SpringBoot整合MP通过Redis实现二级缓存方式

spring:
  redis:
    host: 127.0.0.1
    port: 6379
    database: 0
  #配置redis
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    type: com.alibaba.druid.pool.DruidDataSource
    username: root
    password: root
    url: jdbc:mysql://localhost:3306/db?useUnicode=true&characterEncoding=UTF-8
#配置Mybatis-Plus
mybatis-plus:
  mapper-locations: classpath:mybatis/mapper/*.xml
  configuration:
    cache-enabled: true

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;
 
@Configuration
public class RedisConfiguration {
 
    /**
    * 设置redisTemplate
    */
    @Bean(name = "redisTemplate")
    public RedisTemplate<Object, Object> redisTemplate(LettuceConnectionFactory redisConnectionFactory) {
        RedisTemplate<Object, Object> redisTemplate = new RedisTemplate<>();
        redisTemplate.setConnectionFactory(redisConnectionFactory);
        redisTemplate.afterPropertiesSet();
        return redisTemplate;
    }
}

import lombok.extern.slf4j.Slf4j;
import org.apache.ibatis.cache.Cache;
import org.springframework.data.redis.connection.RedisServerCommands;
import org.springframework.data.redis.core.RedisCallback;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.util.CollectionUtils;
 
import javax.annotation.Resource;
import java.util.Set;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
 
/**
 *
 * 使用redis实现Mybatis Plus二级缓存
 *
 */
@Slf4j
public class MybatisRedisCache implements Cache {
 
 
    // 读写锁
    private final ReadWriteLock readWriteLock = new ReentrantReadWriteLock(true);
 
    private RedisTemplate redisTemplate;
 
    private RedisTemplate getRedisTemplate(){
        //通过ApplicationContextHolder工具类获取RedisTemplate
        if (redisTemplate == null) {
            redisTemplate = (RedisTemplate) ApplicationContextHolder.getBeanByName("redisTemplate");
        }
        return redisTemplate;
    }
 
    private final String id;
 
    public MybatisRedisCache(String id) {
        if (id == null) {
            throw new IllegalArgumentException("Cache instances require an ID");
        }
        this.id = id;
    }
 
    @Override
    public String getId() {
        return this.id;
    }
 
    @Override
    public void putObject(Object key, Object value) {
        //使用redis的Hash类型进行存储
        getRedisTemplate().opsForHash().put(id,key.toString(),value);
    }
 
    @Override
    public Object getObject(Object key) {
        try {
            //根据key从redis中获取数据
            return getRedisTemplate().opsForHash().get(id,key.toString());
        } catch (Exception e) {
            e.printStackTrace();
            log.error("缓存出错 ");
        }
        return null;
    }
 
    @Override
    public Object removeObject(Object key) {
        if (key != null) {
            getRedisTemplate().delete(key.toString());
        }
        return null;
    }
 
    @Override
    public void clear() {
        log.debug("清空缓存");
        Set<String> keys = getRedisTemplate().keys("*:" + this.id + "*");
        if (!CollectionUtils.isEmpty(keys)) {
            getRedisTemplate().delete(keys);
        }
    }
 
    @Override
    public int getSize() {
        Long size = (Long) getRedisTemplate().execute((RedisCallback<Long>) RedisServerCommands::dbSize);
        return size.intValue();
    }
 
    @Override
    public ReadWriteLock getReadWriteLock() {
        return this.readWriteLock;
    }
}

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;
 
@Component
public class ApplicationContextHolder implements ApplicationContextAware {
    private static ApplicationContext applicationContext;
 
    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        ApplicationContextHolder.applicationContext = applicationContext;
    }
 
    //根据bean name 获取实例
    public static Object getBeanByName(String beanName) {
        if (beanName == null || applicationContext == null) {
            return null;
        }
        return applicationContext.getBean(beanName);
    }
    //只适合一个class只被定义一次的bean（也就是说，根据class不能匹配出多个该class的实例）
    public static Object getBeanByType(Class clazz) {
        if (clazz == null || applicationContext == null) {
            return null;
        }
        return applicationContext.getBean(clazz);
    }
    public static String[] getBeanDefinitionNames() {
        return applicationContext.getBeanDefinitionNames();
    }
}

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.chenyx.config.MybatisRedisCache;
import com.chenyx.entity.WeChatUser;
import org.apache.ibatis.annotations.CacheNamespace;
 
 
@CacheNamespace(implementation= MybatisRedisCache.class,eviction=MybatisRedisCache.class)
public interface WeChatUserListMapper extends BaseMapper<WeChatUser>{
}