SSM框架下的redis缓存

Posted 2020-09-28 浮川之畔

基本SSM框架搭建：http://www.cnblogs.com/fuchuanzhipan1209/p/6274358.html

配置文件部分：

第一步：加入jar包

pom.xml

<!-- spring-redis实现 -->
        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-redis</artifactId>
            <version>1.6.2.RELEASE</version>
        </dependency>
        <!-- redis客户端jar -->
        <dependency>
            <groupId>redis.clients</groupId>
            <artifactId>jedis</artifactId>
            <version>2.8.0</version>
        </dependency>
        <!-- Ehcache实现,用于参考 -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-ehcache</artifactId>
            <version>1.0.0</version>
        </dependency>

主配置文件：applicationContext.xml

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:p="http://www.springframework.org/schema/p" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context"
    xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
        http://www.springframework.org/schema/beans/spring-beans-3.2.xsd 
        http://www.springframework.org/schema/mvc 
        http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd 
        http://www.springframework.org/schema/context 
        http://www.springframework.org/schema/context/spring-context-3.2.xsd 
        http://www.springframework.org/schema/aop 
        http://www.springframework.org/schema/aop/spring-aop-3.2.xsd 
        http://www.springframework.org/schema/tx 
        http://www.springframework.org/schema/tx/spring-tx-3.2.xsd ">

    <!-- 加载db.properties文件中的内容，db.properties文件中key命名要有一定的特殊规则 -->
    <!-- 引入数据库配置文件 -->
    <bean id="propertyConfigurer"
        class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="locations">
            <list>
                <value>classpath:db.properties</value>
                <value>classpath:redis.properties</value>
            </list>
        </property>
    </bean>
    <!-- redis数据源 -->
    <bean id="poolConfig" class="redis.clients.jedis.JedisPoolConfig">
        <property name="maxIdle" value="${redis.maxIdle}" />
        <property name="maxTotal" value="${redis.maxActive}" />
        <property name="maxWaitMillis" value="${redis.maxWait}" />
        <property name="testOnBorrow" value="${redis.testOnBorrow}" />
    </bean>
    <!-- Spring-redis连接池管理工厂 -->
    <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" />
    <!-- 使用中间类解决RedisCache.jedisConnectionFactory的静态注入，从而使MyBatis实现第三方缓存 -->
    <bean id="redisCacheTransfer" class="com.nuo.cache.RedisCacheTransfer">
        <property name="jedisConnectionFactory" ref="jedisConnectionFactory" />
    </bean>
    <!-- 配置数据源 ，dbcp -->

    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
        destroy-method="close">
        <property name="driverClassName" value="${jdbc.driver}" />
        <property name="url" value="${jdbc.url}" />
        <property name="username" value="${jdbc.username}" />
        <property name="password" value="${jdbc.password}" />
        <property name="maxActive" value="30" />
        <property name="maxIdle" value="5" />
    </bean>
    <!-- sqlSessionFactory -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!-- 数据库连接池 -->
        <property name="dataSource" ref="dataSource" />
        <!-- 加载mybatis的全局配置文件 -->
        <property name="configLocation" value="classpath:sqlMapConfig.xml" />
    </bean>
    <!-- mapper扫描器 -->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <!-- 扫描包路径，如果需要扫描多个包，中间使用半角逗号隔开 -->
        <property name="basePackage" value="com.nuo.mapper"></property>
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory" />
    </bean>

    <!-- service -->
    <bean id="PersonService" class="com.nuo.service.impl.PersonServiceImpl" />


    <!-- 事务管理器 对mybatis操作数据库事务控制，spring使用jdbc的事务控制类 -->
    <bean id="transactionManager"
        class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <!-- 数据源 dataSource在applicationContext-dao.xml中配置了 -->
        <property name="dataSource" ref="dataSource" />
    </bean>
    <!-- 通知 -->
    <tx:advice id="txAdvice" transaction-manager="transactionManager">
        <tx:attributes>
            <!-- 传播行为 -->
            <tx:method name="save*" propagation="REQUIRED" />
            <tx:method name="delete*" propagation="REQUIRED" />
            <tx:method name="insert*" propagation="REQUIRED" />
            <tx:method name="update*" propagation="REQUIRED" />
            <tx:method name="find*" propagation="SUPPORTS" read-only="true" />
            <tx:method name="get*" propagation="SUPPORTS" read-only="true" />
            <tx:method name="select*" propagation="SUPPORTS" read-only="true" />
        </tx:attributes>
    </tx:advice>

    <!-- aop -->
    <aop:config>
        <aop:advisor advice-ref="txAdvice"
            pointcut="execution(* com.nuo.service.impl.*.*(..))" />
    </aop:config>

</beans>

mybitas配置文件：

sqlMapConfig.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>

    <!-- 全局setting配置，根据需要添加 -->

    

    <!-- 配置mapper 由于使用spring和mybatis的整合包进行mapper扫描，这里不需要配置了。 必须遵循：mapper.xml和mapper.java文件同名且在一个目录 -->
    
    <!-- 配置mybatis的缓存，延迟加载等等一系列属性 -->
    <settings>

        <!-- 全局映射器启用缓存 *主要将此属性设置完成即可 -->
        <setting name="cacheEnabled" value="true" />

        <!-- 查询时，关闭关联对象即时加载以提高性能 -->
        <setting name="lazyLoadingEnabled" value="false" />

        <!-- 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" />

        <!-- 设置关联对象加载的形态，此处为按需加载字段(加载字段由SQL指 定)，不会加载关联表的所有字段，以提高性能 -->
        <setting name="aggressiveLazyLoading" value="true" />

    </settings>
    <!-- 配置别名 -->
    <typeAliases>
        <!-- 批量扫描别名 -->
        <package name="com.nuo.model" />
    </typeAliases>
    
    <!-- <mappers> </mappers> -->
</configuration>

redis配置：

redis.properties

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

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

 Java代码工具类部分

静态注入中间类

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

/**
 * 
 * @描述: 静态注入中间类

 */
public class RedisCacheTransfer 
{

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

}

第三方内存数据库Redis

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: 使用第三方内存数据库Redis作为二级缓存
 * @版权: Copyright (c) 2016
 * @作者:
 * @版本: 1.0
 * @创建日期:
 * @创建时间:
 */
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;
    }

}

Java代码 SQL语句部分

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="com.nuo.mapper.PersonMapper">
    <cache eviction="LRU" type="com.nuo.cache.RedisCache" />
    <resultMap type="Person" id="PersonMap">
        <id column="id" property="id"/>
        <result column="name" property="name"/>
        <result column="gender" property="gender"/>     
    </resultMap>
    <select id="getByName" parameterType="String" resultMap="PersonMap">
        <![CDATA[
            SELECT
                * 
            FROM 
                person
            WHERE 
                name = LOWER(#{name})
        ]]>
    </select>
    
    <insert id="addPerson" parameterType="Person">
        <![CDATA[
        insert into
          person(name,gender)
          values(#{name},#{gender});
        
        ]]>
    </insert>
    
    <select id="getById" parameterType="int" resultMap="PersonMap">
        <![CDATA[
            SELECT
                * 
            FROM 
                person
            WHERE 
                id = LOWER(#{id})
        ]]>
    </select>
    
</mapper>

关键部分：

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

执行验证

第一次执行sql查询：

第二次执行相同语句时，不再打印sql语句，说明直接从缓存中读取了数据。

 redis服务器查看