spring boot 自学笔记(五) Rabbitmq集成,延时消息队列实现

本篇主要记录Spring boot 集成Rabbitmq，分为两部分， 第一部分为创建普通消息队列， 第二部分为延时消息队列实现：

spring boot提供对mq消息队列支持amqp相关包，引入即可：

<!-- rabbit mq -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-amqp</artifactId>
</dependency>

属性配置文件application.properties:

#rabbitmq
spring.rabbitmq.host=127.0.0.1
spring.rabbitmq.port=5672
spring.rabbitmq.username=root
spring.rabbitmq.password=root

RabbitMq配置类,配置连接工厂以及操作对象:

@Configuration
@ConfigurationProperties(prefix = "spring.rabbitmq")
public class RabbitMQConfiguration {

private static Logger logger = Logger.getLogger(RabbitMQConfiguration.class);

private String host;

private int port;

private String username;

private String password;

// 链接信息
@Bean
public ConnectionFactory connectionFactory() {
CachingConnectionFactory connectionFactory = new CachingConnectionFactory(host, port);
connectionFactory.setUsername(username);
connectionFactory.setPassword(password);
connectionFactory.setVirtualHost("/");
connectionFactory.setPublisherConfirms(true);
logger.info("Create ConnectionFactory bean ..");
return connectionFactory;
}

@Bean
@Scope(ConfigurableBeanFactory.SCOPE_PROTOTYPE)
public RabbitTemplate rabbitTemplate() {
RabbitTemplate template = new RabbitTemplate(connectionFactory());
return template;
}
//省略getter setter

}

定义Service接口如下：

暂时不考虑延时队列，定义发送消息接口

/**
*
* @author victor
* @desc 消息队列服务接口
*/
public interface IMessageQueueService {

/**
* 发送消息到队列
* @param queue 队列名称
* @param message 消息内容
*/
public void send(String queueName,String message);

}

Service实现

package com.ks.server.service.impl.queue;

import org.springframework.amqp.AmqpException;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.core.MessagePostProcessor;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.base.common.codec.JSONUtils;
import com.ks.common.constant.MQConstant;
import com.ks.common.service.queue.IMessageQueueService;
import com.ks.modal.queue.DLXMessage;

/**
*
* @author victor
* @desc 消息队列服务接口实现
*/
@Service("messageQueueService")
public class MessageQueueServiceImpl implements IMessageQueueService{

@Autowired
private RabbitTemplate rabbitTemplate;

@Override
public void send(String queueName, String msg) {
rabbitTemplate.convertAndSend(MQConstant.DEFAULT_EXCHANGE,queueName, msg);
}
}

相关常量类:

package com.ks.common.constant;

/**
*
* @author victor
* @desc Rabbit消息队列相关常量
*/
public final class MQConstant {

private MQConstant(){
}
//exchange name
public static final String DEFAULT_EXCHANGE = "KSHOP";

//DLX QUEUE
public static final String DEFAULT_DEAD_LETTER_QUEUE_NAME = "kshop.dead.letter.queue";

//DLX repeat QUEUE 死信转发队列
public static final String DEFAULT_REPEAT_TRADE_QUEUE_NAME = "kshop.repeat.trade.queue";

//Hello 测试消息队列名称
public static final String HELLO_QUEUE_NAME = "HELLO";

}

到现在为止,队列相关配置，以及使用以及封装完成，接下来是创建队列，

这里我是单独创建一个配置类，用于队列配置， 创建Hello队列示例如下:

package com.ks.ons.config;

import java.util.HashMap;
import java.util.Map;

import org.springframework.amqp.core.Binding;
import org.springframework.amqp.core.BindingBuilder;
import org.springframework.amqp.core.DirectExchange;
import org.springframework.amqp.core.Queue;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import com.ks.common.constant.MQConstant;

/**
*
* @author victor
* @desc 队列配置
*/
@Configuration
public class QueueConfiguration {

