SpringBoot integrated Mybatis usage notes

Today I will sort out the usage notes for SpringBoot integration with Mybatis. Hope it can be helpful to everyone!

  1. Build a SpringBoot basic project.

For details, please refer to SpringBoot: Building the first web program

  1. Introduce related dependencies
<dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.mybatis.spring.boot</groupId><artifactId>mybatis-spring-boot-starter</artifactId><version>2.1.3</version></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.12</version><scope>test</scope></dependency></dependencies>
  1. Prepare the database script

Create a Mysql database, the database is named test, and then execute the script.

/*Navicat MySQL Data TransferSource Server         : 本地MYSQLSource Server Version : 50644Source Host           : localhost:3306Source Database       : testTarget Server Type    : MYSQLTarget Server Version : 50644File Encoding         : 65001Date: 2021-05-16 17:20:26*/SET FOREIGN_KEY_CHECKS=0;-- ------------------------------ Table structure for t_user-- ----------------------------DROP TABLE IF EXISTS `t_user`;CREATE TABLE `t_user` (  `id` int(11) NOT NULL AUTO_INCREMENT,  `user_name` varchar(255) CHARACTER SET armscii8 DEFAULT NULL,  `password` varchar(255) CHARACTER SET armscii8 DEFAULT NULL,  `last_login_time` datetime DEFAULT NULL,  `sex` tinyint(4) DEFAULT NULL,  PRIMARY KEY (`id`)) ENGINE=InnoDB AUTO_INCREMENT=8 DEFAULT CHARSET=utf8;-- ------------------------------ Records of t_user-- ----------------------------INSERT INTO `t_user` VALUES ('1', 'xiaoxin', '123', '2019-07-27 16:01:21', '1');INSERT INTO `t_user` VALUES ('2', 'jack jo', '123', '2019-07-24 16:01:37', '1');INSERT INTO `t_user` VALUES ('4', 'landengdeng', '123', '2019-07-24 16:01:37', '1');INSERT INTO `t_user` VALUES ('5', 'max', '123', '2019-07-24 16:01:37', '1');INSERT INTO `t_user` VALUES ('6', 'liua11', '123456', null, '1');INSERT INTO `t_user` VALUES ('7', 'xiaozhang', '888888', null, '1'); 
  1. Configure the project configuration file application.yml
server:port: 8090mybatis:configuration:map-underscore-to-camel-case: true  mapper-locations: mybatis/**/*Mapper.xmlspring:datasource:driverClassName: com.mysql.cj.jdbc.Driverurl: jdbc:mysql://localhost:3306/test?useSSL=false&useUnicode=true&characterEncoding=utf8username: rootpassword: rootlogging:level:my.springboot.mybatis.dao: debug 
  1. Create entity class UserDO.java
package my.springboot.mybatis.entity;import java.util.Date;public class UserDO {private Integer id;private String userName;private String password;private Integer sex;private Date lastLoginTime;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 Date getLastLoginTime() {return lastLoginTime;    }public void setLastLoginTime(Date lastLoginTime) {this.lastLoginTime = lastLoginTime;    }@Override    public String toString() {return "UserDO{" +"id=" + id +", userName='" + userName + '\'' +", password='" + password + '\'' +", sex=" + sex +", lastLoginTime=" + lastLoginTime +'}';    }} 
  1. Create a mapper file UserInfoMapper.java
package my.springboot.mybatis.dao;import java.util.List;import java.util.Map;import my.springboot.mybatis.entity.UserDO;import org.apache.ibatis.annotations.Mapper;@Mapperpublic interface UserInfoMapper {    UserDO get(Integer id);    List<UserDO> list(Map<String, Object> map);int count(Map<String, Object> map);int save(UserDO user);int update(UserDO user);int remove(Integer id);int batchRemove(Integer[] ids);} 
  1. Create Mapper mapping file UserInfoMapper.xml
