spring boot 使用 ActiveMQ 实现简单的HelloWorld
1. ActiveMQ简介
消息队列使用场景
消息队列在大型电子商务类网站，如京东、淘宝、去哪儿等网站有这深入的应用，队列的主要作用是消除高并发访问高峰，加快网站的响应速度。在不使用消息队列的情况下，用户的请求数据直接写入数据库，在高并发的情况下，会对数据库造成巨大的压力，同时也使得系统响应延迟加剧。在使用队列后，用户的请求发给队列后立即返回（当然不能直接给用户提示订单提交成功，京东上提示：您“您提交了订单，请等待系统确认”），再由消息队列的消费者进程从消息队列中获取数据，异步写入数据库。由于消息队列的服务处理速度远快于数据库，因此用户的响应延迟可得到有效改善。
比如一个电商的后台系统
下载安装ActiveMQ
官网：http://activemq.apache.org/download.html
安装完成后，打开http://127.0.0.1:8161/admin/登录后台管理系统.默认账号密码 admin/admin
后台管理界面如下:
2.创建一个ActiveMQ项目
1.添加依赖
在pom.xml中
<dependency>
<groupId>org.apache.activemq</groupId>
<artifactId>activemq-all</artifactId>
<version>5.14.0</version>
</dependency>
2. 生产者
package ActiveMQ;
import org.apache.activemq.ActiveMQConnection;
import org.apache.activemq.ActiveMQConnectionFactory;
import javax.jms.*;
import java.util.concurrent.atomic.AtomicInteger;
/**
* Created by Administrator on 2017/12/14 0014.
*/
public class Producter {
//ActiveMq 的默认用户名
private static final String USERNAME ="admin";
//ActiveMq 的默认登录密码
private static final String PASSWORD ="admin";
//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<MessageProducer>();
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()+
"productor:我是大帅哥，我现在正在生产东西！,count:"+num);
System.out.println(Thread.currentThread().getName()+
"productor:我是大帅哥，我现在正在生产东西！,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();
}
}
}
3.消费者
package ActiveMQ;
import org.apache.activemq.ActiveMQConnection;
import org.apache.activemq.ActiveMQConnectionFactory;
import javax.jms.*;
import java.util.concurrent.atomic.AtomicInteger;
/**
* Created by Administrator on 2017/12/14 0014.
*/
public class Comsumer {
private static final String USERNAME = "admin";
private static final String PASSWORD = "admin";
private static final String BROKEN_URL = ActiveMQConnection.DEFAULT_BROKER_URL;
ConnectionFactory connectionFactory;
Connection connection;
Session session;
ThreadLocal<MessageConsumer> threadLocal = new ThreadLocal<MessageConsumer>();
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(10);
TextMessage msg = (TextMessage) consumer.receive();
if(msg!=null) {
msg.acknowledge();
System.out.println(Thread.currentThread().getName()+": Consumer:我是消费者，我正在消费Msg"+msg.getText()+"--->"+count.getAndIncrement());
}else {
break;
}
}
} catch (JMSException e) {
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
4.使用多线程测试生产者 （既向ActiveMQ中发送消息）
package ActiveMQ;
/**
* Created by Administrator on 2017/12/14 0014.
*/
public class TestConsumer {
public static void main(String[] args){
Comsumer comsumer = new Comsumer();
comsumer.init();
TestConsumer testConsumer = new TestConsumer();
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{
Comsumer comsumer;
public ConsumerMq(Comsumer comsumer){
this.comsumer = comsumer;
}
@Override
public void run() {
while(true){
try {
comsumer.getMessage("ASLAN1");
Thread.sleep(10000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
}
5.使用多线程测试消费者（既从ActiveMQ中读取消息）
package ActiveMQ;
/**
* Created by Administrator on 2017/12/14 0014.
*/
public class TestConsumer {
public static void main(String[] args){
Comsumer comsumer = new Comsumer();
comsumer.init();
TestConsumer testConsumer = new TestConsumer();
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{
Comsumer comsumer;
public ConsumerMq(Comsumer comsumer){
this.comsumer = comsumer;
}
@Override
public void run() {
while(true){
try {
comsumer.getMessage("ASLAN1");
Thread.sleep(10000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
}
6.测试结果
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