SpringMVC项目中如何使用redis缓存技术

1:电脑上必须安装过Redis，然后启动它。

C:\Users\Administrator>e:

E:\>cd redsi
系统找不到指定的路径。

E:\>cd redis

E:\redis>redis-server.exe redis.windows.conf
                _._
           _.-``__ ''-._
      _.-``    `.  `_.  ''-._           Redis 2.8.9 (00000000/0) 64 bit
  .-`` .-```.  ```\/    _.,_ ''-._
 (    '      ,       .-`  | `,    )     Running in stand alone mode
 |`-._`-...-` __...-.``-._|'` _.-'|     Port: 6379
 |    `-._   `._    /     _.-'    |     PID: 1104
  `-._    `-._  `-./  _.-'    _.-'
 |`-._`-._    `-.__.-'    _.-'_.-'|
 |    `-._`-._        _.-'_.-'    |           http://redis.io
  `-._    `-._`-.__.-'_.-'    _.-'
 |`-._`-._    `-.__.-'    _.-'_.-'|
 |    `-._`-._        _.-'_.-'    |
  `-._    `-._`-.__.-'_.-'    _.-'
      `-._    `-.__.-'    _.-'
          `-._        _.-'
              `-.__.-'

[1104] 27 Sep 11:14:52.263 # Server started, Redis version 2.8.9
[1104] 27 Sep 11:14:52.310 * DB loaded from disk: 0.047 seconds
[1104] 27 Sep 11:14:52.310 * The server is now ready to accept connections on port 6379

2：配置Redis的jar包和Spring整合redis的jar包。jar包如下。建议使用下面两个版本的jar包。因为其他版本可能会有版本冲突，导致一系列不能使用问题。

<!-- https://mvnrepository.com/artifact/redis.clients/jedis -->
    <dependency>
      <groupId>redis.clients</groupId>
      <artifactId>jedis</artifactId>
      <version>2.7.3</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.springframework.data/spring-data-redis -->
    <dependency>
      <groupId>org.springframework.data</groupId>
      <artifactId>spring-data-redis</artifactId>
      <version>1.6.2.RELEASE</version>
    </dependency>

3：配置redis.properties以及在Spring-bean.xml中做相关配置

redis.properties

redis.host=127.0.0.1
redis.port=6379
redis.password=""
redis.maxIdle=50
redis.maxTotal=100
redis.maxWaitMillis=1000
redis.blockWhenExhausted=true
redis.testOnBorrow=true
redis.timeout=10000
defaultCacheExpireTime=60

spring-bean.xml,如果在本文件中，已经通过<context:property-placeholder location="redis.properties"/>这种方式导入过其他properties文件，那下面文件中这行可以删去。

<?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: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 https://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/aop https://www.springframework.org/schema/aop/spring-aop.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">


<!-- 导入spring-redis配置文件  -->
    <context:property-placeholder location="redis.properties"/>
    <!-- redis数据源  -->
    <bean id="poolConfig" class="redis.clients.jedis.JedisPoolConfig">
        <!-- 最大空闲数 -->
        <property name="maxIdle" value="${redis.maxIdle}" />
        <!-- 最大连接数 -->
        <property name="maxTotal" value="${redis.maxTotal}" />
        <!-- 最大等待时间 -->
        <property name="maxWaitMillis" value="${redis.maxWaitMillis}"/>
        <!-- 连接超时时是否阻塞，false时报异常，true阻塞到直到超时，默认true -->
        <property name="blockWhenExhausted" value="${redis.blockWhenExhausted}"/>
        <!-- 返回连接时，检测连接是否成功 -->
        <property name="testOnBorrow" value="${redis.testOnBorrow}"/>
    </bean>
    <!-- Spring整合Jedis -->
    <bean  id="jedisConnectionFactory" class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory">
        <!-- 指定连接地址 -->
        <property name="hostName" value="127.0.0.1"/>
        <!-- 指定端口号 -->
        <property name="port" value="6379"/>
        <!-- 自定义连接池的配置 -->
        <property name="poolConfig" ref="poolConfig"/>
    </bean>

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

4：使用redis缓存

package com.yc.controller;

import com.yc.po.Hotel;
import com.yc.zip.impl.HotelBizImpl;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.ValueOperations;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import java.util.List;

/**
 * @author Administrator
 */
@Controller
@RequestMapping("/hotel")
public class HotelController {

    @Autowired
    private HotelBizImpl biz;
    /**
     * 自动装配RedisTemplate
     */
    @Autowired
    RedisTemplate redisTemplate = new RedisTemplate();


    @RequestMapping("/finds")
    @ResponseBody
    //查询前最后6条酒店信息
    public List<Hotel> finds() {
        return biz.finds();
    }

    @RequestMapping("/findAll")
    @ResponseBody
    //查看所有酒店信息
    public List<Hotel> findAll() {
        return biz.findAll();
    }


    @RequestMapping("/findByStar")
    @ResponseBody
    //根据星级查询酒店信息
    public List<Hotel> findByStart(String start) {
        int star = Integer.parseInt(start);
        //获取模板中的缓存数据
        ValueOperations<Integer,List> string = redisTemplate.opsForValue();
        //判断缓存中是否有对应的键，若果有就从redis中查询，没有就从数据库中查询，然后设置到redis中
        if (redisTemplate.hasKey(star)){
            System.out.println("从redis中查询");
            return string.get(star);
        }else {
            System.out.println("从数据库中查询");
            string.set(star,biz.findByStart(start));
            return biz.findByStart(start);
        }
    }

}