }

    public void sendMessage(String disname){
        try {
            //创建一个消息队列
            Queue queue = session.createQueue(disname);
            //消息生产者
            MessageProducer messageProducer = null;
            if(threadLocal.get()!=null){
                messageProducer = threadLocal.get();
            }else{
                messageProducer = session.createProducer(queue);
                threadLocal.set(messageProducer);
            }
            while(true){
                Thread.sleep(1000);
                int num = count.getAndIncrement();
                //创建一条消息
                TextMessage msg = session.createTextMessage(Thread.currentThread().getName()+
                        "producter:生产了一条消息！,count:"+num);
                System.out.println(Thread.currentThread().getName()+
                        "producter:生产了一条消息！,count:"+num);
                //发送消息
                messageProducer.send(msg);
                //提交事务
                session.commit();
            }
        } catch (JMSException e) {
            e.printStackTrace();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}

2、创建消费者工具类

package com.wzl.demo.utils;

import java.util.concurrent.atomic.AtomicInteger;

import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.JMSException;
import javax.jms.MessageConsumer;
import javax.jms.Queue;
import javax.jms.Session;
import javax.jms.TextMessage;

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

public class ActiveMQConsumer {

    private static final String USERNAME = ActiveMQConnection.DEFAULT_USER;

    private static final String PASSWORD = ActiveMQConnection.DEFAULT_PASSWORD;

    private static final String BROKEN_URL = ActiveMQConnection.DEFAULT_BROKER_URL;

    ConnectionFactory connectionFactory;

    Connection connection;

    Session session;

    ThreadLocal<MessageConsumer> threadLocal = new ThreadLocal<>();
    AtomicInteger count = new AtomicInteger();

    public void init(){
        try {
            connectionFactory = new ActiveMQConnectionFactory(USERNAME,PASSWORD,BROKEN_URL);
            connection  = connectionFactory.createConnection();
            connection.start();
            session = connection.createSession(false,Session.AUTO_ACKNOWLEDGE);
        } catch (JMSException e) {
            e.printStackTrace();
        }
    }

    public void getMessage(String disname){
        try {
            Queue queue = session.createQueue(disname);
            MessageConsumer consumer = null;

            if(threadLocal.get()!=null){
                consumer = threadLocal.get();
            }else{
                consumer = session.createConsumer(queue);
                threadLocal.set(consumer);
            }
            while(true){
                Thread.sleep(1000);
                TextMessage msg = (TextMessage) consumer.receive();
                if(msg!=null) {
                    msg.acknowledge();
                    System.out.println(Thread.currentThread().getName()+": Consumer:消费了一条消息："+msg.getText()+"-->"+count.getAndIncrement());
                }else {
                    break;
                }
            }
        } catch (JMSException e) {
            e.printStackTrace();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}

3、创建生产者测试类

package com.wzl.demo.action;

import com.wzl.demo.utils.ActiveMQProducter;

public class TestMQProducter {
    public static void main(String[] args){
        ActiveMQProducter producter = new ActiveMQProducter();
        producter.init();
        TestMQProducter testMq = new TestMQProducter();
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        //Thread 1
        new Thread(testMq.new ProductorMq(producter)).start();
        //Thread 2
        new Thread(testMq.new ProductorMq(producter)).start();
        //Thread 3
        new Thread(testMq.new ProductorMq(producter)).start();
        //Thread 4
        new Thread(testMq.new ProductorMq(producter)).start();
        //Thread 5
        new Thread(testMq.new ProductorMq(producter)).start();
    }

    private class ProductorMq implements Runnable{
        ActiveMQProducter producter;
        public ProductorMq(ActiveMQProducter producter){
            this.producter = producter;
        }

        @Override
        public void run() {
            while(true){
                try {
                    producter.sendMessage("Jaycekon-MQ");
                    Thread.sleep(10000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

4、创建消费者测试类

package com.wzl.demo.action;

import com.wzl.demo.utils.ActiveMQConsumer;

public class TestMQConsumer {
    public static void main(String[] args){
        ActiveMQConsumer comsumer = new ActiveMQConsumer();
        comsumer.init();
        TestMQConsumer testConsumer = new TestMQConsumer();
        new Thread(testConsumer.new ConsumerMq(comsumer)).start();
        new Thread(testConsumer.new ConsumerMq(comsumer)).start();
        new Thread(testConsumer.new ConsumerMq(comsumer)).start();
        new Thread(testConsumer.new ConsumerMq(comsumer)).start();
    }

    private class ConsumerMq implements Runnable{
        ActiveMQConsumer comsumer;
        public ConsumerMq(ActiveMQConsumer comsumer){
            this.comsumer = comsumer;
        }

        @Override
        public void run() {
            while(true){
                try {
                    comsumer.getMessage("Jaycekon-MQ");
                    Thread.sleep(10000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

运行生成者测试类和消费测试类，可以观看服务端可视化界面的数量变化。