赞
踩
我们将用Java
编写两个程序,发送单个消息的生成者和接收消息并打印出来的消费者。
在下图,“P”
是生成者,“C”
消费者。中间框是一个队列RabbitMQ
保留的消息缓冲区 。
首先构建一个Maven
项目,然后引入依赖。
<!-- 导入rabbitmq原生依赖-->
<dependency>
<groupId>com.rabbitmq</groupId>
<artifactId>amqp-client</artifactId>
<version>5.10.0</version>
</dependency>
import com.duan.rabbitmq.utils.RabbitMqUtil; import com.rabbitmq.client.Channel; import com.rabbitmq.client.Connection; import com.rabbitmq.client.ConnectionFactory; import com.rabbitmq.client.MessageProperties; import java.io.IOException; import java.util.concurrent.TimeoutException; /** * @author db * @version 1.0 * @description Provider 生产者代码 * @since 2022/12/29 */ public class Producer { public static void main(String[] args) throws IOException, TimeoutException { // // 1.创建连接工厂 // ConnectionFactory connectionFactory = new ConnectionFactory(); // // 2.设置连接属性 // connectionFactory.setHost("192.168.137.120"); // connectionFactory.setPort(5672); // connectionFactory.setVirtualHost("/"); // connectionFactory.setUsername("admin"); // connectionFactory.setPassword("123456"); // connectionFactory.setHandshakeTimeout(60000); // // // 3.从连接工厂获得连接 // Connection connection = connectionFactory.newConnection(); // 从工具类中获得连接 Connection connection = RabbitMqUtil.getConnection(); // 4.从连接中获得channel Channel channel = connection.createChannel(); // 5.声明队列queue存储消息 /** * 参数s:队列名称 如果队列不存在就自动创建 * 参数b:用来定义队列特性是否要持久化 true 持久化队列 false 不持久化 * 参数b1: exclusive 是否独占队列 true 独占队列 false 不独占 * 参数b2:autoDelete 是否在消费完成后自动删除队列 true 自动删除 false 不自动删除 * 参数5:额外附加参数 * */ channel.queueDeclare("hello",true,false,false,null); // 7.发送消息给中间件 // 参数1:交换机名称 参数2:队列名称 参数3:传递消息的额外设置 参数4: channel.basicPublish("","hello", MessageProperties.PERSISTENT_TEXT_PLAIN,"hello rabbitmq".getBytes()); System.out.println("消息发送成功"); // // 8.关闭连接 // channel.close(); // connection.close(); RabbitMqUtil.closeConnectionAndChannel(channel,connection); } }
执行发送,这个时候可以在web
控制台查看到这个队列queue
的信息。
import com.duan.rabbitmq.utils.RabbitMqUtil; import com.rabbitmq.client.*; import java.io.IOException; import java.util.concurrent.TimeoutException; /** * @author db * @version 1.0 * @description Consumer 消费者 * @since 2022/12/29 */ public class Consumer { public static void main(String[] args) throws IOException, TimeoutException { // ConnectionFactory connectionFactory = new ConnectionFactory(); // connectionFactory.setHost("192.168.137.120"); // connectionFactory.setPort(5672); // connectionFactory.setVirtualHost("/"); // connectionFactory.setUsername("admin"); // connectionFactory.setPassword("123456"); // connectionFactory.setHandshakeTimeout(60000); // // // 创建连接 // Connection connection = connectionFactory.newConnection(); // 从工具类中获得连接 Connection connection = RabbitMqUtil.getConnection(); // 创建信道 Channel channel = connection.createChannel(); // 消费者成功消费时的回调 DeliverCallback deliverCallback = (consumerTag,message) ->{ System.out.println(new String(message.getBody())); }; // 消费者取消消费时的回调 CancelCallback callback = consumerTag ->{ System.out.println("消费者取消消费接口的回调"); }; // 参数1:消费队列的名称 // 参数2:消息的自动确认机制(已获得消息就通知MQ消息已被消费)true 打开 false 关闭 // 参数3: channel.basicConsume("hello",true,deliverCallback,callback); // channel.close(); // connection.close(); } }
工具类的包装
