【Redis】三、在springboot中应用redis

一、引入依赖

二、设置redis相关配置

三、准备测试项目框架

四、注册redis中间件

五、实现缓存逻辑

六、查询测试

今天在springboot中学习如何应用redis，实现用户信息管理的缓存中间件实现。

一、引入依赖

redis的客户端主要有Jedis 和 Lettuce两种，Spring Boot 2.x 及以上版本默认使用 Lettuce 作为 Redis 客户端，能提供更好的异步支持，且内置连接池，配置简单，无需额外依赖。

        <dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-redis</artifactId></dependency>

二、设置redis相关配置

在application.yml中配置如下信息。

  redis:host: localhost       # Redis 服务器地址port: 6379            # Redis 服务器端口password: ""          # Redis 密码（若有）database: 0           # 默认使用的数据库索引（0-15）timeout: 5000         # 连接超时时间（毫秒）

三、准备测试项目框架

为了测试springboot应用redis，我们创建一个简单的关于用户管理的模块。包含下面的信息：

sql表

CREATE TABLE users (id INT PRIMARY KEY AUTO_INCREMENT,username VARCHAR(50) NOT NULL UNIQUE,password_hash VARCHAR(255) NOT NULL,full_name VARCHAR(100) NOT NULL,phone_number VARCHAR(20) UNIQUE,email VARCHAR(100) NOT NULL UNIQUE,score_rank INT DEFAULT 0,created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
);

userEntity

package com.naihe.redistest.entity;import com.baomidou.mybatisplus.annotation.*;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.AllArgsConstructor;import java.time.LocalDateTime;@Data
@NoArgsConstructor
@AllArgsConstructor
@TableName("users")
public class UserEntity {@TableId(value = "id", type = IdType.AUTO)private Integer id;private String username;@TableField("password_hash")private String passwordHash;@TableField("full_name")private String fullName;@TableField("phone_number")private String phoneNumber;private String email;@TableField("score_rank")private Integer scoreRank;@TableField(value = "created_at", fill = FieldFill.INSERT)private LocalDateTime createdAt;@TableField(value = "updated_at", fill = FieldFill.UPDATE)private LocalDateTime updatedAt;
}

controller

package com.naihe.redistest.controller;import com.naihe.redistest.pojo.dto.RegisterDTO;
import com.naihe.redistest.service.UserService;
import com.naihe.redistest.utils.Result;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;import javax.servlet.http.HttpServletRequest;
import java.security.NoSuchAlgorithmException;@Slf4j
@Component
@Controller
@RestController
@RequestMapping("/user")
public class UserController {@AutowiredUserService userService;/*** 用户注册接口，接收用户注册信息并处理** @param registerBean 用户注册信息的传输对象* @return Result 返回操作结果*/@PostMapping("/register")public Result register(@RequestBody RegisterDTO registerBean){userService.insertUser(registerBean);return Result.ok().data("msg", "注册成功");}/*** 查询用户分数** @param userId 用户的id* @return Result 返回操作结果*/@GetMapping("/getScore/{userId}")public Result getScore(@PathVariable String userId) {Integer score = userService.getScore(userId);return Result.ok().data("score", score);}}

service

package com.naihe.redistest.service.impl;import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.naihe.redistest.entity.UserEntity;
import com.naihe.redistest.mapper.UserMapper;
import com.naihe.redistest.pojo.dto.RegisterDTO;
import com.naihe.redistest.service.UserService;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Service;import java.util.concurrent.TimeUnit;@Service
public class UserServiceImpl implements UserService {@Autowiredprivate UserMapper userMapper;@Autowiredprivate RedisTemplate<String, Object> redisTemplate;private static final String USER_SCORE_KEY = "user:score:";private static final long CACHE_EXPIRE_TIME = 30; // 缓存30分钟@Overridepublic void insertUser(RegisterDTO registerBean) {if (userMapper.selectOne(new QueryWrapper<UserEntity>().eq("username", registerBean.getUsername())) != null) {throw new RuntimeException(registerBean.getUsername() + "已存在");}UserEntity userEntity = new UserEntity();BeanUtils.copyProperties(registerBean,userEntity);userMapper.insert(userEntity);}
}

添加测试数据

四、注册redis中间件

package com.naihe.redistest.config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;@Configuration
public class RedisConfig {@Beanpublic RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) {RedisTemplate<String, Object> template = new RedisTemplate<>();template.setConnectionFactory(factory);// 设置 key 的序列化方式template.setKeySerializer(new StringRedisSerializer());// 设置 value 的序列化方式（JSON 格式）template.setValueSerializer(new GenericJackson2JsonRedisSerializer());// 设置 hash key 和 value 的序列化方式template.setHashKeySerializer(new StringRedisSerializer());template.setHashValueSerializer(new GenericJackson2JsonRedisSerializer());template.afterPropertiesSet();return template;}
}

五、实现缓存逻辑

在service服务层中应用，查询用户分数时，优先从redis中查找，若不存在，则从mysql数据库中查找后，添加到redis中。

package com.naihe.redistest.service.impl;import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.naihe.redistest.entity.UserEntity;
import com.naihe.redistest.mapper.UserMapper;
import com.naihe.redistest.pojo.dto.RegisterDTO;
import com.naihe.redistest.service.UserService;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Service;import java.util.concurrent.TimeUnit;@Service
public class UserServiceImpl implements UserService {@Autowiredprivate UserMapper userMapper;@Autowiredprivate RedisTemplate<String, Object> redisTemplate;private static final String USER_SCORE_KEY = "user:score:";private static final long CACHE_EXPIRE_TIME = 30; // 缓存30分钟@Overridepublic void insertUser(RegisterDTO registerBean) {if (userMapper.selectOne(new QueryWrapper<UserEntity>().eq("username", registerBean.getUsername())) != null) {throw new RuntimeException(registerBean.getUsername() + "已存在");}UserEntity userEntity = new UserEntity();BeanUtils.copyProperties(registerBean,userEntity);userMapper.insert(userEntity);}public Integer getScore(String userId) {String key = USER_SCORE_KEY + userId;// 先从Redis获取缓存数据Integer score = (Integer) redisTemplate.opsForValue().get(key);if (score != null) {return score;}// 缓存未命中，从数据库获取UserEntity user = userMapper.selectById(userId);if (user == null) {throw new RuntimeException("用户不存在");}score = user.getScoreRank();// 将数据存入Redis缓存redisTemplate.opsForValue().set(key, score, CACHE_EXPIRE_TIME, TimeUnit.MINUTES);return score;}
}