Redis实现消息的发布和订阅

Redis实现消息的发布和订阅

1、在springboot项目的pom.xml

<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>4.0.0modelVersion>
    <parent>
        <groupId>org.springframework.bootgroupId>
        <artifactId>spring-boot-starter-parentartifactId>
        <version>2.4.5version>
        <relativePath/>
    parent>

    <groupId>com.examplegroupId>
    <artifactId>spring-boot-redis-messageartifactId>
    <version>0.0.1-SNAPSHOTversion>
    <name>spring-boot-redis-messagename>
    <description>spring-boot-redis-messagedescription>

    <properties>
        <java.version>1.8java.version>
    properties>

    <dependencies>

        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starterartifactId>
        dependency>

        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-testartifactId>
            <scope>testscope>
        dependency>

        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
        dependency>

        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-data-redisartifactId>
        dependency>

        <dependency>
            <groupId>junitgroupId>
            <artifactId>junitartifactId>
            <scope>testscope>
        dependency>

    dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.bootgroupId>
                <artifactId>spring-boot-maven-pluginartifactId>
            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stringSerial
        template.setKeySerializer(stringSerial);
        // redis value 序列化方式使用jackson
        template.setValueSerializer(jackson2JsonRedisSerializer);
        // redis hash key 序列化方式使用stringSerial
        template.setHashKeySerializer(stringSerial);
        // redis hash value 序列化方式使用jackson
        template.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 {

    @Resource
    private 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
     */
    @Override
    public 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