SpringBoot整合Redis实现简单的Pub/Sub（发布/订阅）

Posted 2022-03-04 代码不是马

直接上代码
引入依赖
```html/xml
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>

创建  RedisListener实现MessageListener
```java
package com.test.demotest.service;

import lombok.extern.log4j.Log4j2;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.Message;
import org.springframework.data.redis.connection.MessageListener;

/**
 * @Author: yipeng.liu
 * @Date: 2022/3/2 18:20
 * @Description: RedisListener
 */
@Log4j2
@Configuration
public class RedisListener implements MessageListener 

  @Override
  public void onMessage(Message message, byte[] bytes) 
    //获取订阅消息内容  
    String topic = new String(bytes);
    String context = new String(message.getBody());
    log.info("topic:,context:",topic,context);
  

重写RedisMessageListenerContainer Bean订阅所要监听的topic

package com.test.demotest.service;

import lombok.extern.log4j.Log4j2;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.Message;
import org.springframework.data.redis.connection.MessageListener;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.listener.ChannelTopic;
import org.springframework.data.redis.listener.RedisMessageListenerContainer;

/**
 * @Author: yipeng.liu
 * @Date: 2022/3/2 18:20
 * @Description: RedisListener
 */
@Log4j2
@Configuration
public class RedisListener implements MessageListener 

  @Override
  public void onMessage(Message message, byte[] bytes) 
    String topic = new String(bytes);
    String context = new String(message.getBody());
    log.info("topic:,context:",topic,context);
  

  @Bean
  RedisMessageListenerContainer redisMessageListenerContainer(
      RedisConnectionFactory redisConnectionFactory,RedisListener redisListener) 
    RedisMessageListenerContainer redisMessageListenerContainer = new RedisMessageListenerContainer();
    redisMessageListenerContainer.setConnectionFactory(redisConnectionFactory);
    //订阅topic - subscribe
    redisMessageListenerContainer.addMessageListener(redisListener,new ChannelTopic("subscribe"));
    return redisMessageListenerContainer;
  

编写测试类

package com.test.demotest.contoller;

import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.data.redis.core.StringRedisTemplate;

/** @Author: yipeng.liu @Date: 2022/3/2 18:43 @Description: RedisTest */
@SpringBootTest
public class RedisTest 

  @Autowired private StringRedisTemplate stringRedisTemplate;

  @Test
  void redisTest() throws InterruptedException 
    int i = 0;
    while (i < 10) 
      i++;
      stringRedisTemplate.convertAndSend("subscribe", "发布信息" + i);
      Thread.sleep(3000);
    
  

运行结果有如下：

这里要说一下
为什么使用StringRedisTemplate而不使用RedisTemplate
RedisTemplate是使用JdkSerializationRedisSerializer进行序列化
StringRedisTemplate是使用StringRedisSerializer进行序列化
RedisTemplate会将数据序列化为字节数组储存到Redis中
StringRedisTemplate会将数据序列化为可读数组储存下来
注意：只要当你要存的数据是字符串时才是用StringRedisTemplate