redis+mybatis+spring

redis的安装http://liuyieyer.iteye.com/blog/2078093

redis的主从高可用 http://liuyieyer.iteye.com/blog/2078095

Mybatis 的使用不多说。

Mybatis为了方便我们扩展缓存定义了一个Cache接口，看看ehcache-mybatis的源码就明白了。我们要使用自己的cache同样的实现Cache接口即可。直接上代码

public class RedisCache   implements Cache {
        private static Log logger = LogFactory.getLog(RedisCache.class);
        private Jedis redisClient = createClient();
        /** The ReadWriteLock. */
        private final ReadWriteLock readWriteLock = new ReentrantReadWriteLock();

        private String id;
        public RedisCache(final String id) {
                if (id == null) {
                        throw new IllegalArgumentException("Cache instances require an ID");
                }
                logger.debug(">>>>>>>>>>>>>>>>>>>>>>>>MybatisRedisCache:id=" + id);
                this.id = id;
        }

        @Override
        public String getId() {
                return this.id;
        }

        @Override
        public int getSize() {
                return Integer.valueOf(redisClient.dbSize().toString());
        }

        @Override
        public void putObject(Object key, Object value) {
                logger.debug(">>>>>>>>>>>>>>>>>>>>>>>>putObject:" + key + "=" + value);
                redisClient.set(SerializeUtil.serialize(key.toString()), SerializeUtil.serialize(value));
        }

        @Override
        public Object getObject(Object key) {
                Object value = SerializeUtil.unserialize(redisClient.get(SerializeUtil.serialize(key.toString())));
                logger.debug(">>>>>>>>>>>>>>>>>>>>>>>>getObject:" + key + "=" + value);
                return value;
        }

        @Override
        public Object removeObject(Object key) {
                return redisClient.expire(SerializeUtil.serialize(key.toString()), 0);
        }

        @Override
        public void clear() {
                redisClient.flushDB();
        }

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

        protected  static Jedis createClient() {
                try {
                        JedisPool pool = new JedisPool(new JedisPoolConfig(), "172.60.0.172");
                       return pool.getResource();
                } catch (Exception e) {
                        e.printStackTrace();
                }
                throw new RuntimeException("初始化连接池错误");
        }



}


class SerializeUtil {
        public static byte[] serialize(Object object) {
                ObjectOutputStream oos = null;
                ByteArrayOutputStream baos = null;
                try {
                        // 序列化
                        baos = new ByteArrayOutputStream();
                        oos = new ObjectOutputStream(baos);
                        oos.writeObject(object);
                        byte[] bytes = baos.toByteArray();
                        return bytes;
                } catch (Exception e) {
                        e.printStackTrace();
                }
                return null;
        }

        public static Object unserialize(byte[] bytes) {
                if(bytes == null)return null;
                ByteArrayInputStream bais = null;
                try {
                        // 反序列化
                        bais = new ByteArrayInputStream(bytes);
                        ObjectInputStream ois = new ObjectInputStream(bais);
                        return ois.readObject();
                } catch (Exception e) {
                        e.printStackTrace();
                }
                return null;
        }
}

 

在看ehcache-mybatis的源码 它真正使用cache的方式是通过集成org.apache.ibatis.cache.decorators.LoggingCache 这个类实现的，照猫画虎，直接我们也继承

public class LoggingRedisCache extends LoggingCache {

        public LoggingRedisCache(String id) {
                super(new RedisCache(id));
        }

}

 

在mapper.xml中添加如下cache标签

 

<!-- 启用缓存 -->
    <cache type="cn.seafood.cache.LoggingRedisCache" />

 在mybatis的核心文件中开启缓存

<settings>
    <!-- 这个配置使全局的映射器启用或禁用缓存 -->
    <setting name="cacheEnabled" value="true" />
 <!-- 对于未知的SQL查询，允许返回不同的结果集以达到通用的效果 -->
        <setting name="multipleResultSetsEnabled" value="true"/>
    <!-- 配置默认的执行器。SIMPLE 执行器没有什么特别之处。REUSE 执行器重用预处理语句。BATCH 执行器重用语句和批量更新 -->
    <setting name="defaultExecutorType" value="REUSE" />
    <!-- 全局启用或禁用延迟加载。当禁用时，所有关联对象都会即时加载。 -->
    <setting name="lazyLoadingEnabled" value="false" />
    <setting name="aggressiveLazyLoading" value="true" />
    <!-- <setting name="enhancementEnabled" value="true"/> -->
    <!-- 设置超时时间，它决定驱动等待一个数据库响应的时间。 -->
    <setting name="defaultStatementTimeout" value="25000" />
</settings>

