mybatis 整合redis作为二级缓存

核心关键在于定义一个RedisCache实现mytis实现的Cache接口

 **
  * @author tele
  * @Description RedisCache由于需要传入id, 由mybatis进行创建，所以如果需要为RedisCache注入RedisTemplateUtil，直接使用@Autowired无效
  * @create 2019-09-07
  */
 public class RedisCache implements Cache {

     private static RedisTemplateUtil templateUtil;

     public static void setTemplateUtil(RedisTemplateUtil templateUtil) {
         RedisCache.templateUtil = templateUtil;
     }

     //这个id实际是传入的mapper全限定名
     private final String id;

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

     public String getId() {
         return id;
     }

     public void putObject(Object key, Object value) {
         templateUtil.set(key, value);
     }

     public Object getObject(Object key) {
         return templateUtil.get(key);
     }

     public Object removeObject(Object key) {
         return null;
     }

     public void clear() {
         templateUtil.clear();
     }

     public int getSize() {
         return templateUtil.getSize();
     }

     public ReadWriteLock getReadWriteLock() {
         return null;
     }
 }

定义中间类，注入工具类

 @Component
 public class RedisCacheTransfer {
     @Autowired
     private RedisTemplateUtil redisTemplateUtil;

     @Autowired
     public void setRedisTemplateUtil(){
         RedisCache.setTemplateUtil(redisTemplateUtil);
     }
 }

工具类

 /**
  * @author tele
  * @Description
  * @create 2019-09-09
  */
 @Component
 public class RedisTemplateUtil {
     @Autowired
     private RedisTemplate template;

     public Object get(Object key) {
         return template.opsForValue().get(key);
     }

     public void set(Object key,Object value){
         template.opsForValue().set(key, value);
     }

     public int getSize() {
       int size = (int) template.execute((RedisCallback<Integer>) connection -> {
             return connection.dbSize().intValue();
       });
       return size;
     }

     public void clear() {
         template.execute((RedisCallback)  connection -> {
             connection.flushDb();
             return null;
         });
     }
 }

在对应的mapper.xml中添加cache标签

测试的时候还是先加载ClassPathXmlContext，然后获得sqlSession，注意mybatis的增删改，flushCache=true，可如果你没有调用commit并不会清空缓存

applicationContext.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <beans xmlns="http://www.springframework.org/schema/beans"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns:context="http://www.springframework.org/schema/context"
        xmlns:p="http://www.springframework.org/schema/p"
        xmlns:tx="http://www.springframework.org/schema/tx"
        xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/cache http://www.springframework.org/schema/cache/spring-cache.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">

     <context:component-scan base-package="cn.tele"/>

     <context:property-placeholder location="classpath:redis.properties,db.properties"/>

     <!--数据源-->
     <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
         <property name="jdbcUrl" value="${db.url}"/>
         <property name="driverClass" value="${db.driver}"/>
         <property name="user" value="${db.username}"/>
         <property name="password" value="${db.password}"/>
         <property name="initialPoolSize" value="${db.initialPoolSize}"/>
         <property name="maxPoolSize" value="${db.maxPoolSize}"/>
         <property name="maxIdleTime" value="${db.maxIdleTime}"/>
         <property name="idleConnectionTestPeriod" value="${db.idleConnectionTestPeriod}"/>
         <property name="testConnectionOnCheckout" value="true"/>
       </bean>

     <!--mybatis-->
     <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
         <property name="mapperLocations" value="classpath*:cn/tele/bean/**/*.xml"/>
         <property name="dataSource" ref="dataSource"/>
         <property name="configurationProperties">
             <props>
                 <prop key="cacheEnabled">true</prop>
                 <prop key="jdbcTypeForNull">NULL</prop>
                 <prop key="lazyLoadingEnabled">true</prop>
                 <prop key="aggressiveLazyLoading">false</prop>
             </props>
         </property>
     </bean>

     <!--扫描mapper-->
     <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
         <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
         <property name="basePackage" value="cn.tele"/>
     </bean>

     <!--redis连接池属性设置-->
     <bean id="poolConfig" class="redis.clients.jedis.JedisPoolConfig">
         <property name="maxIdle" value="${redis.maxIdle}"/>
         <property name="maxTotal" value="${redis.maxTotal}"/>
     </bean>

     <bean id="jedisConnFactory"
           class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory"
           p:poolConfig-ref="poolConfig"  p:port="${redis.port}" p:hostName="${redis.host}"/>

     <bean id="redisTemplate"
           class="org.springframework.data.redis.core.StringRedisTemplate"
           p:connection-factory-ref="jedisConnFactory">
         <!--序列化策略-->
         <property name="keySerializer">
             <bean class="org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer">
                 <constructor-arg type="java.lang.Class" value="java.lang.String"/>
             </bean>
         </property>

         <property name="valueSerializer">
             <bean class="org.springframework.data.redis.serializer.JdkSerializationRedisSerializer">

             </bean>
         </property>

         <property name="hashKeySerializer">
             <bean class="org.springframework.data.redis.serializer.JdkSerializationRedisSerializer"/>
         </property>

         <property name="hashValueSerializer">
             <bean class="org.springframework.data.redis.serializer.JdkSerializationRedisSerializer"/>
         </property>
     </bean>
 </beans>