場景:用戶註冊,信息寫入數據庫後,須要給用戶發送註冊成功的郵件,再發送註冊成功的郵件。php
1.同步調用:註冊成功後,順序執行發送郵件方法,發送短信方法,最後響應用戶 java
2.並行調用:註冊成功後,用多線程的方式併發執行發郵件和發短信方法,最後響應用戶 git
3.消息隊列:註冊成功後,將要發送的消息用很短的時間寫入消息隊列中,以後響應用戶;發送郵件的服務和發送短息的服務就能夠從消息隊列中異步讀去,而後發送任務。 github
場景:購物下單後,調用庫存系統,更新庫存。web
1.耦合的方式:訂單系統,寫調用庫存系統的邏輯。 spring
2.解耦的方式:訂單系統,將下達的消息寫入消息隊列,庫存系統從消息隊列中讀取消息,更新庫存。 docker
秒殺場景中,咱們能夠設置一個定長的消息隊列,秒殺開始,誰快誰先進入隊列,而後快速返回用戶是否秒到 ,以後在平穩的處理秒殺後的業務。 shell
RabbitMQ是一個由erlang開發的AMQP(Advanved Message Queue Protocol)的開源實現。數據庫
AMQP 中消息的路由過程和 Java 開發者熟悉的 JMS 存在一些差異,AMQP 中增長了 Exchange 和 Binding 的角色。生產者把消息發佈到 Exchange 上,消息最終到達隊列並被 消費者接收,而 Binding 決定交換器的消息應該發送到那個隊列。 apache
Exchange分發消息時根據類型的不一樣分發策略有區別,目前共四種類型:direct、fanout、topic、headers 。headers 匹配 AMQP 消息的 header 而不是路由鍵, headers 交換器和 direct 交換器徹底一致,但性能差不少,目前幾乎用不到了,因此直接看另外三種類型:
咱們使用 docker 來安裝 RabbitMQ。
咱們在 docker hub上選擇官方的帶management管理界面的最新版本。
#獲取rabbitmq鏡像
docker pull rabbitmq:3-management
#啓動 rabbitmq鏡像,5672是mq通訊端口,15672是mq的web管理界面端口
run -d -p 5672:5672 -p 15672:15672 --name myrabbitmq 鏡像ID
複製代碼
訪問127.0.0.1:15672 ,用帳號:guest 密碼:guest 登陸,界面以下:
對rabbitmq的詳細使用在這裏,就不講解了,咱們這節的重點是整合rabbitmq。
建立項目引入rabbitmq依賴。
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.gf</groupId>
<artifactId>springboot-rabbitmq</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>springboot-rabbitmq</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.5.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-amqp</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
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package com.gf.config;
import org.springframework.amqp.support.converter.Jackson2JsonMessageConverter;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.amqp.support.converter.MessageConverter;
/** * 自定義消息轉換器,默認是jdk的序列化轉換器,咱們自定義爲json的 */
@Configuration
public class MyAMQPConfig {
@Bean
public MessageConverter messageConverter() {
return new Jackson2JsonMessageConverter();
}
}
複製代碼
咱們測試建立管理配置、發送消息、接收消息
package com.gf;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.amqp.core.AmqpAdmin;
import org.springframework.amqp.core.Binding;
import org.springframework.amqp.core.DirectExchange;
import org.springframework.amqp.core.FanoutExchange;
import org.springframework.amqp.core.Queue;
import org.springframework.amqp.core.TopicExchange;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
@RunWith(SpringRunner.class)
@SpringBootTest
public class SpringbootRabbitmqApplicationTests {
@Autowired
RabbitTemplate rabbitTemplate;
@Autowired
AmqpAdmin amqpAdmin;
@Test
public void contextLoads() {
}
@Test
public void create(){
//建立Exchange
amqpAdmin.declareExchange( new DirectExchange( "exchange.direct") );
amqpAdmin.declareExchange( new FanoutExchange( "exchange.fanout") );
amqpAdmin.declareExchange( new TopicExchange( "exchange.topic") );
//建立Queue
amqpAdmin.declareQueue( new Queue( "direct.queue" , true ) );
amqpAdmin.declareQueue( new Queue( "fanout.queue" , true ) );
//綁定Queue
amqpAdmin.declareBinding( new Binding( "direct.queue" , Binding.DestinationType.QUEUE , "exchange.direct" , "direct.queue" , null ) );
amqpAdmin.declareBinding( new Binding( "fanout.queue" , Binding.DestinationType.QUEUE , "exchange.direct" , "fanout.queue" , null ) );
amqpAdmin.declareBinding( new Binding( "direct.queue" , Binding.DestinationType.QUEUE , "exchange.fanout" , "" , null ) );
amqpAdmin.declareBinding( new Binding( "fanout.queue" , Binding.DestinationType.QUEUE , "exchange.fanout" , "" , null ) );
amqpAdmin.declareBinding( new Binding( "direct.queue" , Binding.DestinationType.QUEUE , "exchange.topic" , "direct.#" , null ) );
amqpAdmin.declareBinding( new Binding( "fanout.queue" , Binding.DestinationType.QUEUE , "exchange.topic" , "direct.*" , null ) );
}
@Test
public void send2Direct() {
Map<String , Object> map = new HashMap<>();
map.put( "msg" , "這是一條點對點消息" );
map.put( "data" , Arrays.asList("helloworld" , 123 , true) );
rabbitTemplate.convertAndSend( "exchange.direct" , "direct.queue" , map );
}
@Test
public void send2Topic() {
Map<String , Object> map = new HashMap<>();
map.put( "msg" , "這是一條廣播消息" );
map.put( "data" , Arrays.asList("topic消息" , 123 , true) );
rabbitTemplate.convertAndSend( "exchange.fanout" , "", map );
}
@Test
public void receive() {
Object o = rabbitTemplate.receiveAndConvert( "direct.queue" );
o.getClass();
System.out.println(o.getClass());
System.out.println(o);
}
}
複製代碼
監聽消息
package com.gf;
import org.springframework.amqp.rabbit.annotation.EnableRabbit;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
/** * 自動配置 * 1. RabbitAutoConfiguration * 2. 自動配置了鏈接工廠ConnectionFactory * 3. RabbitProperties 封裝了RabbitMQ的配置 * 4. RabbitTemplate : 給RabbitMQ發送和接受消息 * 5. AmqpAdmin : RabbitMQ系統管理功能組件 * 6. @EnableRabbit + @RabbitListener */
@EnableRabbit
@SpringBootApplication
public class SpringbootRabbitmqApplication {
public static void main(String[] args) {
SpringApplication.run(SpringbootRabbitmqApplication.class, args);
}
}
複製代碼
package com.gf.service;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.stereotype.Service;
@Service
public class MQService {
@RabbitListener(queues = "fanout.queue")
public void receive(Message message) {
System.out.println("收到消息 : " + new String(message.getBody()));
}
}
複製代碼