package com.duan.rabbitmq.utils; import com.rabbitmq.client.Channel; import com.rabbitmq.client.Connection; import com.rabbitmq.client.ConnectionFactory; /** * @author db * @version 1.0 * @description RabbitMqUtil * @since 2023/1/2 */ public class RabbitMqUtil { // 定义提供连接对象的方法 public static Connection getConnection(){ try{ // 1.创建连接工厂 ConnectionFactory connectionFactory = new ConnectionFactory(); // 2.设置连接属性 connectionFactory.setHost("192.168.137.120"); connectionFactory.setPort(5672); connectionFactory.setVirtualHost("/"); connectionFactory.setUsername("admin"); connectionFactory.setPassword("123456"); connectionFactory.setHandshakeTimeout(60000); return connectionFactory.newConnection(); }catch (Exception e){ e.printStackTrace(); } return null; } // 关闭连接通道和关闭连接的工具方法 public static void closeConnectionAndChannel(Channel channel,Connection connection){ try{ if(channel !=null){ channel.close(); } if(connection != null){ connection.close(); } }catch (Exception e){ e.printStackTrace(); } } }
**解决方案:**原因是连接超时,加超时时间。
maevn
项目设置超时时间:factory.setHandshakeTimeout\(60000\)
work queues
被称为任务队列(Task queues)
。当消息处理比较耗时的时候,可能生产消息的速度会远远大于消息的消费速度。长此以往,消息就会堆积越来越多,无法及时处理。此时就可以使用work
模型: 让多个消费者绑定到一个队列,共同消费队列中的消息。 队列中的消息一旦消费,就会消失,因此任务是不会被重复执行的。
package com.duan.rabbitmq.work; import com.duan.rabbitmq.utils.RabbitMqUtil; import com.rabbitmq.client.Channel; import com.rabbitmq.client.Connection; import java.io.IOException; /** * @author db * @version 1.0 * @description Producer * @since 2023/3/24 */ public class Producer { public static void main(String[] args) throws IOException { Connection connection = RabbitMqUtil.getConnection(); Channel channel = connection.createChannel(); /** * 声明队列queue存储信息 * 参数1: 队列名称 * 参数2: 用来定义队列是否要持久化 * 参数3: exclusion 是否是独占队列 * 参数4: autoDelete 是否再消费完成后自动删除队列 * 参数5: 额外附加参数 */ channel.queueDeclare("work",true,false,false,null); for(int i = 0; i<10; i++){ // 参数1:交换机名称 参数2:队列名称 参数3:消息传递的额外设置 channel.basicPublish("","work",null,(i+"work").getBytes()); } RabbitMqUtil.closeConnectionAndChannel(channel,connection); } }
package com.duan.rabbitmq.work; import com.duan.rabbitmq.utils.RabbitMqUtil; import com.rabbitmq.client.*; import java.io.IOException; /** * @author db * @version 1.0 * @description Consumer1 * @since 2023/3/24 */ public class Consumer1 { public static void main(String[] args) throws IOException { Connection connection = RabbitMqUtil.getConnection(); // 创建信道 Channel channel = connection.createChannel(); // 消费者消费成功时的回调 channel.queueDeclare("work",true,false,false,null); channel.basicConsume("work",true,new DefaultConsumer(channel){ @Override public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException{ System.out.println("消费者1: "+new String(body)); } }); RabbitMqUtil.closeConnectionAndChannel(channel,connection); } }
package com.duan.rabbitmq.work; import com.duan.rabbitmq.utils.RabbitMqUtil; import com.rabbitmq.client.*; import java.io.IOException; /** * @author db * @version 1.0 * @description Consumer1 * @since 2023/3/24 */ public class Consumer2 { public static void main(String[] args) throws IOException { Connection connection = RabbitMqUtil.getConnection(); // 创建信道 Channel channel = connection.createChannel(); // 消费者消费成功时的回调 channel.queueDeclare("work",true,false,false,null); channel.basicConsume("work",true,new DefaultConsumer(channel){ @Override public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException{ try{ Thread.sleep(2000); }catch (Exception e){ e.printStackTrace(); } System.out.println("消费者2: "+new String(body)); } }); RabbitMqUtil.closeConnectionAndChannel(channel,connection); } }
rabbitMQ
讲按照顺序将每个消息发给下一个使用者,每个消费者都会收到相同数量的消息。
测试结果
消息确认机制
前面看到的是所有的消费者均分消息,会有一个问题,如果一个消费者宕机了,会出现消息丢失现场,希望当出现消费者宕机时,消息被另一个消费者消费,也就是多劳多得生产者代码。
