spring整合redis缓存并以注解(@Cacheable、@CachePut、@CacheEvict)形式使用

maven项目中在pom.xml中依赖2个jar包，其他的spring的jar包省略：

<dependency>
  <groupId>redis.clients</groupId>
  <artifactId>jedis</artifactId>
  <version>2.8.1</version>
</dependency>
<dependency>
  <groupId>org.springframework.data</groupId>
  <artifactId>spring-data-redis</artifactId>
  <version>1.7.2.RELEASE</version>
</dependency> 

spring-Redis.xml中的内容：

<?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:p="http://www.springframework.org/schema/p"
  xmlns:context="http://www.springframework.org/schema/context"
  xmlns:mvc="http://www.springframework.org/schema/mvc"
  xmlns:cache="http://www.springframework.org/schema/cache"
  xsi:schemaLocation="http://www.springframework.org/schema/beans
            http://www.springframework.org/schema/beans/spring-beans-4.2.xsd
            http://www.springframework.org/schema/context
            http://www.springframework.org/schema/context/spring-context-4.2.xsd
            http://www.springframework.org/schema/mvc
            http://www.springframework.org/schema/mvc/spring-mvc-4.2.xsd
            http://www.springframework.org/schema/cache
            http://www.springframework.org/schema/cache/spring-cache-4.2.xsd">  

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

  <!-- 启用缓存注解功能，这个是必须的，否则注解不会生效，另外，该注解一定要声明在spring主配置文件中才会生效 -->
  <cache:annotation-driven cache-manager="cacheManager" />  

   <!-- redis 相关配置 -->
   <bean id="poolConfig" class="redis.clients.jedis.JedisPoolConfig">
     <property name="maxIdle" value="${redis.maxIdle}" />
     <property name="maxWaitMillis" value="${redis.maxWait}" />
     <property name="testOnBorrow" value="${redis.testOnBorrow}" />
   </bean>  

   <bean id="JedisConnectionFactory" class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory"
    p:host-name="${redis.host}" p:port="${redis.port}" p:password="${redis.pass}" p:pool-config-ref="poolConfig"/>  

   <bean id="redisTemplate" class="org.springframework.data.redis.core.RedisTemplate">
     <property name="connectionFactory" ref="JedisConnectionFactory" />
   </bean>  

   <!-- spring自己的缓存管理器，这里定义了缓存位置名称 ，即注解中的value -->
   <bean id="cacheManager" class="org.springframework.cache.support.SimpleCacheManager">
     <property name="caches">
      <set>
        <!-- 这里可以配置多个redis -->
        <!-- <bean class="com.cn.util.RedisCache">
           <property name="redisTemplate" ref="redisTemplate" />
           <property name="name" value="default"/>
        </bean> -->
        <bean class="com.cn.util.RedisCache">
           <property name="redisTemplate" ref="redisTemplate" />
           <property name="name" value="common"/>
           <!-- common名称要在类或方法的注解中使用 -->
        </bean>
      </set>
     </property>
   </bean>  

</beans>

redis-config.properties中的内容：

# Redis settings
# server IP
redis.host=127.0.0.1
# server port
redis.port=6379
# server pass
redis.pass=
# use dbIndex
redis.database=0
# 控制一个pool最多有多少个状态为idle(空闲的)的jedis实例
redis.maxIdle=300
# 表示当borrow(引入)一个jedis实例时，最大的等待时间，如果超过等待时间(毫秒)，则直接抛出JedisConnectionException；
redis.maxWait=3000
# 在borrow一个jedis实例时，是否提前进行validate操作；如果为true，则得到的jedis实例均是可用的
redis.testOnBorrow=true

com.cn.util.RedisCache类中的内容：

package com.cn.util;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream; 

import org.springframework.cache.Cache;
import org.springframework.cache.support.SimpleValueWrapper;
import org.springframework.dao.DataAccessException;
import org.springframework.data.redis.connection.RedisConnection;
import org.springframework.data.redis.core.RedisCallback;
import org.springframework.data.redis.core.RedisTemplate; 

public class RedisCache implements Cache{ 

  private RedisTemplate<String, Object> redisTemplate;
  private String name;
  public RedisTemplate<String, Object> getRedisTemplate() {
    return redisTemplate;
  } 

  public void setRedisTemplate(RedisTemplate<String, Object> redisTemplate) {
    this.redisTemplate = redisTemplate;
  } 

  public void setName(String name) {
    this.name = name;
  } 

  @Override
  public String getName() {
    // TODO Auto-generated method stub
    return this.name;
  } 

  @Override
  public Object getNativeCache() {
   // TODO Auto-generated method stub
    return this.redisTemplate;
  } 

  @Override
  public ValueWrapper get(Object key) {
   // TODO Auto-generated method stub
   System.out.println("get key");
   final String keyf = key.toString();
   Object object = null;
   object = redisTemplate.execute(new RedisCallback<Object>() {
   public Object doInRedis(RedisConnection connection)
         throws DataAccessException {
     byte[] key = keyf.getBytes();
     byte[] value = connection.get(key);
     if (value == null) {
       return null;
      }
     return toObject(value);
     }
    });
    return (object != null ? new SimpleValueWrapper(object) : null);
   } 

