Mybatis：整合Redis缓存

Mybatis：整合Redis缓存

配置

import lombok.extern.slf4j.Slf4j;
import org.apache.ibatis.cache.Cache;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.data.redis.core.RedisCallback;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.connection.RedisServerCommands;
import org.springframework.util.CollectionUtils;

import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;

@Slf4j
public class MybatisRedisCache implements Cache {


    // 读写锁
    private final ReadWriteLock readWriteLock = new ReentrantReadWriteLock(true);

    //这里使用了redis缓存，使用springboot自动注入
    @Autowired
    @Qualifier("redisTemplate3")
    private RedisTemplate<String, Object> redisTemplate;

    private String id;

    public MybatisRedisCache(final 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) {
        if (redisTemplate == null) {
            //由于启动期间注入失败，只能运行期间注入，这段代码可以删除
            redisTemplate = (RedisTemplate<String, Object>) AppCtxUtils.getBean("redisTemplate3");
        }
        if (value != null) {
            redisTemplate.opsForValue().set(key.toString(), value);
        }
    }

    @Override
    public Object getObject(Object key) {
        try {
            if (key != null) {
                return redisTemplate.opsForValue().get(key.toString());
            }
        } catch (Exception e) {
            log.error("缓存数据不存在 ");
        }
        return null;
    }

    @Override
    public Object removeObject(Object key) {
        if (key != null) {
            redisTemplate.delete(key.toString());
        }
        return null;
    }

    @Override
    public void clear() {
        log.debug("清空缓存");
        if (redisTemplate == null) {
            redisTemplate = (RedisTemplate<String, Object>) AppCtxUtils.getBean("redisTemplate3");
        }
        Set<String> keys = redisTemplate.keys("*:" + this.id + "*");
        if (!CollectionUtils.isEmpty(keys)) {
            redisTemplate.delete(keys);
        }
    }

    @Override
    public int getSize() {
        Long size = redisTemplate.execute((RedisCallback<Long>) RedisServerCommands::dbSize);
        return size.intValue();
    }

    @Override
    public ReadWriteLock getReadWriteLock() {
        return this.readWriteLock;
    }
}

工具类

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

@Component
public class AppCtxUtils implements ApplicationContextAware {

    private static ApplicationContext appCtx;

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        appCtx = applicationContext;
    }

    public static <T> T getBean(Class<T> clazz) {
        return appCtx.getBean(clazz);
    }

    public static <T> T getBean(String beanName) {
        return (T) appCtx.getBean(beanName);
    }
}

使用

import org.apache.ibatis.annotations.CacheNamespace;

@CacheNamespace(implementation= MybatisRedisCache.class,eviction= MybatisRedisCache.class)
public interface DemoMapper {
}