package com.duan.rabbitmq.work; import com.duan.rabbitmq.utils.RabbitMqUtil; import com.rabbitmq.client.Channel; import com.rabbitmq.client.Connection; import java.io.IOException; /** * @author db * @version 1.0 * @description Producer * @since 2023/3/24 */ public class Producer { public static void main(String[] args) throws IOException { Connection connection = RabbitMqUtil.getConnection(); Channel channel = connection.createChannel(); /** * 声明队列queue存储信息 * 参数1: 队列名称 * 参数2: 用来定义队列是否要持久化 * 参数3: exclusion 是否是独占队列 * 参数4: autoDelete 是否再消费完成后自动删除队列 * 参数5: 额外附加参数 */ channel.queueDeclare("work",true,false,false,null); for(int i = 0; i<20; i++){ // 参数1:交换机名称 参数2:队列名称 参数3:消息传递的额外设置 channel.basicPublish("","work",null,(i+"work").getBytes()); } RabbitMqUtil.closeConnectionAndChannel(channel,connection); } }
生成者1
package com.duan.rabbitmq.work; import com.duan.rabbitmq.utils.RabbitMqUtil; import com.rabbitmq.client.*; import java.io.IOException; /** * @author db * @version 1.0 * @description Consumer3 * @since 2023/11/27 */ public class Consumer3 { public static void main(String[] args) throws IOException { Connection connection = RabbitMqUtil.getConnection(); // 创建信道 Channel channel = connection.createChannel(); channel.basicQos(1); // 每次只消费一个消息 // 消费者消费成功时的回调 channel.queueDeclare("work",true,false,false,null); channel.basicConsume("work",false,new DefaultConsumer(channel){ @Override public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException{ System.out.println("消费者1: "+new String(body)); // 手动确认,参数1:消息标识 参数2:每次确认1个 channel.basicAck(envelope.getDeliveryTag(),false); } }); } }
生成者2
package com.duan.rabbitmq.work; import com.duan.rabbitmq.utils.RabbitMqUtil; import com.rabbitmq.client.*; import java.io.IOException; /** * @author db * @version 1.0 * @description Consumer4 * @since 2023/11/27 */ public class Consumer4 { public static void main(String[] args) throws IOException { Connection connection = RabbitMqUtil.getConnection(); // 创建信道 Channel channel = connection.createChannel(); channel.basicQos(1); // 每次消费一个消息 // 消费者消费成功时的回调 channel.queueDeclare("work",true,false,false,null); channel.basicConsume("work",false,new DefaultConsumer(channel){ @Override public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException{ try{ Thread.sleep(2000); }catch (Exception e){ e.printStackTrace(); } System.out.println("消费者2: "+new String(body)); channel.basicAck(envelope.getDeliveryTag(),false); } }); } }
测试结果
广播模式下:发送消息流程是可以有多个消费者每个消费者都有自己的队列(queue)
每个队列都要绑定交换机(exchange)
生成者发送消息,只能发送到交换机,交换机决定把消息发给哪个队列,生成者无法决定交换机把消息发给绑定过的所有队列,队列的消费者都能拿到消息,一条消息可以被多个消费者消费。
package com.duan.rabbitmq.fanout; import com.duan.rabbitmq.utils.RabbitMqUtil; import com.rabbitmq.client.Channel; import com.rabbitmq.client.Connection; import java.io.IOException; /** * @author db * @version 1.0 * @description Provider * @since 2023/11/28 */ public class Provider { public static void main(String[] args) throws IOException { // 获取连接对象 Connection connection = RabbitMqUtil.getConnection(); Channel channel = connection.createChannel(); // 将通道声明交换机 参数1:交换机名称 参数2:交换机类型 channel.exchangeDeclare("logs","fanout"); // 发送消息 channel.basicPublish("logs","",null,"fanout type message".getBytes()); // 释放资源 RabbitMqUtil.closeConnectionAndChannel(channel,connection); } }
package com.duan.rabbitmq.fanout; import com.duan.rabbitmq.utils.RabbitMqUtil; import com.rabbitmq.client.*; import java.io.IOException; /** * @author db * @version 1.0 * @description Customer1 * @since 2023/11/28 */ public class Customer1 { public static void main(String[] args) throws IOException { // 获得连接对象 Connection connection = RabbitMqUtil.getConnection(); Channel channel = connection.createChannel(); // 通道绑定交换机 channel.exchangeDeclare("logs","fanout"); // 绑定临时队列 String queue = channel.queueDeclare().getQueue(); // 绑定交换机和队列 channel.queueBind(queue,"logs",""); // 消费消息 channel.basicConsume(queue,true,new DefaultConsumer(channel){ @Override public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException { System.out.println("消费者1: "+new String(body)); } }); } }
