mybatisplus自定义redis二级缓存

MybatisPlus自带的二级缓存默认使用了EHCache作为缓存实现，但在一些场景下可能需要使用Redis作为缓存实现。本文将介绍如何在MybatisPlus中自定义Redis二级缓存。

1. 引入Redis相关依赖

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-redis</artifactId>
    <version>2.2.2.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-pool2</artifactId>
    <version>2.6.2</version>
</dependency>

2. 自定义RedisCache

public class RedisCache implements Cache {
    private String id;
 
    private static RedisTemplate<String, Object> redisTemplate;
 
    public RedisCache(String id) {
        this.id = id;
        initRedisTemplate();
    }
 
    private void initRedisTemplate() {
        if (redisTemplate == null) {
            synchronized (RedisCache.class) {
                if (redisTemplate == null) {
                    redisTemplate = (RedisTemplate<String, Object>) ApplicationContextHolder.getBean("redisTemplate");
                }
            }
        }
    }
 
    @Override
    public String getId() {
        return id;
    }
 
    @Override
    public void putObject(Object key, Object value) {
        redisTemplate.opsForHash().put(id, key.toString(), value);
    }
 
    @Override
    public Object getObject(Object key) {
        return redisTemplate.opsForHash().get(id, key.toString());
    }
 
    @Override
    public Object removeObject(Object key) {
        redisTemplate.opsForHash().delete(id, key.toString());
        return null;
    }
 
    @Override
    public void clear() {
        redisTemplate.delete(id);
    }
 
    @Override
    public int getSize() {
        return redisTemplate.opsForHash().size(id).intValue();
    }
 
    @Override
    public ReadWriteLock getReadWriteLock() {
        return null;
    }
}

3. 自定义RedisCacheFactory

public class RedisCacheFactory implements CacheFactory {
    private static final Map<String, Cache> caches = new ConcurrentHashMap<>(16);
 
    private static RedisTemplate<String, Object> redisTemplate;
 
    public RedisCacheFactory() {
        initRedisTemplate();
    }
 
    private void initRedisTemplate() {
        if (redisTemplate == null) {
            synchronized (RedisCacheFactory.class) {
                if (redisTemplate == null) {
                    redisTemplate = (RedisTemplate<String, Object>) ApplicationContextHolder.getBean("redisTemplate");
                }
            }
        }
    }
 
    @Override
    public Cache getCache(String id) {
        Cache cache = caches.get(id);
        if (cache == null) {
            cache = new RedisCache(id);
            caches.put(id, cache);
        }
        return cache;
    }
 
    @Override
    public Set<String> getCacheNames() {
        return caches.keySet();
    }
}

4. 配置MybatisPlus

@Configuration
public class MybatisPlusConfig {
    @Autowired
    private RedisCacheFactory redisCacheFactory;
 
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor() throws Exception {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        Properties props = new Properties();
        props.setProperty("cache-enabled", "true");
        props.setProperty("local-cache-scope", "STATEMENT");
        props.setProperty("local-cache-ref", "local-cache");
        // 自定义RedisCacheFactory
        props.setProperty("second-level-cache-enabled", "true");
        props.setProperty("second-level-cache-type", "org.apache.ibatis.cache.decorators.RedisCache");
        interceptor.addInnerInterceptor(new CacheInterceptor(props, redisCacheFactory));
        return interceptor;
    }
}

完成上述步骤后，即可在MybatisPlus中使用自定义的Redis二级缓存。