SSM+Redis瞎搞

Posted 2020-11-10 谢小文

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之前通过SSM+Jedis勉强入门了，这次搞Redis记录一下关键代码！

初学redis觉定自己搞一个Demo先试试整理一下思路，什么不考虑整，不管对错，试试就试试。

理一下思路，总结一句话：去数据库查数据之前先去redis中读一下，如果没有数据就去数据库查，查到数据后存进redis返回数据。

1、redis.properties写一个方便

##########################
## redis缓存配置
##########################
# redis主机IP
redis.host=192.168.229.128
# redis端口
redis.port=6379
# 链接超时
# redis.timeout=2000
# 密码
# redis.password=root
# 指定redis数据库
# redis.database=2

##########################
## redis连接池配置
##########################
# 最大连接数
redis.maxTotal=30
# 最大空闲连接数
redis.maxIdle=10
# 获取链接最大等待毫秒
redis.maxWaitMillis=1000
# 获取链接时检查有效性
redis.testOnBorrow=true

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2、肯定得配xml文件（applicationContext-Redis.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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

    <!-- redis 数据源 -->
    <bean id="poolConfig" class="redis.clients.jedis.JedisPoolConfig">
        <!-- 定义最大连接数 -->
        <property name="maxTotal" value="${redis.maxTotal}" />
        <!-- 定义最大空闲链接数 -->
        <property name="maxIdle" value="${redis.maxIdle}" />
        <!-- 定义最长等待时间 -->
        <property name="maxWaitMillis" value="${redis.maxWaitMillis}" />
        <!-- 在获取连接时检查是否有效性 -->
        <property name="testOnBorrow" value="${redis.testOnBorrow}" />
    </bean>

    <!-- Spring Data Redis 连接池工厂 -->
    <bean id="jedisConnectionFactory" class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory">
        <!-- redis 主机IP -->
        <property name="hostName" value="${redis.host}" />
        <!-- redis 端口 -->
        <property name="port" value="${redis.port}" />
        <!-- 加载JedisPool配置信息 -->
        <property name="poolConfig" ref="poolConfig" />
    </bean>

    <!-- 配置RedisTemplate API bean -->
    <bean id="redisTemplate" class="org.springframework.data.redis.core.RedisTemplate">
        <!-- Redis hash key: value 序列化 -->
        <property name="hashKeySerializer">
            <bean class="org.springframework.data.redis.serializer.StringRedisSerializer" />
        </property>
        <property name="hashValueSerializer">
            <bean class="org.springframework.data.redis.serializer.StringRedisSerializer" />
        </property>
        <property name="connectionFactory" ref="jedisConnectionFactory" />
    </bean>

</beans>

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3、Controller

package com.xxw.controller;

import com.xxw.pojo.User;
import com.xxw.service.IUserService;
import com.xxw.util.LoggerAspect;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.ModelAndView;

import javax.annotation.Resource;
import java.util.List;

@Controller
@RequestMapping(value = "/user")
public class UserController {

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

    @Resource(name = "UserServiceImplement")
    private IUserService userService;

    @RequestMapping(value = "getUserName", method = RequestMethod.GET)
    @ResponseBody
    public Object getUserName(){
        logger.info("查询用户名");
        try{
            return userService.getUserName();
        }catch (Exception e){
            e.printStackTrace();
        }
        return null;
    }

}

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4、Service接口

package com.xxw.service;

import java.util.List;

public interface IUserService {

    List<String> getUserName() throws Exception;

}

View Code

5、Service实现

package com.xxw.service.impl;

import com.xxw.dao.UserDao;
import com.xxw.service.IUserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Service;

import java.util.List;

@Service(value = "UserServiceImplement")
public class UserServiceImplement implements IUserService {

    @Autowired
    RedisTemplate redisTemplate;
    @Autowired
    UserDao userDao;

    @Override
    public List<String> getUserName() throws Exception {
        String key = "names";  // redis中存储所有用户名的key
        List<String> usernames;    // 存储所有用户名
        // 如果不为空，读取redis中用户名，否则 到数据库取所有用户名存储到redis
        if(redisTemplate.opsForList().size(key) > 0){
            usernames = redisTemplate.opsForList().range(key, 0, -1);
        }else{
            usernames = userDao.findUserNameAll();
            redisTemplate.opsForList().leftPushAll(key, usernames);
        }
        return usernames;
    }

}