Redis 初探

周围的人似乎都会redis,我就想看看redis究竟是什么。下面推荐一个学习网站。http://www.runoob.com/ 这个网站有很多基础的课程。在看我的文章之前，你可去这个网站看看redia的基础知识。

本文是把redis最为mysql的缓存来使用的。本文是用的spring-data-redis ,ComboPooledDataSource（数据库连接池）,mysql数据库。重点是spring-data-redis 中五种数据基本类型的基本操作，以及redis作为缓存对查询速度的提升。

1.首先是搭建环境

   spring-mvc.xml  主要配置了mysql和redis<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: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-4.0.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd">
    <!-- class annotation related... start -->
    <context:component-scan base-package="com.test"/>
    <context:component-scan base-package="com.test.service" />
    <context:component-scan base-package="com.test.cache.redis" />
    <!-- class annotation related... end -->
    <context:annotation-config />
    <!-- mybatis related... start -->
    <bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="locations">
            <list>
                <!-- 这里支持多种寻址方式：classpath和file -->
                <value>classpath:jdbc.properties</value>
                <value>classpath:redis.properties</value>
                <!-- 推荐使用file的方式引入，这样可以将配置和代码分离 -->
            </list>
        </property>
    </bean>


    <!--数据库连接配置-->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource "
          destroy-method="close">
        <property name="driverClass" value="${jdbc.driver}" />
        <property name="jdbcUrl" value="${jdbc.url}" />
        <property name="user" value="${jdbc.username}" />
        <property name="password" value="${jdbc.password}" />
        <property name="acquireIncrement" value="1" />
        <property name="initialPoolSize" value="5" />
        <property name="maxPoolSize" value="20" />
        <property name="minPoolSize" value="5" />
        <property name="maxStatements" value="100" />
        <property name="testConnectionOnCheckout" value="true" />
    </bean>
    
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="configLocation" value="classpath:mybatis-config.xml" />
    </bean>
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.test.mapper"/>
    </bean>
    <!-- mybatis related... end -->

    <!-- transaction config related... start -->
    <tx:annotation-driven transaction-manager="transactionManager" />
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource" />
    </bean>
    <!-- transaction config related... end -->

    <!-- redis  config  start -->
    <!-- 配置JedisPoolConfig实例 -->
    <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>

    <!-- 配置JedisConnectionFactory -->
    <bean id="jedisConnectionFactory" class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory">
        <property name="hostName" value="${redis.host}"/>
        <property name="port" value="${redis.port}"/>
        <property name="password" value="${redis.pass}"/>
        <property name="database" value="${redis.dbIndex}"/>
        <property name="poolConfig" ref="poolConfig"/>
    </bean>

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

    <!-- 配置RedisCacheManager -->
    <bean id="redisCacheManager" class="org.springframework.data.redis.cache.RedisCacheManager">
        <constructor-arg name="redisOperations" ref="redisTemplate" />
        <property name="defaultExpiration" value="${redis.expiration}"/>
    </bean>

    <!-- 配置RedisCacheConfig -->
    <bean id="redisCacheConfig" class="com.test.cache.redis.RedisCacheConfig">
        <constructor-arg ref="jedisConnectionFactory" />
        <constructor-arg ref="redisTemplate" />
        <constructor-arg ref="redisCacheManager" />
    </bean>

    <!-- redis  config  end -->
</beans>


spring-servlet.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:p="http://www.springframework.org/schema/p"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:aop="http://www.springframework.org/schema/aop" xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans

http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd">
    <!-- 启用spring mvc 注解 -->
    <context:annotation-config />
    <!-- class annotation related... start -->
    <context:component-scan base-package="com.test.action" />
    <!-- class annotation related... end -->

    <aop:config proxy-target-class="true">
    </aop:config>

    <!-- rest json related... start -->
    <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
    </bean>
    <!-- rest json related... end -->

    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/jsp/" />
        <property name="suffix" value=".jsp" />
    </bean>
    <!-- jsp page related... end -->
</beans>

