SSM整合redis做Mybatis二级缓存

一、准备相关jar包

<dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-redis</artifactId>
            <version>1.8.4.RELEASE</version>
<dependency/>
<dependency>
            <groupId>redis.clients</groupId>
            <artifactId>jedis</artifactId>
            <version>2.9.0</version>
</dependency>

二、开启Mybatis二级缓存

 <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">

        <property name="dataSource" ref="dataSource"/>
        <property name="typeAliasesPackage" value="com.yebin.domain"/>
        <property name="mapperLocations" value="classpath:mapper/*.xml"/>

        <!--配置mybatis日志信息-->
        <property name="configuration">
            <bean class="org.apache.ibatis.session.Configuration">
                <property name="logImpl" value="org.apache.ibatis.logging.stdout.StdOutImpl"/>
                <!--开启二级缓存-->
                <property name="cacheEnabled" value="true"/>
                <property name="aggressiveLazyLoading" value="true"/>
            </bean>
        </property>
</bean>        

我这里由于整合了Spring 所以去掉了Mybatis配置文件，直接在Spring-mybatsi中进行配置

三、redis相关配置

 <context:property-placeholder location="classpath:redis.properties" ignore-unresolvable="true"/>




    <bean id="poolConfig" class="redis.clients.jedis.JedisPoolConfig">
        <property name="maxTotal" value="${redis.maxTotal}"/>
        <property name="maxIdle" value="${redis.maxIdle}"/>
        <property name="maxWaitMillis" value="${redis.maxWaitMillis}"/>
    </bean>



     <bean id="connectionFactory" class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory">
         <property name="hostName" value="${redis.host}"/>
         <property name="poolConfig" ref="poolConfig"/>
         <property name="password" value="${redis.password}"/>
         <property name="port" value="${redis.port}"/>
     </bean>




    <!-- redis模板配置 -->
    <bean id="redisTemplate" class="org.springframework.data.redis.core.RedisTemplate">
        <property name="connectionFactory" ref="connectionFactory"></property>
        <!-- 对于中文的存储 需要进行序列化操作存储  序列化器  -->
        <property name="keySerializer">
            <bean class="org.springframework.data.redis.serializer.StringRedisSerializer"/>
        </property>
        <property name="valueSerializer">
            <bean id="jsonRedisSerializer" class="org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer">
                <!-- 使用默认的 ObjectMapper，移除JSON格式化后的 “@Class”节点 -->
                <constructor-arg name="mapper">
                    <bean class="com.fasterxml.jackson.databind.ObjectMapper"/>
                </constructor-arg>
            </bean>
        </property>
    </bean>


     <bean  class="org.springframework.data.redis.cache.RedisCacheManager">

         <constructor-arg name="redisOperations" ref="redisTemplate"/>
         <!--<property name="defaultExpiration" value="${redis.expiration}" />-->
     </bean>



    <bean class="com.yebin.config.RedisCacheTransfer">

    </bean>

Spring-data-redis-1.x采用如下配置，但Spring-data-redis2.x就不能这样配置了，在Spring-data-redis2.x中我们分单机和分布式来配置，由于我在这里只演示单机的，所以只配置单机版的：

<bean id="redisPassword" class="org.springframework.data.redis.connection.RedisPassword">
<constructor-arg  index="0" value="${redis.password}"></constructor-arg>
</bean>


Spring-data-redis 2.0以上配置
<bean id="redisStandaloneConfiguration" class="org.springframework.data.redis.connection.RedisStandaloneConfiguration">
<property name="hostName" value="${redis.host}"/>
<property name="port" value="${redis.port}"/>
<property name="password" ref="redisPassword" />
<property name="database" value="${redis.index}"/>
</bean>


Spring-data-redis 2.0以上配置
<bean id="connectionFactory" class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory">
<constructor-arg  name="standaloneConfig" ref="redisStandaloneConfiguration"/>
</bean>


Spring-data-redis 2.0以上配置
<bean  id="cacheManager" class="org.springframework.data.redis.cache.RedisCacheManager">

  <constructor-arg index="0" >
      <bean class="org.springframework.data.redis.cache.DefaultRedisCacheWriter">
          <constructor-arg ref="connectionFactory"/>
      </bean>
  </constructor-arg>
  <constructor-arg index="1">
      <bean class="org.springframework.data.redis.cache.RedisCacheConfiguration" factory-method="defaultCacheConfig" >
      </bean>
  </constructor-arg>

四、实现Cache接口

Cache接口是Mybatis提供的一个接口，如果需要使用第三方来做mybatis的缓存就需要去实现这个接口

public class RedisCache implements Cache {
    private final ReadWriteLock readWriteLock = new ReentrantReadWriteLock();
    private String id;


    private static RedisTemplate redisTemplate;

    public RedisCache(String id) {
        if (id == null) {
            throw new IllegalArgumentException("Cache instances require an ID");
        }

        this.id = id;
    }

    /**
     * 清除所有数据
     */
    @Override
    public void clear() {
        Set keys = redisTemplate.keys("*");
        redisTemplate.delete(keys);
    }

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

    /**
     * 得到指定key的 value
     *
     * @param key
     * @return object
     */
    @Override
    public Object getObject(Object key) {
        Object result = null;
        result = redisTemplate.opsForValue().get(key.toString());
        return result;
    }

    /**
     * 得到当前db的key值
     *
     * @return int
     */
    @Override
    public int getSize() {

        Set keys = redisTemplate.keys("*");

        return keys.size();
    }

        @Override
        public void putObject (Object key, Object value){

             System.out.print("key="+key);
            redisTemplate.opsForValue().set(key.toString(),value);
        }

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

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



        public  static  void setRedisTemplate(RedisTemplate template)
        {
             RedisCache.redisTemplate=template;
        }

    }

我这里配置了连个序列化器，一个是对Key的序列化器StringRedisSerializer，还有一个是对value的序列化器GenericJackson2JsonRedisSerializer，所以缓存的数据以JSON格式保存在redis数据库中

最后对要缓存的Mapper进行设置

<mapper namespace="com.yebin.mapper.PhoneMapper">    
    <cache type="com.yebin.config.RedisCache" ></cache>
</mapper>