 

<setting name="lazyLoadingEnabled" value="false" />

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

注意着两个属性，需要把属性延迟加载和关联对象加载给关闭了，不然放进redis中的cglib代理对象，在对数据发生更改的时候，会出错。

 

 

在上一篇文中的Cahe类存在各种问题如：一直使用同一个连接，每次都创建新的Cache，项目中老是爆出connection timeout 的异常，存储的key过长等等一系列的问题，解决问题最好的办法就是看源码和看官方的文档说明，jedis的文档还是够用的，接下来把cache也改造以下附上代码。

package cn.seafood.cache;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.ibatis.cache.Cache;

import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import redis.clients.jedis.JedisPoolConfig;
import redis.clients.jedis.exceptions.JedisConnectionException;
import cn.seafood.util.PropertiesLoader;

/**
 *
* @ClassName: RedisCache
* @Description: TODO(使用第三方缓存服务器redis，处理二级缓存)
* @author LiuYi
* @date 2014年6月9日 下午1:37:46
*
 */
public class RedisCache   implements Cache {
        private static Log log = LogFactory.getLog(RedisCache.class);
        /** The ReadWriteLock. */
        private final ReadWriteLock readWriteLock = new ReentrantReadWriteLock();

        private String id;
        public RedisCache(final String id) {
                if (id == null) {
                        throw new IllegalArgumentException("必须传入ID");
                }
                log.debug("MybatisRedisCache:id=" + id);
                this.id=id;
        }

        @Override
        public String getId() {
                return this.id;
        }

        @Override
        public int getSize() {
                Jedis jedis = null;
                JedisPool jedisPool = null;
                int result = 0;
                boolean borrowOrOprSuccess = true;
                try {
                        jedis   = CachePool.getInstance().getJedis();
                        jedisPool = CachePool.getInstance().getJedisPool();
                        result = Integer.valueOf(jedis.dbSize().toString());
                } catch (JedisConnectionException e) {
                        borrowOrOprSuccess = false;
                        if (jedis != null)
                                jedisPool.returnBrokenResource(jedis);
                } finally {
                        if (borrowOrOprSuccess)
                                jedisPool.returnResource(jedis);
                }
                return result;

        }

        @Override
        public void putObject(Object key, Object value) {
                if(log.isDebugEnabled())
                log.debug("putObject:" + key.hashCode() + "=" + value);
                if(log.isInfoEnabled())
                log.info("put to redis sql :" +key.toString());
                Jedis jedis = null;
                JedisPool jedisPool = null;
                boolean borrowOrOprSuccess = true;
                try {
                        jedis   = CachePool.getInstance().getJedis();
                        jedisPool = CachePool.getInstance().getJedisPool();
                        jedis.set(SerializeUtil.serialize(key.hashCode()), SerializeUtil.serialize(value));
                } catch (JedisConnectionException e) {
                        borrowOrOprSuccess = false;
                        if (jedis != null)
                                jedisPool.returnBrokenResource(jedis);
                } finally {
                        if (borrowOrOprSuccess)
                                jedisPool.returnResource(jedis);
                }

        }

        @Override
        public Object getObject(Object key) {
                Jedis jedis = null;
                JedisPool jedisPool = null;
                Object value = null;
                boolean borrowOrOprSuccess = true;
                try {
                        jedis   = CachePool.getInstance().getJedis();
                        jedisPool = CachePool.getInstance().getJedisPool();
                        value  = SerializeUtil.unserialize(jedis.get(SerializeUtil.serialize(key.hashCode())));
                } catch (JedisConnectionException e) {
                        borrowOrOprSuccess = false;
                        if (jedis != null)
                                jedisPool.returnBrokenResource(jedis);
                } finally {
                        if (borrowOrOprSuccess)
                                jedisPool.returnResource(jedis);
                }
                if(log.isDebugEnabled())
                log.debug("getObject:" + key.hashCode() + "=" + value);
                return value;
        }