   @Override
   public void put(Object key, Object value) {
    // TODO Auto-generated method stub
    System.out.println("put key");
    final String keyf = key.toString();
    final Object valuef = value;
    final long liveTime = 86400;
    redisTemplate.execute(new RedisCallback<Long>() {
      public Long doInRedis(RedisConnection connection)
          throws DataAccessException {
        byte[] keyb = keyf.getBytes();
        byte[] valueb = toByteArray(valuef);
        connection.set(keyb, valueb);
        if (liveTime > 0) {
          connection.expire(keyb, liveTime);
         }
        return 1L;
       }
     });
   } 

   private byte[] toByteArray(Object obj) {
     byte[] bytes = null;
     ByteArrayOutputStream bos = new ByteArrayOutputStream();
     try {
      ObjectOutputStream oos = new ObjectOutputStream(bos);
      oos.writeObject(obj);
      oos.flush();
      bytes = bos.toByteArray();
      oos.close();
      bos.close();
     }catch (IOException ex) {
        ex.printStackTrace();
     }
     return bytes;
    }  

    private Object toObject(byte[] bytes) {
     Object obj = null;
      try {
        ByteArrayInputStream bis = new ByteArrayInputStream(bytes);
        ObjectInputStream ois = new ObjectInputStream(bis);
        obj = ois.readObject();
        ois.close();
        bis.close();
      } catch (IOException ex) {
        ex.printStackTrace();
      } catch (ClassNotFoundException ex) {
        ex.printStackTrace();
      }
      return obj;
    } 

    @Override
    public void evict(Object key) {
     // TODO Auto-generated method stub
     System.out.println("del key");
     final String keyf = key.toString();
     redisTemplate.execute(new RedisCallback<Long>() {
     public Long doInRedis(RedisConnection connection)
          throws DataAccessException {
       return connection.del(keyf.getBytes());
      }
     });
    } 

    @Override
    public void clear() {
      // TODO Auto-generated method stub
      System.out.println("clear key");
      redisTemplate.execute(new RedisCallback<String>() {
        public String doInRedis(RedisConnection connection)
            throws DataAccessException {
         connection.flushDb();
          return "ok";
        }
      });
    } 

    @Override
    public <T> T get(Object key, Class<T> type) {
      // TODO Auto-generated method stub
      return null;
    } 

    @Override
    public ValueWrapper putIfAbsent(Object key, Object value) {
      // TODO Auto-generated method stub
      return null;
    } 

}

到了这一步，大部分人会想在web.xml的启动配置文件地方(context-param)加入了spring-redis.xml,让项目启动时加载这个配置文件吧，但是这样启动后注解不生效。

正确的做法是：web.xml中配置了servlet控制器：

<servlet>
 <servlet-name>SpringMVC</servlet-name>
 <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
 <init-param>
  <param-name>contextConfigLocation</param-name>
  <param-value>/WEB-INF/spring-mvc.xml</param-value>
 </init-param>
 <load-on-startup>1</load-on-startup>
 <async-supported>true</async-supported>
</servlet> 

在DispatcherServlet的初始化过程中，框架会在web应用的 WEB-INF文件夹下寻找名为spring-mvc.xml的配置文件，如果不指定的话，默认是applicationContext.xml

只需要在spring-mvc.xml文件中引入spring-redis配置文件即可，正如spring-redis.xml中的启用注解说的：<cache:annotation-driven cache-manager="cacheManager" />注解一定要声明在spring主配置文件中才会生效。

spring-mvc.xml内容，省略了spring与spring MVC整合的那部分：

<?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:p="http://www.springframework.org/schema/p"
  xmlns:context="http://www.springframework.org/schema/context"
  xmlns:mvc="http://www.springframework.org/schema/mvc"
  xsi:schemaLocation="http://www.springframework.org/schema/beans
            http://www.springframework.org/schema/beans/spring-beans-4.2.xsd
            http://www.springframework.org/schema/context
            http://www.springframework.org/schema/context/spring-context-4.2.xsd
            http://www.springframework.org/schema/mvc
            http://www.springframework.org/schema/mvc/spring-mvc-4.2.xsd">
  <!-- 自动扫描该包，使SpringMVC认为包下用了@controller注解的类是控制器 -->
  <context:component-scan base-package="com.cn" />  

  <!-- 引入同文件夹下的redis属性配置文件 -->
  <import resource="spring-redis.xml"/> 

</beans>

在service的实现类中：

@Service
public class UserServiceImpl implements UserService{ 

  @Autowired
  private UserBo userBo; 

  @Cacheable(value="common",key="'id_'+#id")
  public User selectByPrimaryKey(Integer id) {
    return userBo.selectByPrimaryKey(id);
  } 

  @CachePut(value="common",key="#user.getUserName()")
  public void insertSelective(User user) {
    userBo.insertSelective(user);
  } 

  @CacheEvict(value="common",key="'id_'+#id")
  public void deleteByPrimaryKey(Integer id) {
    userBo.deleteByPrimaryKey(id);
  }
}

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