Redis 初探
Posted 叶乐乐
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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。
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