springboot整合mybatis-plus完整案例

程序员文章站 2022-04-15 19:04:31

1.mybatis-plus，plus意思为插件，只在原来的基础上增强不做改变，只要进行简单的配置就可以对单表进行crud,还提供了强大的条件构造器wrapper以及代码生成器等。如下为springboot整合mybatis-plus的小案例2.要准备的sql语句用来建表create table student(id int(11) primary key auto_increment,sname varchar(36) default null comment'姓名',sno varcha...

1.mybatis-plus，plus意思为插件，只在原来的基础上增强不做改变，只要进行简单的配置就可以对单表进行crud,还提供了强大的条件构造器wrapper以及代码生成器等。如下为springboot整合mybatis-plus的小案例,项目github地址：https://github.com/baisul/springbootmybatisplusDemo.git

2.要准备的sql语句用来建表

create table student(
	id int(11) primary key auto_increment,
	sname varchar(36) default null comment'姓名',
	sno varchar(100) default null comment'学号',
	sex tinyint(2) default null comment'性别,0男，1女',
	hobby varchar(100) default null comment'爱好',
	email varchar(100) default null comment'邮箱'
 )
 
 insert into student values(null,'小明','10001',0,'打篮球','xiaoming@163.com');
 insert into student values(null,'小红','10002',1,'打羽毛球','xiaohong@163.com');
 insert into student values(null,'小白','10003',0,'打篮球','xiaobai@163.com');
 insert into student values(null,'小黑','10004',0,'打保龄球','xiaohei@163.com');
 insert into student values(null,'小胖','10005',0,'打乒乓球','xiaopang@163.com');
 insert into student values(null,'小新','10001',1,'打高尔夫球','xiaoxing@163.com');
 
 create table teacher(
	id int(11) primary key auto_increment,
	tname varchar(36) default null comment'姓名',
	tno varchar(100) default null comment'工号',
	sex tinyint(2) default null comment'性别',
  cource varchar(36) default null comment'教的课程'
 )
 
  insert into teacher values(null,'李小刚','t001',0,'体育');
	insert into teacher values(null,'王春心','t002',1,'语文');
	insert into teacher values(null,'李明','t003',0,'数学');
	insert into teacher values(null,'小黑','t004',0,'物理');

3.新建一个工程，添加依赖
springboot整合mybatis-plus完整案例
pomp.xml

<?xml version="1.0" encoding="UTF-8"?>
<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.5.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.yl</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <!--mybatis-plus依赖-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.3.2</version>
        </dependency>
        <!--代码生成器依赖-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-generator</artifactId>
            <version>3.3.2</version>
        </dependency>
        <!--velocity模板引擎依赖-->
        <dependency>
            <groupId>org.apache.velocity</groupId>
            <artifactId>velocity-engine-core</artifactId>
            <version>2.2</version>
        </dependency>
        <!--freemarker模板引擎依赖-->
        <dependency>
            <groupId>org.freemarker</groupId>
            <artifactId>freemarker</artifactId>
            <version>2.3.30</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.12</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

4.用代码生成相关的实体类，以及mapper,service等，这里用的代码生成器有点问题，id居然没有生成在实体类里，本人手动添加的，关于mybatis-plus代码生成器的更多详细配置可以从这官方文档看更多详细配置
1）项目的结构
springboot整合mybatis-plus完整案例 2）entity

package com.yl.demo.entity;

import java.io.Serializable;

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import lombok.Data;
import lombok.EqualsAndHashCode;

/**
 * <p>
 * 
 * </p>
 *
 * @author wfj
 * @since 2020-11-12
 */
@Data
@EqualsAndHashCode(callSuper = false)
public class Student implements Serializable {

    private static final long serialVersionUID=1L;

    /**
     * id
     */
    @TableId(value="id",type= IdType.AUTO)
    private Integer id;

    /**
     * 姓名
     */
    private String sname;

    /**
     * 学号
     */
    private String sno;

    /**
     * 性别,0男，1女
     */
    private Integer sex;

    /**
     * 爱好
     */
    private String hobby;

    /**
     * 邮箱
     */
    private String email;


}

package com.yl.demo.entity;

import java.io.Serializable;

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import lombok.Data;
import lombok.EqualsAndHashCode;

/**
 * <p>
 * 
 * </p>
 *
 * @author wfj
 * @since 2020-11-12
 */
@Data
@EqualsAndHashCode(callSuper = false)
public class Teacher implements Serializable {

    private static final long serialVersionUID=1L;

    /**
     * id
     */
    @TableId(value="id",type= IdType.AUTO)
    private Integer id;

    /**
     * 姓名
     */
    private String tname;

    /**
     * 工号
     */
    private String tno;

    /**
     * 性别
     */
    private Integer sex;

    /**
     * 教的课程
     */
    private String cource;


}

3）service

package com.yl.demo.service;

import com.yl.demo.entity.Student;
import com.baomidou.mybatisplus.extension.service.IService;

import java.util.List;

/**
 * <p>
 *  服务类
 * </p>
 *
 * @author wfj
 * @since 2020-11-12
 */
public interface IStudentService extends IService<Student> {
    /**
     * 获取学生列表
     * @return
     */
    List<Student> listStudent();