还有redis的连接配置，redis.properties

# Redis settings
redis.host=127.0.0.1
redis.port=6369  
redis.pass=
redis.dbIndex=0  
redis.expiration=3000  


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

还有jdbc.properties

jdbc.driver = com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3307/ssms?useUnicode=true&characterEncoding=utf8
jdbc.username=root
jdbc.password=root 

然后是web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xmlns="http://java.sun.com/xml/ns/javaee"
         xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
         id="WebApp_ID" version="3.0">
  <display-name>Archetype Created Web Application</display-name>

  <!-- character encoding related.....start --><!-- TODO : 将 encodingFilter、sysParamsFilter 两个过滤器交给 spring 管理 -->
  <filter>
    <filter-name>encodingFilter</filter-name>
    <filter-class>
      org.springframework.web.filter.CharacterEncodingFilter
    </filter-class>
    <init-param>
      <param-name>encoding</param-name>
      <param-value>UTF-8</param-value>
    </init-param>
    <init-param>
      <param-name>forceEncoding</param-name>
      <param-value>true</param-value>
    </init-param>
  </filter>
  <filter-mapping>
    <filter-name>encodingFilter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>

  <!-- 除了加过滤器，由于tomcat默认编码ISO-8859-1，还需要修改 %tomcat%/conf/server.xml Connector 标签加属性 URIEncoding="UTF-8" -->
  <!-- character encoding related.....end -->


  <servlet>
    <servlet-name>mvc-servlet</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>classpath:spring-servlet.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
    <servlet-name>mvc-servlet</servlet-name>
    <url-pattern> *.do</url-pattern>
  </servlet-mapping>


  <listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
  </listener>

  <context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath:applicationContext.xml</param-value>
  </context-param>

</web-app>


还有最重要的pom.xml配置文件

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.metaedu</groupId>
  <artifactId>Spring-Redis</artifactId>
  <packaging>war</packaging>
  <version>1.0-SNAPSHOT</version>
  <name>Spring-Redis Maven Webapp</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <spring.version>4.2.0.RELEASE</spring.version>
  </properties>

    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.12</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-test</artifactId>
      <version>4.2.5.RELEASE</version>
      <scope>test</scope>
    </dependency>

    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-aop</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-webmvc</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-web</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>jstl</artifactId>
      <version>1.2</version>
    </dependency>
     <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <version>3.0.1</version>
    </dependency>
    <dependency>
      <groupId>commons-logging</groupId>
      <artifactId>commons-logging</artifactId>
      <version>1.1.3</version>
    </dependency>
    <dependency>
      <groupId>org.codehaus.jackson</groupId>
      <artifactId>jackson-mapper-asl</artifactId>
      <version>1.9.13</version>
    </dependency>
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-annotations</artifactId>
      <version>2.6.1</version>
    </dependency>
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-core</artifactId>
      <version>2.6.1</version>
    </dependency>
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-databind</artifactId>
      <version>2.6.1</version>
    </dependency>
    <!-- spring mvc related.....end -->

    <!-- mybatis orm related.....start -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-orm</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis-spring</artifactId>
      <version>1.2.3</version>
    </dependency>
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.36</version>
    </dependency>
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>3.3.0</version>
    </dependency>
    <dependency>
      <groupId>c3p0</groupId>
      <artifactId>c3p0</artifactId>
      <version>0.9.1.2</version>
    </dependency>
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-log4j12</artifactId>
      <version>1.7.12</version>
    </dependency>
    <!-- mybatis orm related.....end -->

    <!-- project log related.....start -->
    <dependency>
      <groupId>log4j</groupId>
      <artifactId>log4j</artifactId>
      <version>1.2.17</version>
    </dependency>
    <!-- project log related.....end -->

    <!-- redis cache related.....start -->
    <dependency>
      <groupId>org.springframework.data</groupId>
      <artifactId>spring-data-redis</artifactId>
      <version>1.6.0.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>redis.clients</groupId>
      <artifactId>jedis</artifactId>
      <version>2.7.3</version>
    </dependency>
    <!-- redis cache related.....end -->
  </dependencies>

2.生成测试类

redis在本例中只是作为mybatis的缓存,主要还是做查询的优化。


我们要先写一个usermapper.xml

然后，我们还需要写一个RedisService来测试这些查询。

package com.test.service;

import org.springframework.data.redis.core.*;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;