        @Override
        public Object removeObject(Object key) {
                Jedis jedis = null;
                JedisPool jedisPool = null;
                Object value = null;
                boolean borrowOrOprSuccess = true;
                try {
                        jedis   = CachePool.getInstance().getJedis();
                        jedisPool = CachePool.getInstance().getJedisPool();
                        value  = jedis.expire(SerializeUtil.serialize(key.hashCode()), 0);
                } catch (JedisConnectionException e) {
                        borrowOrOprSuccess = false;
                        if (jedis != null)
                                jedisPool.returnBrokenResource(jedis);
                } finally {
                        if (borrowOrOprSuccess)
                                jedisPool.returnResource(jedis);
                }
                if(log.isDebugEnabled())
                log.debug("getObject:" + key.hashCode() + "=" + value);
                return value;
        }

        @Override
        public void clear() {
                Jedis jedis = null;
                JedisPool jedisPool = null;
                boolean borrowOrOprSuccess = true;
                try {
                        jedis   = CachePool.getInstance().getJedis();
                        jedisPool = CachePool.getInstance().getJedisPool();
                        jedis.flushDB();
                        jedis.flushAll();
                } catch (JedisConnectionException e) {
                        borrowOrOprSuccess = false;
                        if (jedis != null)
                                jedisPool.returnBrokenResource(jedis);
                } finally {
                        if (borrowOrOprSuccess)
                                jedisPool.returnResource(jedis);
                }
        }

        @Override
        public ReadWriteLock getReadWriteLock() {
                return readWriteLock;
        }
       /**
        *
       * @ClassName: CachePool
       * @Description: TODO(单例Cache池)
       * @author LiuYi
       * @date 2014年6月17日 上午10:50:52
       *
        */
        public static class CachePool {
                JedisPool pool;
                private static final CachePool cachePool = new CachePool();

                public static CachePool getInstance(){
                        return cachePool;
                }
                private CachePool() {
                        JedisPoolConfig config = new JedisPoolConfig();
                        config.setMaxIdle(100);
                        config.setMaxWaitMillis(1000l);
                         PropertiesLoader pl =  new PropertiesLoader("classpath:config/redis.properties");
                         pool = new JedisPool(config,pl.getProperty("redisvip"));
                }
                public  Jedis getJedis(){
                        Jedis jedis = null;
                        boolean borrowOrOprSuccess = true;
                        try {
                                jedis = pool.getResource();
                        } catch (JedisConnectionException e) {
                                borrowOrOprSuccess = false;
                                if (jedis != null)
                                        pool.returnBrokenResource(jedis);
                        } finally {
                                if (borrowOrOprSuccess)
                                        pool.returnResource(jedis);
                        }
                        jedis = pool.getResource();
                        return jedis;
                }

                public JedisPool getJedisPool(){
                        return this.pool;
                }

        }


        public static class SerializeUtil {
                public static byte[] serialize(Object object) {
                        ObjectOutputStream oos = null;
                        ByteArrayOutputStream baos = null;
                        try {
                                // 序列化
                                baos = new ByteArrayOutputStream();
                                oos = new ObjectOutputStream(baos);
                                oos.writeObject(object);
                                byte[] bytes = baos.toByteArray();
                                return bytes;
                        } catch (Exception e) {
                                e.printStackTrace();
                        }
                        return null;
                }

                public static Object unserialize(byte[] bytes) {
                        if(bytes == null)return null;
                        ByteArrayInputStream bais = null;
                        try {
                                // 反序列化
                                bais = new ByteArrayInputStream(bytes);
                                ObjectInputStream ois = new ObjectInputStream(bais);
                                return ois.readObject();
                        } catch (Exception e) {
                                e.printStackTrace();
                        }
                        return null;
                }
        }
}

 参考链接：http://liuyieyer.iteye.com/blog/2081382