SSM框架和Redis整合

Redis是完全開放免費的，遵守BSD協議，是一個高性能的Key-Value的數據庫，Redis具有以下三個特點：
1.Redis支持數據持久化，可以將內存的數據保存在磁盤上，重啓時可以再次使用。
2.Redis不僅僅支持簡單的Key-Value類型的數據，同時還提供了list，set，zset，hash等數據結構的存儲。
3.Redis支出數據的備份，即master-slave模式的數據備份。
Redis優勢：
1. 性能極高-Redis能讀的速度是110000次/s ， 寫的速度是 81000次/s
2. 豐富的數據類型，Redis支持二進制案例的Strings，Lists，Hashes，sets及Ordered Sets數據類型操作。
3. 原子：Redis的所有操作都是原子性的，意思就是要門成功執行要麼失敗完全不執行。單個操作是原子性的。多個操作也支持事務即原子性，通過MULT和EXEC指令包起來。
4. 豐富的特性 - Redis還支持 publish/subscribe，通知，key過期等等特性。
說了這麼多，Redis在項目中應該如何應用呢？
Step1. 在電腦中安裝一個Redis服務(方法有很多。大家可以自行百度)。
Step2.開啓Redis服務
打開cmd命令進入到安裝redis服務的文件夾中，然後執行redis-server.exe即可
開啓成功的界面如下：

Step3. 在項目中進行如下配置
首先在項目中建立redis.properties的配置文件，在配置文件中寫如下內容：

# Redis settings  
redis.host=127.0.0.1
redis.port=6379  
redis.pass=123456

redis.maxIdle=300  
redis.maxActive=600  
redis.maxWait=1000  
redis.testOnBorrow=true 

引入jar包

<!-- spring-redis實現 -->
    <dependency>
      <groupId>org.springframework.data</groupId>
      <artifactId>spring-data-redis</artifactId>
      <version>1.6.2.RELEASE</version>
    </dependency>
    <!-- redis客戶端jar -->
    <dependency>
      <groupId>redis.clients</groupId>
      <artifactId>jedis</artifactId>
      <version>2.8.0</version>
    </dependency>

在spring-dao.config的配置文件中進行如下配置：

 <!--引入redis.properties配置文件-->
    <context:property-placeholder location="classpath:redis.properties" ignore-unresolvable="true"/>
   <!--配置redis數據源-->
    <bean id="poolConfig" class="redis.clients.jedis.JedisPoolConfig">
        <property name="maxIdle" value="${redis.maxIdle}" />
        <property name="maxTotal" value="${redis.maxActive}" />
        <property name="maxWaitMillis" value="${redis.maxWait}" />
        <!--suppress SpringModelInspection -->
        <property name="testOnBorrow" value="${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>
    <bean id="redisCacheTransfer" class="cn.redis.util.RedisCacheTransfer">
        <property name="jedisConnectionFactory" ref="jedisConnectionFactory" />
    </bean>

建立箇中間類

import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;

import org.apache.ibatis.cache.Cache;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.data.redis.connection.jedis.JedisConnection;
import org.springframework.data.redis.connection.jedis.JedisConnectionFactory;
import org.springframework.data.redis.serializer.JdkSerializationRedisSerializer;
import org.springframework.data.redis.serializer.RedisSerializer;

import redis.clients.jedis.exceptions.JedisConnectionException;

/**
 * 
 * @描述: 使用第三方內存數據庫Redis作爲二級緩存
 * @版權: Copyright (c) 2016
 * @作者:
 * @版本: 1.0
 * @創建日期:
 * @創建時間:
 */
public class RedisCache implements Cache {

    private static final Logger logger = LoggerFactory.getLogger(RedisCache.class);

    private static JedisConnectionFactory jedisConnectionFactory;

    private final String id;

    /**
     * The {@code ReadWriteLock}.
     */
    private final ReadWriteLock readWriteLock = new ReentrantReadWriteLock();

    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 void clear() {
        JedisConnection connection = null;
        try {
            connection = jedisConnectionFactory.getConnection();
            connection.flushDb();
            connection.flushAll();
        } catch (JedisConnectionException e) {
            e.printStackTrace();
        } finally {
            if (connection != null) {
                connection.close();
            }
        }
    }

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

    @Override
    public Object getObject(Object key) {
        Object result = null;
        JedisConnection connection = null;
        try {
            connection = jedisConnectionFactory.getConnection();
            RedisSerializer<Object> serializer = new JdkSerializationRedisSerializer();
            result = serializer.deserialize(connection.get(serializer.serialize(key)));
        } catch (JedisConnectionException e) {
            e.printStackTrace();
        } finally {
            if (connection != null) {
                connection.close();
            }
        }
        return result;
    }

    @Override
    public ReadWriteLock getReadWriteLock() {
        // TODO Auto-generated method stub
        return this.readWriteLock;
    }

    @Override
    public int getSize() {
        int result = 0;
        JedisConnection connection = null;
        try {
            connection = jedisConnectionFactory.getConnection();
            result = Integer.valueOf(connection.dbSize().toString());
        } catch (JedisConnectionException e) {
            e.printStackTrace();
        } finally {
            if (connection != null) {
                connection.close();
            }
        }
        return result;
    }

    @Override
    public void putObject(Object key, Object value) {
        JedisConnection connection = null;
        try {
            connection = jedisConnectionFactory.getConnection();
            RedisSerializer<Object> serializer = new JdkSerializationRedisSerializer();
            connection.set(serializer.serialize(key), serializer.serialize(value));
        } catch (JedisConnectionException e) {
            e.printStackTrace();
        } finally {
            if (connection != null) {
                connection.close();
            }
        }
    }

    @Override
    public Object removeObject(Object key) {
        JedisConnection connection = null;
        Object result = null;
        try {
            connection = jedisConnectionFactory.getConnection();
            RedisSerializer<Object> serializer = new JdkSerializationRedisSerializer();
            result = connection.expire(serializer.serialize(key), 0);
        } catch (JedisConnectionException e) {
            e.printStackTrace();
        } finally {
            if (connection != null) {
                connection.close();
            }
        }
        return result;
    }

    public static void setJedisConnectionFactory(JedisConnectionFactory jedisConnectionFactory) {
        RedisCache.jedisConnectionFactory = jedisConnectionFactory;
    }

}

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.connection.jedis.JedisConnectionFactory;

/**
 * 
 * @描述: 靜態注入中間類

 */
public class RedisCacheTransfer 
{

    @Autowired
    public void setJedisConnectionFactory(JedisConnectionFactory jedisConnectionFactory) {
        RedisCache.setJedisConnectionFactory(jedisConnectionFactory);

    }

}

在啊mapper.xml中添加如下代碼：

    <cache eviction="LRU" type="com.nuo.cache.RedisCache" />

這樣就可以直接啓動項目了。