package com.duan.rabbitmq.fanout; import com.duan.rabbitmq.utils.RabbitMqUtil; import com.rabbitmq.client.*; import java.io.IOException; /** * @author db * @version 1.0 * @description Customer1 * @since 2023/11/28 */ public class Customer2 { public static void main(String[] args) throws IOException { // 获得连接对象 Connection connection = RabbitMqUtil.getConnection(); Channel channel = connection.createChannel(); // 通道绑定交换机 channel.exchangeDeclare("logs","fanout"); // 绑定临时队列 String queue = channel.queueDeclare().getQueue(); // 绑定交换机和队列 channel.queueBind(queue,"logs",""); // 消费消息 channel.basicConsume(queue,true,new DefaultConsumer(channel){ @Override public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException { System.out.println("消费者2: "+new String(body)); } }); } }
package com.duan.rabbitmq.fanout; import com.duan.rabbitmq.utils.RabbitMqUtil; import com.rabbitmq.client.*; import java.io.IOException; /** * @author db * @version 1.0 * @description Customer1 * @since 2023/11/28 */ public class Customer3 { public static void main(String[] args) throws IOException { // 获得连接对象 Connection connection = RabbitMqUtil.getConnection(); Channel channel = connection.createChannel(); // 通道绑定交换机 channel.exchangeDeclare("logs","fanout"); // 绑定临时队列 String queue = channel.queueDeclare().getQueue(); // 绑定交换机和队列 channel.queueBind(queue,"logs",""); // 消费消息 channel.basicConsume(queue,true,new DefaultConsumer(channel){ @Override public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException { System.out.println("消费者3: "+new String(body)); } }); } }
在fanout
模式中,一条消息,会被所有绑定的队列都能消费,但是,在某些场景下,希望不同的消息被不同的队列消费,就需要Direct
类型的exchange
。
在Direc
t模型下:队列与交换机的绑定,不是任意绑定的,而是要指定一个RoutingKey
(路由key
)消息的发送方在向Exchange
发送消息时,也必须指定消息的 RoutingKey
。Exchange
不再把消息交给每一个绑定的队列,而是根据消息的Routing Key
进行判断,只有队列的Routingkey
与消息的 Routing key
完全一致,才会接收到消息。
package com.duan.rabbitmq.direct; import com.duan.rabbitmq.utils.RabbitMqUtil; import com.rabbitmq.client.Channel; import com.rabbitmq.client.Connection; import java.io.IOException; /** * @author db * @version 1.0 * @description Provider * @since 2023/11/28 */ public class Provider { public static void main(String[] args) throws IOException { // 建立连接 Connection connection = RabbitMqUtil.getConnection(); Channel channel = connection.createChannel(); channel.exchangeDeclare("logs_direct","direct"); String routingKey = "error"; channel.basicPublish("logs_direct",routingKey,null,("这是direct模型发布的基于route key: ["+routingKey+"] 发送的消息").getBytes()); RabbitMqUtil.closeConnectionAndChannel(channel,connection); } }
package com.duan.rabbitmq.direct; import com.duan.rabbitmq.utils.RabbitMqUtil; import com.rabbitmq.client.*; import java.io.IOException; /** * @author db * @version 1.0 * @description Consumer1 * @since 2023/11/28 */ public class Consumer1 { public static void main(String[] args) throws IOException { // 获得连接对象 Connection connection = RabbitMqUtil.getConnection(); Channel channel = connection.createChannel(); // 通道绑定交换机 channel.exchangeDeclare("logs_direct","direct"); // 绑定临时队列 String queue = channel.queueDeclare().getQueue(); // 绑定交换机和队列 channel.queueBind(queue,"logs_direct","error"); // 消费消息 channel.basicConsume(queue,true,new DefaultConsumer(channel){ @Override public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException { System.out.println("消费者1: "+new String(body)); } }); } }
