SpringBoot Redis消息发布与订阅

时间:2022-05-28 逆着黑夜便是光人气:0

1.什么是redis的发布与订阅

在官网的文档介绍中有一行介绍：Redis是一个快速稳定的发布/订阅消息系统。

2.Redis发布订阅

机制

Redis提供了发布与订阅的功能，可以用于消息的传输，Redis的发布订阅机制包括三部分，发布者、订阅者和Channel（主题或者队列）。

3.命令行实现功能

订阅主题

Redis采用SUBSCRIBE channel命令订阅某个主题，返回的参数subscribe表示已经成功订阅主题，第二个参数表示订阅的主题名称，第三个表示当前订阅数

127.0.0.1:6379> SUBSCRIBE ORDER-PAY-SUCCESS
Reading messages... (press Ctrl-C to quit)
1) "subscribe"
2) "ORDER-PAY-SUCCESS"
3) (integer) 1

模式匹配订阅

模式匹配功能是允许客户端订阅匹配某种模式的频道，Redis采用PSUBSCRIBE channel命令订阅匹配某种模式的所有频道，用*表示模式，*可以被任意值代替。

127.0.0.1:6379> PSUBSCRIBE ORDER-PAY-*
Reading messages... (press Ctrl-C to quit)
1) "psubscribe"
2) "ORDER-PAY-*"
3) (integer) 1

发布消息

Redis采用PUBLISH channel message命令在某个主题上发布消息，返回的参数是接收到消息的订阅者个数

127.0.0.1:6379> PUBLISH ORDER-PAY-SUCCESS DD202109071525
(integer) 1

取消订阅

Redis采用UNSUBSCRIBE channel或PUNSUBSCRIBE channel命令取消某个主题的订阅，由于Redis的订阅操作是阻塞式的，因此一旦客户端订阅了某个频道或模式，就将会一直处于订阅状态直到退出。在 SUBSCRIBE，PSUBSCRIBE，UNSUBSCRIBE 和 PUNSUBSCRIBE 命令中，其返回值都包含了该客户端当前订阅的频道和模式的数量，当这个数量变为0时，该客户端会自动退出订阅状态。

127.0.0.1:6379> UNSUBSCRIBE ORDER-PAY-SUCCESS
1) "unsubscribe"
2) "ORDER-PAY-SUCCESS"
3) (integer) 0
127.0.0.1:6379> PUNSUBSCRIBE ORDER-PAY-SUCCESS
1) "punsubscribe"
2) "ORDER-PAY-SUCCESS"
3) (integer) 0

测试

首先三个订阅者订阅ORDER-PAY-SUCCESS主题，当发送者在这个主题内发送订单号时，所有的订阅者都会收到这个主题的消息。

4.SpringBoot实现功能

Springboot整合Redis

引入依赖包

<dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
            <version>2.2.10.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <version>2.2.10.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
            <version>2.4.1</version>
        </dependency>
    </dependencies>

配置yaml文件

server:
  port: 8888

spring:
  application:
    name: spring-boot-redis
  redis:
    host: 127.0.0.1
    port: 6379

配置消息监听

import com.demo.redis.listener.MessageListener;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.listener.PatternTopic;
import org.springframework.data.redis.listener.RedisMessageListenerContainer;
import org.springframework.data.redis.listener.adapter.MessageListenerAdapter;

/**
 * @author Bai
 * @date 2021/4/29 上午 11:17
 * @description
 */
@Configuration
public class RedisMessageConfig {

    /**
     * 监听订单支付完成主题
     */
    private static final String ORDER_PAY_SUCCESS = "ORDER-PAY-SUCCESS";

    /**
     * 注入消息监听适配器
     * @param messageListener
     * @return {@link MessageListenerAdapter}
     * @throws
     * @author Bai
     * @date 2021/9/7 下午 03:54
     */
    @Bean
    public MessageListenerAdapter getMessageListenerAdapter(MessageListener messageListener){
        return new MessageListenerAdapter(messageListener, "onMessage");
    }