<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"><mapper namespace="my.springboot.mybatis.dao.UserInfoMapper"><select id="get" resultType="my.springboot.mybatis.entity.UserDO">      select id,user_name,password,last_login_time,sex from t_user where id = #{value}</select><select id="list" resultType="my.springboot.mybatis.entity.UserDO">        select id,user_name,password,last_login_time,sex from t_user<where><if test="id != null   and id != '-1' " > and id = #{id} </if><if test="userName != null  and userName != '' " > and user_name = #{userName} </if><if test="password != null  and password != '' " > and password = #{password} </if><if test="lastLoginTime != null  and lastLoginTime != '' " > and last_login_time = #{lastLoginTime} </if><if test="sex != null   and sex != '-1' " > and sex = #{sex} </if></where><choose><when test="sort != null and sort.trim() != ''">                order by ${sort} ${order}</when><otherwise>                order by id desc</otherwise></choose><if test="offset != null and limit != null">            limit #{offset}, #{limit}</if></select><select id="count" resultType="int">        select count(*) from t_user<where><if test="id != null   and id != '-1'  " > and id = #{id} </if><if test="userName != null  and userName != ''  " > and user_name = #{userName} </if><if test="password != null  and password != ''  " > and password = #{password} </if><if test="lastLoginTime != null  and lastLoginTime != ''  " > and last_login_time = #{lastLoginTime} </if><if test="sex != null   and sex != '-1'  " > and sex = #{sex} </if></where></select><insert id="save" parameterType="my.springboot.mybatis.entity.UserDO" useGeneratedKeys="true" keyProperty="id">      insert into t_user      (         user_name,         password,         last_login_time,         sex)      values      (         #{userName},         #{password},         #{lastLoginTime},         #{sex})</insert><update id="update" parameterType="my.springboot.mybatis.entity.UserDO">        update t_user<set><if test="userName != null">user_name = #{userName}, </if><if test="password != null">password = #{password}, </if><if test="lastLoginTime != null">last_login_time = #{lastLoginTime}, </if><if test="sex != null">sex = #{sex}</if></set>        where id = #{id}</update><delete id="remove">      delete from t_user where id = #{value}</delete><delete id="batchRemove">        delete from t_user where id in<foreach item="id" collection="array" open="(" separator="," close=")">            #{id}</foreach></delete></mapper>
  1. Create service interface IUserInfoService.java
package my.springboot.mybatis.service;import my.springboot.mybatis.entity.UserDO;import java.util.List;public interface IUserInfoService {    List<UserDO> findAll();    UserDO findById(Integer id);void insert(UserDO model);    Integer update(UserDO model);    Integer deleteById(Integer id);}
  1. Create a service implementation class UserInfoService.java
package my.springboot.mybatis.service.impl; import my.springboot.mybatis.dao.UserInfoMapper;import my.springboot.mybatis.entity.UserDO;import my.springboot.mybatis.service.IUserInfoService;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Service;import java.util.List;@Servicepublic class UserInfoService implements IUserInfoService {@Autowired    private UserInfoMapper mapper;@Override    public List<UserDO> findAll() {return mapper.list(null);    }@Override    public UserDO findById(Integer id) {return mapper.get(id);    }@Override    public void insert(UserDO model) {mapper.save(model);    }@Override    public Integer update(UserDO model) {return  mapper.update(model);    }@Override    public Integer deleteById(Integer id) {return mapper.remove(id);    }} 
  1. Create the controller HomeController.java
package my.springboot.mybatis.controller; import my.springboot.mybatis.entity.UserDO;import my.springboot.mybatis.service.IUserInfoService;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.ResponseBody;import javax.jws.soap.SOAPBinding;import java.util.Date; @Controllerpublic class HomeController {@Autowired    private IUserInfoService userInfoService;@RequestMapping("index") //注解映射请求路径    @ResponseBody //可以将java对象转为json格式的数据    public String index()    {        UserDO user=userInfoService.findById(1);// 新增用户        UserDO add=new UserDO();        add.setSex(1);        add.setUserName("xiaozhang");        add.setPassword("888888");        add.setLastLoginTime(null);//userInfoService.insert(add);        // 更新用户        user.setUserName("xiaoxin");//userInfoService.update(user);        // 删除用户        userInfoService.deleteById(3);return "Hello World !";    }}

Start address: http://localhost:8090/index

  1. Project structure file screenshot