package com.duan.rabbitmq.direct; import com.duan.rabbitmq.utils.RabbitMqUtil; import com.rabbitmq.client.*; import java.io.IOException; /** * @author db * @version 1.0 * @description Consumer1 * @since 2023/11/28 */ public class Consumer2 { public static void main(String[] args) throws IOException { // 获得连接对象 Connection connection = RabbitMqUtil.getConnection(); Channel channel = connection.createChannel(); // 通道绑定交换机 channel.exchangeDeclare("logs_direct","direct"); // 绑定临时队列 String queue = channel.queueDeclare().getQueue(); // 绑定交换机和队列 channel.queueBind(queue,"logs_direct","info"); channel.queueBind(queue,"logs_direct","error"); channel.queueBind(queue,"logs_direct","warning"); // 消费消息 channel.basicConsume(queue,true,new DefaultConsumer(channel){ @Override public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException { System.out.println("消费者1: "+new String(body)); } }); } }
当routingKey
为info
时,消费者1和消费者2结果如下:
当routingKey
为error
时,消费者1和消费者2结果如下:
Topic
类型的Exchange
与Direct
相比,都是可以根据RoutingKey
把消息路由到不同的队列。只不过Topic
类型Exchange
可以让队列在绑定BindingKey
的时候使用通配符!BindingKey
一般都是有一个或多个单词组成,多个单词之间以.分割,例如: item.insert
通配符规则:
举例:
item.spu.insert
或者 item.spu
item.spu
package com.duan.rabbitmq.topic; import com.duan.rabbitmq.utils.RabbitMqUtil; import com.rabbitmq.client.Channel; import com.rabbitmq.client.Connection; import java.io.IOException; /** * @author db * @version 1.0 * @description Provider * @since 2023/11/30 */ public class Provider { public static void main(String[] args) throws IOException { //获取连接对象 Connection connection = RabbitMqUtil.getConnection(); Channel channel = connection.createChannel(); //声明交换机以及交换机类型 topic channel.exchangeDeclare("topics","topic"); //发布消息 String routekey = "save.user.delete"; channel.basicPublish("topics",routekey,null,("这里是topic动态路由模型,routekey: ["+routekey+"]").getBytes()); //关闭资源 RabbitMqUtil.closeConnectionAndChannel(channel,connection); } }
package com.duan.rabbitmq.topic; import com.duan.rabbitmq.utils.RabbitMqUtil; import com.rabbitmq.client.*; import java.io.IOException; /** * @author db * @version 1.0 * @description Customer1 * @since 2023/11/30 */ public class Customer1 { public static void main(String[] args) throws IOException { // 获得连接对象 Connection connection = RabbitMqUtil.getConnection(); Channel channel = connection.createChannel(); // 通道绑定交换机 channel.exchangeDeclare("topics","topic"); // 绑定临时队列 String queue = channel.queueDeclare().getQueue(); // 绑定交换机和队列 channel.queueBind(queue,"topics","*.user.*"); // 消费消息 channel.basicConsume(queue,true,new DefaultConsumer(channel){ @Override public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException { System.out.println("消费者1: "+new String(body)); } }); } }
package com.duan.rabbitmq.topic; import com.duan.rabbitmq.utils.RabbitMqUtil; import com.rabbitmq.client.*; import java.io.IOException; /** * @author db * @version 1.0 * @description Customer1 * @since 2023/11/30 */ public class Customer2 { public static void main(String[] args) throws IOException { // 获得连接对象 Connection connection = RabbitMqUtil.getConnection(); Channel channel = connection.createChannel(); // 通道绑定交换机 channel.exchangeDeclare("topics","topic"); // 绑定临时队列 String queue = channel.queueDeclare().getQueue(); // 绑定交换机和队列 channel.queueBind(queue,"topics","*.user.#"); // 消费消息 channel.basicConsume(queue,true,new DefaultConsumer(channel){ @Override public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException { System.out.println("消费者1: "+new String(body)); } }); } }
代码地址:https://gitee.com/duan138/practice-code/tree/dev/rabbitmq-java
以上就是rabbitMQ
中常见的几种模式,这些模型通过交换机(Exchange)
和队列(Queue)
的不同组合与绑定方式实现。本文只是初步了解RabbitMQ
相关知识。后续会讲解怎么在SpringBoot
中应用。
改变你能改变的,接受你不能改变的,关注公众号:程序员康康,一起成长,共同进步。
Copyright © 2003-2013 www.wpsshop.cn 版权所有,并保留所有权利。