//信道配置
@Bean
public DirectExchange defaultExchange() {
return new DirectExchange(MQConstant.DEFAULT_EXCHANGE, true, false);
}
/*********************    hello 队列  测试    *****************/
@Bean
public Queue queue() {
Queue queue = new Queue(MQConstant.HELLO_QUEUE_NAME,true);
return queue;
}
@Bean
public Binding binding() {
return BindingBuilder.bind(queue()).to(defaultExchange()).with(MQConstant.HELLO_QUEUE_NAME);
}
}

通过配置队列bean，在程序启动时会在rabbitmq中创建相关队列，启动程序，可以在rabbtmq管理界面看到信道和队列信息:





众所周知，既然有了队列，用来处理业务的最终还是需要消费者，消费者创建示例如下:

package com.ks.ons.processor.hello;

import org.springframework.amqp.rabbit.annotation.RabbitHandler;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.stereotype.Component;

import com.ks.common.constant.MQConstant;

/**
*
* @author victor
* @desc hello 消息队列消费者
*/
@Component
@RabbitListener(queues = MQConstant.HELLO_QUEUE_NAME)
public class HelloProcessor {

@RabbitHandler
public void process(String content) {
System.out.println("接受消息:" + content);
}}

注入service

@Autowired
private IMessageQueueService messageQueueService;

发送消息

messageQueueService.send(MQConstant.HELLO_QUEUE_NAME, "测试发送消息");

接下来展示如何实现延时队列，在此之前如果读者像我一样对rabbitmq队列了解程度并不深入的话，--> 推荐文章， 可以对rabbitmq延时队列实现思路有大概了解. 
在本文中，主要是通过rabbitmq的DLX特性来实现发送延时队列：

思路如下：



客户端：指具体往MQ发生消息端， 客户端将消息内容进行自定义包装， 将消息中附带目标队列名称。如：客户端向队列Q1发送字符串“hello” , 延时时间为60秒， 包装后修改为{"queueName":"Q1","body": “hello”}，此时，将消息发送到DLX死信队列，而非Q1队列，并将消息设置为60秒超时。

DLX：死信队列，用来存储有超时时间信息的消息， 并且可以设置当消息超时时，转发到另一个指定队列(此处设置转发到router), 无消费者，当接收到客户端消息之后，等待消息超时，将消息转发到指定的Router队列

Router: 转发队列，用来接收死信队列超时消息， 如上示例消息，在接收到之后，消费者将消息解析，获取queueName，body,再向所获取的queueName队列发送一条消息，内容为body.

Q1,Q2,Q3.： 用户业务队列，当Q1收到hello，已经是60秒之后，再进行消费

修改上面代码 ， 新增两个队列，

死信队列：存放发送的延时消息，  

路由转发队列：用于接受死信消息死亡， 并将消息转发到业务目标队列

修改之后代码如下：

/**
*
* @author victor
* @desc 队列配置
*/
@Configuration
public class QueueConfiguration {

//信道配置
@Bean
public DirectExchange defaultExchange() {
return new DirectExchange(MQConstant.DEFAULT_EXCHANGE, true, false);
}
@Bean
public Queue repeatTradeQueue() {
Queue queue = new Queue(MQConstant.DEFAULT_REPEAT_TRADE_QUEUE_NAME,true,false,false);
return queue;
}
@Bean
public Binding  drepeatTradeBinding() {
return BindingBuilder.bind(repeatTradeQueue()).to(defaultExchange()).with(MQConstant.DEFAULT_REPEAT_TRADE_QUEUE_NAME);
}
@Bean
public Queue deadLetterQueue() {
Map<String, Object> arguments = new HashMap<>();
arguments.put("x-dead-letter-exchange", MQConstant.DEFAULT_EXCHANGE);
arguments.put("x-dead-letter-routing-key", MQConstant.DEFAULT_REPEAT_TRADE_QUEUE_NAME);
Queue queue = new Queue(MQConstant.DEFAULT_DEAD_LETTER_QUEUE_NAME,true,false,false,arguments);
System.out.println("arguments :" + queue.getArguments());
return queue;
}
@Bean
public Binding  deadLetterBinding() {
return BindingBuilder.bind(deadLetterQueue()).to(defaultExchange()).with(MQConstant.DEFAULT_DEAD_LETTER_QUEUE_NAME);
}
/*********************    hello 队列  测试    *****************/
@Bean
public Queue queue() {
Queue queue = new Queue(MQConstant.HELLO_QUEUE_NAME,true);
return queue;
}
@Bean
public Binding binding() {
return BindingBuilder.bind(queue()).to(defaultExchange()).with(MQConstant.HELLO_QUEUE_NAME);
}
}

