SpringBoot2.4.2下配置Lettuce使用Redis

1. Springboot2.4.2下对Redis的基础集成

1.1 maven添加依赖

    <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
             <version>2.4.2</version>
        </dependency>

注：Springboot2.4.2下默认使用的就是Lettuce而不是Jedis因此无需在依赖进行排除Jedis

1.2 添加Redis配置文件

首先Redis需要准备一个配置文件，本文设定一个单独的文件redis.properties 放在resource文件夹下

redis.properties

  hostName = localhost
  port = 6379
  password = password
  pool.maxIdle = 10000
  pool.minIdle = 1000
  pool.maxWaitMillis = 5000
  pool.maxTotal = 2
  database = 10

1.3 注册RedisTemplate和StringRedisTemplate的Bean

LettuceRedisConfig.java

package com.xxx.demo.redis;

import com.fasterxml.jackson.databind.ObjectMapper;
import org.apache.commons.pool2.impl.GenericObjectPoolConfig;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.data.redis.connection.RedisStandaloneConfiguration;
import org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory;
import org.springframework.data.redis.connection.lettuce.LettucePoolingClientConfiguration;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;

import java.io.Serializable;
import java.time.Duration;

/**
 * @author linkanyway
 * @version 1.0
 * @name LettuceRedisConfig
 * @description TODO
 * @date 2022/01/11 22:44
 */
@Configuration
@PropertySource("classpath:redis.properties")
public class LettuceRedisConfig {

    @Value("${hostName}")
    private String hostName;

    @Value("${password}")
    private String password;
    @Value("${port}")
    private int port;

    @Value("${database}")
    private int database;

    @Value("${pool.maxIdle}")
    private int maxIdle;

    @Value("${pool.minIdle}")
    private int minIdle;

    @Value("${pool.maxWaitMillis}")
    private int maxWaitMillis;

    @Value("${pool.maxTotal}")
    private int maxTotal;


    /**
     * LettuceConnectionFactory
     *
     * @return
     */
    @Bean
    public LettuceConnectionFactory redisConnectionFactory() {
        RedisStandaloneConfiguration redisStandaloneConfiguration = new RedisStandaloneConfiguration ();
        redisStandaloneConfiguration.setHostName (hostName);
        redisStandaloneConfiguration.setPort (port);
        redisStandaloneConfiguration.setPassword (password);
        redisStandaloneConfiguration.setDatabase (database);

        GenericObjectPoolConfig poolConfig = new GenericObjectPoolConfig ();
        poolConfig.setMaxIdle (maxIdle);
        poolConfig.setMinIdle (minIdle);
        poolConfig.setMaxWaitMillis (maxWaitMillis);
        poolConfig.setMaxTotal (maxTotal);

        LettucePoolingClientConfiguration lettucePoolingClientConfiguration =
                LettucePoolingClientConfiguration.builder ().commandTimeout (Duration.ofSeconds (10)).shutdownTimeout (Duration.ZERO).poolConfig (poolConfig).build ();

        LettuceConnectionFactory lettuceConnectionFactory =
                new LettuceConnectionFactory (redisStandaloneConfiguration, lettucePoolingClientConfiguration);
        lettuceConnectionFactory.setShareNativeConnection (false);

        return lettuceConnectionFactory;
    }


    /**
     * RedisTemplate
     *
     * @param connectionFactory
     * @return
     */
    @Bean
    public RedisTemplate<String, Serializable> redisTemplate(LettuceConnectionFactory connectionFactory) {
        RedisTemplate<String, Serializable> redisTemplate = new RedisTemplate<> ();
        redisTemplate.setKeySerializer (new StringRedisSerializer ());
        redisTemplate.setValueSerializer (new GenericJackson2JsonRedisSerializer ());
        redisTemplate.setConnectionFactory (connectionFactory);
        return redisTemplate;
    }


    /**
     * @param factory
     * @return
     */
    @Bean
    public StringRedisTemplate configStringRedisTemplate(@Autowired LettuceConnectionFactory factory) {
        StringRedisTemplate template = new StringRedisTemplate (factory);
        template.setEnableTransactionSupport (true);
        ObjectMapper mapper;
        GenericJackson2JsonRedisSerializer jackson2JsonRedisSerializer = new GenericJackson2JsonRedisSerializer ();
        template.setValueSerializer (new StringRedisSerializer ());
        template.setKeySerializer (new StringRedisSerializer ());
        template.setHashKeySerializer (new StringRedisSerializer ());
        template.setHashValueSerializer (new StringRedisSerializer ());
        template.afterPropertiesSet ();
        return template;
    }

}

1.4 编写一个控制器示例进行redis操作

package com.xx.demo.controller;

import com.xxx.demo.redis.MessagePublisher;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * @author linkanyway
 * @version 1.0
 * @name RedisController
 * @description TODO
 * @date 2022/01/11 22:37
 */
@RestController
@RequestMapping("redis")
public class RedisController {

    final
    StringRedisTemplate redisTemplate;


    public RedisController(StringRedisTemplate redisTemplate) {
        this.redisTemplate = redisTemplate;
   
