Redis实现消息的发布和订阅

1、在springboot项目的pom.xml

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.4.5</version><relativePath/></parent><groupId>com.example</groupId><artifactId>spring-boot-redis-message</artifactId><version>0.0.1-SNAPSHOT</version><name>spring-boot-redis-message</name><description>spring-boot-redis-message</description><properties><java.version>1.8</java.version></properties><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-redis</artifactId></dependency><dependency><groupId>junit</groupId><artifactId>junit</artifactId><scope>test</scope></dependency></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins></build></project>

2、在application.properties中配置redis参数

# Redis数据库索引（默认为0）
spring.redis.database=0
# Redis服务器地址
spring.redis.host=127.0.0.1
# Redis服务器连接端口
spring.redis.port=6379
# Redis服务器连接密码（默认为空）
spring.redis.password=
# 连接池最大连接数（使用负值表示没有限制）
spring.redis.jedis.pool.max-active=10
# 连接池最大阻塞等待时间（使用负值表示没有限制）
spring.redis.jedis.pool.max-wait=-1ms
# 连接池中的最大空闲连接
spring.redis.jedis.pool.max-idle=10
# 连接池中的最小空闲连接
spring.redis.jedis.pool.min-idle=0
# 连接超时时间（毫秒）
spring.redis.timeout=1000ms

3、redis的配置类

package com.example.springbootredismessage.config;import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
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.RedisTemplate;
import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;import java.net.UnknownHostException;/*** @author zhangshixing* @date 2021年11月06日 9:44* redis 配置类*/
@Configuration
public class RedisConfig {@Bean@ConditionalOnMissingBean(name = "redisTemplate")public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory redisConnectionFactory)throws UnknownHostException {Jackson2JsonRedisSerializer<Object> jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer<Object>(Object.class);ObjectMapper om = new ObjectMapper();om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);jackson2JsonRedisSerializer.setObjectMapper(om);RedisTemplate<String, Object> template = new RedisTemplate<String, Object>();template.setConnectionFactory(redisConnectionFactory);StringRedisSerializer stringSerial = new StringRedisSerializer();// redis key 序列化方式使用stringSerialtemplate.setKeySerializer(stringSerial);// redis value 序列化方式使用jacksontemplate.setValueSerializer(jackson2JsonRedisSerializer);// redis hash key 序列化方式使用stringSerialtemplate.setHashKeySerializer(stringSerial);// redis hash value 序列化方式使用jacksontemplate.setHashValueSerializer(jackson2JsonRedisSerializer);template.afterPropertiesSet();return template;}
}

4、redis消息发布和监听

4.1 发送消息

package com.example.springbootredismessage.controller;import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;import javax.annotation.Resource;/*** @author zhangshixing* @date 2021年11月07日 11:18*/
@RestController
@RequestMapping(value = "rest/redis")
public class RedisSendMessageController {@Resourceprivate RedisTemplate redisTemplate;@RequestMapping(value = "send/message", method = RequestMethod.GET)public void testPush(@RequestParam("body") String body) {/*** 使用redisTemplate的convertAndSend()函数，* String channel, Object message* channel代表管道，* message代表发送的信息*/redisTemplate.convertAndSend("test_topic", body);System.out.println("发送消息成功，channel：test_topic , messgae：" + body);}
}

4.2 接收消息

package com.example.springbootredismessage.config;import org.springframework.data.redis.connection.Message;
import org.springframework.data.redis.connection.MessageListener;
import org.springframework.stereotype.Component;import java.io.UnsupportedEncodingException;/*** @author zhangshixing* @date 2021年11月07日 11:22* redis订阅方:接收消息* 为了接收 Redis 渠道发送过来的消息，我们先定义一个消息监听器（ MessageListener ）*/
@Component
public class MyRedisSubscribeListener implements MessageListener {/*** 这里的 onMessage 方法是得到消息后的处理方法， 其中 message 参数代表 Redis 发送过来的消息，* pattern是渠道名称，onMessage方法里打印了它们的内容。这里因为标注了＠Component注解，所以* 在Spring Boot扫描后，会把它自动装配到IoC容器中 ,监听着对象RedisMessageListener会自动* 将消息进行转换。** @param message* @param bytes*/@Overridepublic void onMessage(Message message, byte[] bytes) {System.out.println("接收消息!");//消息体String body = null;try {//解决string乱码body = new String(message.getBody(), "utf-8");} catch (UnsupportedEncodingException e) {e.printStackTrace();}//渠道名称String topic = new String(bytes);System.out.println("消息体：" + body);System.out.println("渠道名称：" + topic);}
}

5、启动类

package com.example.springbootredismessage;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;@SpringBootApplication
public class SpringBootRedisMessageApplication {public static void main(String[] args) {SpringApplication.run(SpringBootRedisMessageApplication.class, args);}}

6、测试

http://localhost:8080/rest/redis/send/message?body=helloworld