修改Service服务：

package com.ks.common.service.queue;

/**
*
* @author victor
* @desc 消息队列服务接口
*/
public interface IMessageQueueService {

/**
* 发送消息到队列
* @param queue 队列名称
* @param message 消息内容
*/
public void send(String queueName,String message);

/**
* 延迟发送消息到队列
* @param queue 队列名称
* @param message 消息内容
* @param times 延迟时间 单位毫秒
*/
public void send(String queueName,String message,long times);
}

package com.ks.server.service.impl.queue;

import org.springframework.amqp.AmqpException;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.core.MessagePostProcessor;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.base.common.codec.JSONUtils;
import com.ks.common.constant.MQConstant;
import com.ks.common.service.queue.IMessageQueueService;
import com.ks.modal.queue.DLXMessage;

/**
*
* @author victor
* @desc 消息队列服务接口实现
*/
@Service("messageQueueService")
public class MessageQueueServiceImpl implements IMessageQueueService{

@Autowired
private RabbitTemplate rabbitTemplate;

@Override
public void send(String queueName, String msg) {
rabbitTemplate.convertAndSend(MQConstant.DEFAULT_EXCHANGE,queueName, msg);
}
@Override
public void send(String queueName, String msg, long times) {
DLXMessage dlxMessage = new DLXMessage(queueName,msg,times);
MessagePostProcessor processor = new MessagePostProcessor(){
@Override
public Message postProcessMessage(Message message) throws AmqpException {
message.getMessageProperties().setExpiration(times + "");
return message;
}};
dlxMessage.setExchange(MQConstant.DEFAULT_EXCHANGE);
rabbitTemplate.convertAndSend(MQConstant.DEFAULT_EXCHANGE,MQConstant.DEFAULT_DEAD_LETTER_QUEUE_NAME, JSONUtils.toJson(dlxMessage), processor);
}
}

JSONUtils 为一个JSON工具类

新增消息实体，用于包装消息：

package com.ks.modal.queue;

import java.io.Serializable;

/**
*
* @author victor
* @desc rabbit 死信消息载体
*/
public class DLXMessage implements Serializable {

private static final long serialVersionUID = 9956432152000L;

public DLXMessage() {
super();
}
public DLXMessage(String queueName, String content, long times) {
super();
this.queueName = queueName;
this.content = content;
this.times = times;
}
public DLXMessage(String exchange, String queueName, String content, long times) {
super();
this.exchange = exchange;
this.queueName = queueName;
this.content = content;
this.times = times;
}
private String exchange;

private String queueName;

private String content;

private long times;

//省略getter setter

}

路由转发队列消费者实现，负责接收超时消息，进行转发：

package com.ks.ons.processor.system;

import org.springframework.amqp.rabbit.annotation.RabbitHandler;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import com.base.common.codec.JSONUtils;
import com.ks.common.constant.MQConstant;
import com.ks.common.service.queue.IMessageQueueService;
import com.ks.modal.queue.DLXMessage;

/**
*
* @author victor
* @desc 死信接收处理消费者
*/
@Component
@RabbitListener(queues = MQConstant.DEFAULT_REPEAT_TRADE_QUEUE_NAME)
public class TradeProcessor {

@Autowired
private IMessageQueueService messageQueueService;

@RabbitHandler
public void process(String content) {
DLXMessage message = JSONUtils.toBean(content, DLXMessage.class);
messageQueueService.send(message.getQueueName(), message.getContent());
}}

启动项目之后，管理界面如下:



测试代码片段：

messageQueueService.send(MQConstant.HELLO_QUEUE_NAME,"测试延迟发送消息",60000);