Mybatis 使用Redis 作为二级缓存_综合

Mybatis 开启二级缓存，使用 Redis 去实现 cache 进行缓存处理，这样就不用一直去请求数据库，降低数据库的压力，并且查询也会快一点
设置mybatis 开启二级缓存

<setting name="cacheEnabled" value="true"/>

Redis 工具类：

public class JedisPoolUtil {private JedisPoolUtil() {}public static volatile JedisPool jedisPool = null;public static JedisPool getJedisPoolInstance(){if(null == jedisPool){synchronized (JedisPoolUtil.class) {if(null == jedisPool){JedisPoolConfig poolConfig = new JedisPoolConfig();
//                    poolConfig.setMaxActive(1000);poolConfig.setMaxIdle(32);
//                    poolConfig.setMaxWait(1000*100);poolConfig.setTestOnBorrow(true);jedisPool = new JedisPool(poolConfig ,"127.0.0.1",6379,100,"root");}}}return jedisPool;}
}

RedisCache：实现cache


public class RedisCache implements Cache {private static final Logger logger = LoggerFactory.getLogger(RedisCache.class);private final ReadWriteLock readWriteLock = new ReentrantReadWriteLock();// cache instance idprivate final String id;public RedisCache(String id) {this.id = id;}@Overridepublic String getId() {return id;}@Overridepublic void putObject(Object key, Object value) {try {JedisPool jedisPoolInstance = JedisPoolUtil.getJedisPoolInstance();logger.debug("put cached query result from redis");jedisPoolInstance.getResource().set(key.toString(),value.toString());} catch (Throwable t) {logger.error("Redis put failed, fail over to db", t);}}@Overridepublic Object getObject(Object key) {try {JedisPool jedisPoolInstance = JedisPoolUtil.getJedisPoolInstance();logger.debug("Get cached query result from redis");return jedisPoolInstance.getResource().get(key.toString());} catch (Throwable t) {logger.error("Redis get failed, fail over to db", t);return null;}}@Overridepublic Object removeObject(Object key) {try {JedisPool jedisPoolInstance = JedisPoolUtil.getJedisPoolInstance();logger.debug("remove cached query result from redis");return jedisPoolInstance.getResource().del(key.toString());} catch (Throwable t) {logger.error("Redis remove failed, fail over to db", t);return null;}}@Overridepublic void clear() throws CacheException {try {JedisPool jedisPoolInstance = JedisPoolUtil.getJedisPoolInstance();logger.debug("clear cached query result from redis");jedisPoolInstance.getResource().flushDB();} catch (Throwable t) {logger.error("Redis clear failed, fail over to db", t);}}@Overridepublic int getSize() {return 0;}@Overridepublic ReadWriteLock getReadWriteLock() {return readWriteLock;}
}

在xml中使用：

    <cache type="cn.jeeweb.core.cache.RedisCache"><property name="eviction" value="LRU"/><property name="flushInterval" value="60000000"/><property name="size" value="2048"/><property name="readOnly" value="false"/></cache>

最后，在过程中出现过一些小的错误，希望记录下来

Caused by: java.lang.ClassCastException: cn.jeeweb.core.cache.RedisCache cannot be cast to org.apache.ibatis.cache.Cache

这个错误，是因为项目中时用 shiro 做权限框架，导致导入cache包时导入错误，应该导入 org.apache.ibatis.cache.Cache 包才对

Caused by: java.lang.NoSuchMethodException: cn.jeeweb.core.cache.RedisCache.<init>(java.lang.String)

这个是因为cache 需要一个构造id

Mybatis 使用Redis 作为 二级缓存

Mybatis 使用Redis 作为二级缓存