    /**
     * 注入消息监听容器
     * @param redisConnectionFactory
     * @param messageListenerAdapter
     * @return {@link RedisMessageListenerContainer}
     * @throws
     * @author Bai
     * @date 2021/9/7 下午 03:54
     */
    @Bean
    public RedisMessageListenerContainer getRedisMessageListenerContainer(RedisConnectionFactory redisConnectionFactory, MessageListenerAdapter messageListenerAdapter){
        RedisMessageListenerContainer redisMessageListenerContainer = new RedisMessageListenerContainer();
        redisMessageListenerContainer.setConnectionFactory(redisConnectionFactory);

        //订阅订单支付成功主题
        redisMessageListenerContainer.addMessageListener(messageListenerAdapter, new PatternTopic(ORDER_PAY_SUCCESS));
        return redisMessageListenerContainer;
    }

    /**
     * 处理内容
     * @param connectionFactory
     * @return {@link StringRedisTemplate}
     * @throws
     * @author Bai
     * @date 2021/9/7 下午 04:01
     */
    @Bean
    StringRedisTemplate template(RedisConnectionFactory connectionFactory) {
        return new StringRedisTemplate(connectionFactory);
    }
}

接收消息

import org.springframework.stereotype.Component;

/**
 * @author Bai
 * @date 2021/9/7 下午 03:51
 * @description
 */
@Component
public class MessageListener {

    public void onMessage(String message){
        System.out.println("接收消息：" + message);
    }
}

测试

发送订单支付成功的消息

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.test.context.junit4.SpringRunner;

import javax.annotation.Resource;

/**
 * @author Bai
 * @date 2021/9/7 下午 04:32
 * @description
 */
@RunWith(value = SpringRunner.class)
@SpringBootTest
public class RedisPubTest {

    /**
     * 订单支付完成主题
     */
    private static final String ORDER_PAY_SUCCESS = "ORDER-PAY-SUCCESS";

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    /**
     * 模拟发送5调订单支付完成的消息
     * @throws
     * @author Bai
     * @date 2021/9/7 下午 04:57
     */
    @Test
    public void sendMessage(){
        for (int i = 0; i < 5; i++) {
            stringRedisTemplate.convertAndSend(ORDER_PAY_SUCCESS,"DD" + System.currentTimeMillis());
        }
    }
}

接收到订单支付成功的消息

. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v2.2.10.RELEASE)

2021-09-07 16:56:54.729 INFO 3712 --- [ main] com.demo.redis.RedisSubPubApplication : Starting RedisSubPubApplication on DESKTOP-595LI4G with PID 3712 (D:\Bai\Sources\spring-boot-demo\redis-sub-pub\target\classes started by 1 in D:\Bai\Sources\spring-boot-demo)
2021-09-07 16:56:54.735 INFO 3712 --- [ main] com.demo.redis.RedisSubPubApplication : No active profile set, falling back to default profiles: default
2021-09-07 16:56:55.205 INFO 3712 --- [ main] .s.d.r.c.RepositoryConfigurationDelegate : Multiple Spring Data modules found, entering strict repository configuration mode!
2021-09-07 16:56:55.207 INFO 3712 --- [ main] .s.d.r.c.RepositoryConfigurationDelegate : Bootstrapping Spring Data Redis repositories in DEFAULT mode.
2021-09-07 16:56:55.229 INFO 3712 --- [ main] .s.d.r.c.RepositoryConfigurationDelegate : Finished Spring Data repository scanning in 11 ms. Found 0 Redis repository interfaces.
2021-09-07 16:56:55.557 INFO 3712 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8888 (http)
2021-09-07 16:56:55.565 INFO 3712 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2021-09-07 16:56:55.565 INFO 3712 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.38]
2021-09-07 16:56:55.669 INFO 3712 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2021-09-07 16:56:55.669 INFO 3712 --- [ main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 895 ms
2021-09-07 16:56:56.032 INFO 3712 --- [ main] o.s.s.concurrent.ThreadPoolTaskExecutor : Initializing ExecutorService 'applicationTaskExecutor'
2021-09-07 16:56:56.950 INFO 3712 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8888 (http) with context path ''
2021-09-07 16:56:56.952 INFO 3712 --- [ main] com.demo.redis.RedisSubPubApplication : Started RedisSubPubApplication in 2.557 seconds (JVM running for 3.436)
接收消息：DD1631005025949
接收消息：DD1631005025964
接收消息：DD1631005025965
接收消息：DD1631005025967
接收消息：DD1631005025968

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