[Java知识库]SpringBoot与Redis的整合

SpringBoot与Redis的整合

一、导入坐标

 <!--这里与数据库进行了结合所以引入了数据库相关坐标-->
 <!--mysql驱动-->
 <dependency>
     <groupId>mysql</groupId>
     <artifactId>mysql-connector-java</artifactId>
 </dependency>

 <!--mybatis坐标-->
 <dependency>
     <groupId>org.mybatis.spring.boot</groupId>
     <artifactId>mybatis-spring-boot-starter</artifactId>
     <version>2.2.0</version>
 </dependency>

 <dependency>
     <groupId>tk.mybatis</groupId>
     <artifactId>mapper-spring-boot-starter</artifactId>
     <version>2.0.3</version>
 </dependency>
<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>

二、编写application.yaml文件

# 应用名称
spring.application.name=demo1
# 应用服务 WEB 访问端口
server.port=9090

# 指定mapper.xml的位置
mybatis.mapper-locations=classpath*:com/redisdemo/demo1/mapper/xml/*.xml

# 数据库驱动和ip
spring.datasource.driverClassName=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/testredis?serverTimezone=UTC
spring.datasource.username=root
spring.datasource.password=root


# 为某个包目录下，设置日志
logging.level.com.redisdemo=debug

# 表示是否开启 Swagger,一般线上环境是关闭的
spring.swagger2.enable=true

# Redis配置
# Redis数据库索引(默认为0)
spring.redis.database=0
# Redis服务器地址
spring.redis.host=47.107.127.45
# Redis服务器连接端口
spring.redis.port=6379
# Redis服务器连接密码(默认为空)
spring.redis.password=

三、编写测试demo

package com.redisdemo.demo1.controller;

import com.redisdemo.demo1.mapper.UserMapper;
import com.redisdemo.demo1.pojo.User;
import com.redisdemo.demo1.service.UserService;
import com.redisdemo.demo1.vo.UserVo;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.Date;
import java.util.Random;

/**
 * @Description:
 * @Author: ZhongPeng
 * @CreateTime: 2022-01-03  20:19
 */
@RestController
@Api(tags = "用户管理")
@RequestMapping("/user")
public class UserController {

    @Autowired
    private UserService userService;


    @ApiOperation("数据库初始化100条数据")
    @RequestMapping(value = "/init",method = RequestMethod.GET)
    public void init(){
        for (int i = 0; i < 100; i++) {
            Random rand = new Random();
            User user = new User();
            String temp = "un" + i;
            user.setUsername(temp);
            user.setPassword(temp);
            int n = rand.nextInt(2);
            user.setSex(n);
            userService.createUser(user);
        }
    }

    @ApiOperation("单个用户查询，按照userId进行查询")
    @RequestMapping(value = "/findById/{id}",method = RequestMethod.GET)
    public UserVo findById(@PathVariable Integer id){
        User user = userService.findUserById(id);
        UserVo userVo = new UserVo();
        BeanUtils.copyProperties(user,userVo);
        return userVo;
    }

    @ApiOperation("修改某条数据")
    @RequestMapping(value = "/updateUser",method = RequestMethod.POST)
    public void  updateUser(@RequestBody UserVo userVo){
        User user = new User();
        BeanUtils.copyProperties(userVo,user);
        userService.updateUser(user);
    }
}
=================================================
public interface UserService {

    void createUser(User obj);

    void updateUser(User obj);

    User findUserById(Integer userid);

}
=================================================
@Service
public class UserServiceImpl implements UserService {

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

    private static final String CACHE_KEY_USER="user:";

    @Autowired
    private UserMapper userMapper;

    @Autowired
    private RedisTemplate redisTemplate;

    @Override
    public void createUser(User obj) {
        this.userMapper.insert(obj);
        //获取缓存key
        String key=CACHE_KEY_USER+obj.getId();
        //到数据库中，重新获取新数据来做缓存
        User user = this.userMapper.selectByPrimaryKey(obj.getId());
        //opsForValue()代表Redis的String数据结构
        //set代表了redis的SET命令
        redisTemplate.opsForValue().set(key,user);
    }

    @Override
    public void updateUser(User obj) {
        //1.先直接修改数据库
        userMapper.updateByPrimaryKey(obj);
        //2.修改缓存
        User user = userMapper.selectByPrimaryKey(obj.getId());
        //3.获取缓存key
        String key=CACHE_KEY_USER+obj.getId();
        redisTemplate.opsForValue().set(key,user);
    }

    @Override
    public User findUserById(Integer userid) {
        ValueOperations<String,User> valueOperations = redisTemplate.opsForValue();
        User user = valueOperations.get(CACHE_KEY_USER+userid);
        if(Objects.nonNull(user)){
            return user;
        }
        User user1 = userMapper.selectByPrimaryKey(userid);
        String key=CACHE_KEY_USER+user1.getId();
        valueOperations.set(key,user1);
        return user1;
    }
}
==============================================
@ApiModel(value = "用户信息类")
public class UserVo {

    @ApiModelProperty(value = "用户id")
    private Integer id;

    @ApiModelProperty(value = "用户姓名")
    private String username;

    @ApiModelProperty(value = "用户密码")
    private String password;

    @ApiModelProperty(value = "用户性别")
    private Integer sex;

    @ApiModelProperty(value = "是否删除：0：未删除 1：已删除")
    private Integer deleted;

    @ApiModelProperty(value = "更新时间")
    private Date updateTime;

    @ApiModelProperty(value = "创建时间")
    private Date createTime;
    }
=============================================
package com.redisdemo.demo1.pojo;

import javax.persistence.Column;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;
import java.io.Serializable;
import java.util.Date;

/**
 * @Description:User表
 * @Author: ZhongPeng
 * @CreateTime: 2022-01-03  18:44
 */
@Table(name = "users")
public class User implements Serializable {

    private static final Long UUID=1L;

    @Id
    @GeneratedValue(generator = "JDBC")
    private Integer id;

    private String username;

    private String password;

    private Integer sex;

    private Integer deleted;

    @Column(name = "update_time")
    private Date updateTime;

    @Column(name = "create_time")
    private Date createTime;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public Integer getSex() {
        return sex;
    }

    public void setSex(Integer sex) {
        this.sex = sex;
    }

    public Integer getDeleted() {
        return deleted;
    }

    public void setDeleted(Integer deleted) {
        this.deleted = deleted;
    }

    public Date getUpdateTime() {
        return updateTime;
    }

    public void setUpdateTime(Date updateTime) {
        this.updateTime = updateTime;
    }

    public Date getCreateTime() {
        return createTime;
    }

    public void setCreateTime(Date createTime) {
        this.createTime = createTime;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", password='" + password + '\'' +
                ", sex=" + sex +
                ", deleted=" + deleted +
                ", updateTime=" + updateTime +
                ", createTime=" + createTime +
                '}';
    }
}

四、启动后出现的bug

1.由于User类要放到redis缓存中,User类要实现Serializable接口,否则会报错
2.Redis中的配置文件Redis.conf中将这里修改为bind 0.0.0.0,否则会报
java.net.ConnectException: Connection refused: no further information错误
3.在这里注意一点数据库中表字段名字不能叫delete,这个是一个关键字不能当做字段进行使用。