@Service
public class RedisService {

    @Resource
    private RedisTemplate<String,Object> redisTemplate;

    public ValueOperations<String,Object> valueOperations;

    public SetOperations<String,Object> setOperations;

    public ZSetOperations<String,Object> zSetOperations;

    public HashOperations<String,String,Object> hashOperations;

    public  ListOperations<String,Object> listOperations;





    public  ValueOperations<String,Object> ValueOperationsNewInstance(){
        if(valueOperations==null){
            valueOperations = redisTemplate.opsForValue();
        }
        return valueOperations;
    }
    public  ListOperations<String,Object> listOperationsNewInstance(){
        if(listOperations==null){
            listOperations = redisTemplate.opsForList();
        }
        return listOperations;
    }

     public  HashOperations <String,String,Object> hashOperationsNewInstance(){
        if(hashOperations == null){
            hashOperations = redisTemplate.opsForHash();
        }
        return  hashOperations;
     }


     public   SetOperations<String,Object> setOperationsNewInstance(){
         if(setOperations == null){
             setOperations = redisTemplate.opsForSet();
         }
         return  setOperations;
     }

    public ZSetOperations<String, Object> ZsetOperationsNewInstance() {
         if(zSetOperations==null){
             zSetOperations = redisTemplate.opsForZSet();
         }
        return zSetOperations;
    }

    public   void  Delete(String  key){
         redisTemplate.delete(key);

    }


在redisService中最重要的是RedisTemplate，这个类我们之前在spring-mvc.xml中已经配置过了。这个类会为我们生成redis五种基本数据类型的操作类。

我们可以自己生成一个测试类来实际操作下这五种基本类型。以下是我的测试类：

这里要使用springJunitTest，不要单独使用junit，因为我们的RedisTemplate是配置在文档里面的。

我们来看下这五种基本数据类型的操作：

1.String（redis） ----》ValueOperations(spriing-data-redis) 

ValueOperations valueOperations =  redisTemplate.opsForValue();

以下是测试类（我们根据时间差来查看redis的缓存效果）：

下面是用ValueOperations保存数据并取出数据的操作：

 下面是运行结果：

2.Hash(redis)  --->HashOperations(spring-data-redis)

HashOperations hashOperations = redisTemplate.opsForHash();

下面是测试类（我们根据时间差来查看redis的缓存效果）：

下面是用HashOperations保存并取出数据的操作：

以下是运行结果;

3.list(redis) --->ListOperations(spring-data-redis)

ListOperations  listOperations = redisTemplate.opsForList();

 留给读者自己去实践。。。。

4.set(redis) --->SetOperations(spring-data-redis)

SetOperations setOperations = redisTemplate.opsForSet();

 留给读者自己去实践。。。。。

5.zset(redis) --->ZSetOperations(spring-data-redis)

ZSetOperations  zSetOperations = redisTemplate.opsForZSet();

zSetOperation  实际上就是一个有序的set 。

下面是测试类（我们根据时间差来查看redis的缓存效果）：

下面是用ZSetOperations 来保存数据并取出的操作：

public User  findUserById(String id){
    //查看缓存有没有数据 
    if (redisService.ZsetOperationsNewInstance().range(id,0,-1).size()==0){
        //缓存中没有就从数据库中取出
        User user = usermapper.findUserById(id);
        //并保存到redis缓存中（ZSet保存）
        redisService.ZsetOperationsNewInstance().add(id,user,Double.valueOf(id));
        System.out.println("数据库查询  用户名" +user.getUsername());
        return user;
    }else{
        //如果缓存中有，就从缓存中取出
        Set<Object>  users= redisService.ZsetOperationsNewInstance().range(id,0,-1);
        Iterator<Object> it = users.iterator();
        while(it.hasNext()){
            Object object= it.next();
            User  user  = (User) object;
            System.out.println("Redis查询  用户名" +user.getUsername());
            return  user;
        }
         return null;
    }
}

我们来看下运行结果：

 3.结论

 从上面的运行结果中，我们可以看到redis大大提高了我们的查询速度。另外在测试的时候。redis不允许有重复的key，所以要记得删除。

关于redis更高深的东西，后续研究后再更新。