SpringBoot整合MybatisPlus

1、在pom.xml中引入mybatis plus和mysql的jar包

<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/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.jeff</groupId>
     <artifactId>springBoot1</artifactId>
     <version>0.0.1-SNAPSHOT</version>
     <parent>
           <groupId>org.springframework.boot</groupId>
           <artifactId>spring-boot-starter-parent</artifactId>
           <version>2.1.2.RELEASE</version>
     </parent>
     <dependencies>
           <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
           </dependency>
           <!-- mybatis plus依赖包 -->
           <dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatis-plus-boot-starter</artifactId>
                <version>3.1.1</version>
           </dependency>
           <!-- mysql依赖包 -->
           <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
           </dependency>
     </dependencies>
</project>

2、在resources/application.yml配置文件中添加 jdbc和mybatis plus的配置信息

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/jeff
    username: root
    password: root
    driver-class-name: com.mysql.jdbc.Driver
mybatis-plus:
  type-aliases-package: com.jeff.entity
  mapper-locations: classpath:mapper/*.xml
  configuration:
    map-underscore-to-camel-case: false
logging:
  level:
    com.jeff.mapper: DEBUG

3、创建User实体类

package com.jeff.entity;
import java.util.Date;
public class User {
     /**
      * 主键id
      */
     private Integer id;
     /**
      * 登陆名
      */
     private String loginName;
     /**
      * 密码
      */
     private String password;
     /**
      * 加密盐
      */
     private String salt;
     /**
      * 姓名
      */
     private String name;
     /**
      * 昵称
      */
     private String nickName;
     /**
      * 性别:0.男 1.女
      */
     private Integer sex;
     /**
      * 手机号
      */
     private String phone;
     /**
      * 用户状态:
      */
     private String status;
     /**
      * 个人头像
      */
     private String headimgUrl;
     /**
      * 角色id
      */
     private Integer roleId;
     /**
      * 创建时间
      */
     private Date createTime;
     /**
      * 创建人
      */
     private String createName;
     /**
      * 修改时间
      */
     private Date modifyTime;
     /**
      * 修改人
      */
     private String modifyName;

     public Integer getId() {
           return id;
     }
     public void setId(Integer id) {
           this.id = id;
     }
     public String getLoginName() {
           return loginName;
     }
     public void setLoginName(String loginName) {
           this.loginName = loginName;
     }
     public String getPhone() {
           return phone;
     }
     public void setPhone(String phone) {
           this.phone = phone;
     }
     public String getPassword() {
           return password;
     }
     public void setPassword(String password) {
           this.password = password;
     }
     public String getSalt() {
           return salt;
     }
     public void setSalt(String salt) {
           this.salt = salt;
     }
     public String getNickName() {
           return nickName;
     }
     public void setNickName(String nickName) {
           this.nickName = nickName;
     }
     public String getName() {
           return name;
     }
     public void setName(String name) {
           this.name = name;
     }
     public Integer getSex() {
           return sex;
     }
     public void setSex(Integer sex) {
           this.sex = sex;
     }
     public String getHeadimgUrl() {
           return headimgUrl;
     }
     public void setHeadimgUrl(String headimgUrl) {
           this.headimgUrl = headimgUrl;
     }
     public String getStatus() {
           return status;
     }
     public void setStatus(String status) {
           this.status = status;
     }
     public Date getCreateTime() {
           return createTime;
     }
     public void setCreateTime(Date createTime) {
           this.createTime = createTime;
     }
     public Integer getRoleId() {
           return roleId;
     }
     public void setRoleId(Integer roleId) {
           this.roleId = roleId;
     }
     public String getCreateName() {
           return createName;
     }
     public void setCreateName(String createName) {
           this.createName = createName;
     }
     public Date getModifyTime() {
           return modifyTime;
     }
     public void setModifyTime(Date modifyTime) {
           this.modifyTime = modifyTime;
     }
     public String getModifyName() {
           return modifyName;
     }
     public void setModifyName(String modifyName) {
           this.modifyName = modifyName;
     }
}

4、创建UserMapper接口

package com.jeff.mapper;

import org.apache.ibatis.annotations.Mapper;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.jeff.entity.User;

@Mapper
public interface UserMapper extends BaseMapper<User> {

}

5、创建UserService接口

package com.jeff.service;

import com.baomidou.mybatisplus.extension.service.IService;
import com.jeff.entity.User;

public interface UserService extends IService<User> {

}

6、创建UserServiceImpl实现类

package com.jeff.service;

import org.springframework.stereotype.Service;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.jeff.entity.User;
import com.jeff.mapper.UserMapper;

@Service
public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements UserService {

}

7、创建UserController并添加getUserById方法

package com.jeff.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import com.jeff.entity.User;
import com.jeff.service.UserService;

@RestController
public class UserController {

    @Autowired
    private UserService userService;

    @RequestMapping("getUserById")
    public User getUserById(Long id) {

        return userService.getById(id);
    }

}

8、打开浏览器访问getUserById方法