    }


    @GetMapping("add")
    public String add() {
        redisTemplate.opsForValue ().set ("a", "1");
        return "hi";
    }

}

2. 使用redis进行发布订阅

2.1 添加一个发布者的接口

package com.xxx.demo.redis;

/**
 * @author linkanyway
 * @version 1.0
 * @name MessagePublisher
 * @description TODO
 * @date 2022/01/11 23:45
 */
public interface MessagePublisher {
    void publish(final String message);
}

2.2 添加一个发布者的实现类

RedisMessagePublisher.java

package com.xxx.demo.redis;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.listener.ChannelTopic;

import java.io.Serializable;

/**
 * @author linkanyway
 * @version 1.0
 * @name RedisMessagePublisher
 * @description TODO
 * @date 2022/01/11 23:46
 */
public class RedisMessagePublisher implements MessagePublisher {

    @Autowired
    private RedisTemplate<String, Serializable> redisTemplate;
    @Autowired
    private ChannelTopic topic;

    public RedisMessagePublisher() {
    }

    public RedisMessagePublisher(final RedisTemplate<String, Serializable> redisTemplate, final ChannelTopic topic) {
        this.redisTemplate = redisTemplate;
        this.topic = topic;
    }

    @Override
    public void publish(final String message) {
        redisTemplate.convertAndSend (topic.getTopic (), message);
    }
}

2.3 添加一个消息监听bean

RedisMessageSubscriber.java

package com.xxx.demo.redis;

import org.springframework.data.redis.connection.Message;
import org.springframework.data.redis.connection.MessageListener;
import org.springframework.scheduling.annotation.Async;

/**
 * @author linkanyway
 * @version 1.0
 * @name RedisMessageSubscriber
 * @description TODO
 * @date 2022/01/11 23:47
 */
public class RedisMessageSubscriber implements MessageListener {
    @Override
    @Async
    public void onMessage(Message message, byte[] pattern) {
        System.out.println ("Message received: " + new String (message.getBody ()));
    }
}

2.4 添加bean注册

RedisMessageConfig.java

package com.xxx.demo.redis;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.listener.ChannelTopic;
import org.springframework.data.redis.listener.RedisMessageListenerContainer;
import org.springframework.data.redis.listener.adapter.MessageListenerAdapter;

import java.io.Serializable;

/**
 * @author linkanyway
 * @version 1.0
 * @name RedisMessageConfig
 * @description TODO
 * @date 2022/01/11 23:44
 */
@Configuration
public class RedisMessageConfig {


    @Bean
    MessageListenerAdapter messageListener() {
        return new MessageListenerAdapter (new RedisMessageSubscriber ());
    }

    @Bean
    RedisMessageListenerContainer redisContainer(LettuceConnectionFactory factory) {
        final RedisMessageListenerContainer container = new RedisMessageListenerContainer ();
        container.setConnectionFactory (factory);
        container.addMessageListener (messageListener (), topic ());
        return container;
    }

    @Bean
    MessagePublisher redisPublisher(@Autowired RedisTemplate<String, Serializable> redisTemplate) {
        return new RedisMessagePublisher (redisTemplate, topic ());
    }

    @Bean
    ChannelTopic topic() {
        return new ChannelTopic ("pubsub:queue");
    }
}

2.5 改写之前的控制器如下

package com.xxx.demo.controller;

import com.kreakin.demo.redis.MessagePublisher;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * @author linkanyway
 * @version 1.0
 * @name RedisController
 * @description TODO
 * @date 2022/01/11 22:37
 */
@RestController
@RequestMapping("redis")
public class RedisController {

    final
    StringRedisTemplate redisTemplate;
    final
    MessagePublisher publisher;

    public RedisController(StringRedisTemplate redisTemplate, MessagePublisher publisher) {
        this.redisTemplate = redisTemplate;
        this.publisher = publisher;
    }


    @GetMapping("hi")
    public String hi() {
        redisTemplate.opsForValue ().set ("a", "1");
        return "hi";
    }

    @GetMapping("pub")
    public String pub() {
        publisher.publish ("sdfsf");
        return "ok";
    }
}

3. 监听key的过期事件

RedisKeyExpireSubscriber.java

package com.xxx.demo.redis;

import lombok.extern.slf4j.Slf4j;
import org.springframework.data.redis.connection.Message;
import org.springframework.data.redis.listener.KeyExpirationEventMessageListener;
import org.springframework.data.redis.listener.RedisMessageListenerContainer;
import org.springframework.stereotype.Component;

/**
 * @author linkanyway
 * @version 1.0
 * @name RedisKeyExpireSubscriber
 * @description TODO
 * @date 2022/01/12 00:00
 */
@Slf4j
@Component
public class RedisKeyExpireSubscriber extends KeyExpirationEventMessageListener {
    /**
     * Creates new {@link } for {@code __keyevent@*__:expired} messages.
     *
     * @param listenerContainer must not be {@literal null}.
     */
    public RedisKeyExpireSubscriber(RedisMessageListenerContainer listenerContainer) {
        super (listenerContainer);
    }

    @Override
    public void onMessage(Message message, byte[] pattern) {
        log.error (message.toString ());
    }
}

注意： Redis需要开启事件