    /**
     * 根据学生ID查找学生
     * @param id
     * @return
     */
    Student getStudentById(Integer id);
}

package com.yl.demo.service;

import com.yl.demo.entity.Teacher;
import com.baomidou.mybatisplus.extension.service.IService;

import java.util.List;

/**
 * <p>
 *  服务类
 * </p>
 *
 * @author wfj
 * @since 2020-11-12
 */
public interface ITeacherService extends IService<Teacher> {

    /**
     * 新增一名老师
     * @param teacher
     * @return
     */
    Integer addTeacher(Teacher teacher);

    /**
     * 获取所有女老师信息
     * @return
     */
    List<Teacher> getTeacherList();
}

4）service.impl

package com.yl.demo.service.impl;

import com.baomidou.mybatisplus.core.conditions.Wrapper;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.yl.demo.entity.Student;
import com.yl.demo.mapper.StudentMapper;
import com.yl.demo.service.IStudentService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

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

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author wfj
 * @since 2020-11-12
 */
@Service
public class StudentServiceImpl extends ServiceImpl<StudentMapper, Student> implements IStudentService {

    @Resource
    private StudentMapper studentMapper;

    /**
     * 这里调的是BaseMapper里的方法，List<T> selectList(@Param("ew") Wrapper<T> queryWrapper);
     * @return
     */
    @Override
    public List<Student> listStudent() {
        return this.studentMapper.selectList(new QueryWrapper<>());
    }

    /**
     * 这里调的是ServiceImpl里面的方法,
     * @param id
     * @return
     */
    @Override
    public Student getStudentById(Integer id) {
        return this.getById(id);
    }
}

package com.yl.demo.service.impl;

import com.baomidou.mybatisplus.core.conditions.Wrapper;
import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.extension.conditions.query.QueryChainWrapper;
import com.yl.demo.entity.Teacher;
import com.yl.demo.mapper.TeacherMapper;
import com.yl.demo.service.ITeacherService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import org.springframework.stereotype.Service;

import java.util.List;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author wfj
 * @since 2020-11-12
 */
@Service
public class TeacherServiceImpl extends ServiceImpl<TeacherMapper, Teacher> implements ITeacherService {

    @Override
    public Integer addTeacher(Teacher teacher) {
        //调用ServiceImpl里的save方法，即可保存一个实体
        return this.save(teacher) == true ? 1 : 0;
    }

    @Override
    public List<Teacher> getTeacherList() {
        //新建一个条件构造器，这个条件构造器就相当于在where后面拼接条件了
        QueryWrapper<Teacher> wrapper = new QueryWrapper<>();
        //设置查询条件字段sex=1的，eq等于，lt小于，gt大于，还有很多可以到官网查看
        wrapper.eq("sex",1);
        List<Teacher> list = this.list(wrapper);
        return list;
    }
}

5）util

package com.yl.demo.util;

import com.baomidou.mybatisplus.extension.api.R;
import lombok.Data;

import java.io.Serializable;

/**
 * 通用结果返回类
 */
@Data
public class Result implements Serializable {
    public int code;
    public String msg;
    public Object data;

   public static Result success() {
       Result result = new Result();
       result.setCode(200);
       result.setMsg("操作成功");
       return result;
   }

    public static Result success(int code,String msg) {
        Result result = new Result();
        result.setCode(code);
        result.setMsg(msg);
        return result;
    }

    public static Result success(int code,String msg,Object data) {
        Result result = new Result();
        result.setCode(code);
        result.setMsg(msg);
        result.setData(data);
        return result;
    }

    public static Result success(Object data) {
        Result result = new Result();
        result.setCode(200);
        result.setMsg("操作成功");
        result.setData(data);
        return result;
    }

    public static Result fail() {
       Result result = new Result();
       result.setCode(0);
       result.setMsg("操作失败");
       return result;
    }

    public static Result fail(int code,String msg) {
        Result result = new Result();
        result.setCode(code);
        result.setMsg(msg);
        return result;
    }

    public static Result fail(int code,String msg,Object data) {
        Result result = new Result();
        result.setCode(code);
        result.setMsg(msg);
        result.setData(data);
        return result;
    }
}

6）controller

package com.yl.demo.controller;


import com.yl.demo.entity.Student;
import com.yl.demo.service.IStudentService;
import com.yl.demo.util.Result;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

/**
 * <p>
 *  前端控制器
 * </p>
 *
 * @author wfj
 * @since 2020-11-12
 */
@RestController
@RequestMapping("/student")
public class StudentController {

    @Autowired
    private IStudentService studentService;

    /**
     * 获取学生列表
     * @return
     */
    @GetMapping("/listStudent")
    public Result listStudent() {
        List<Student> students = studentService.listStudent();
        if (students != null) {
            return Result.success(students);
        } else {
            return Result.fail();
        }
    }

    /**
     * 根据学生ID获取学生
     * @param id
     * @return
     */
    @GetMapping("/getStudentById")
    public Result getStudentById(@RequestParam Integer id) {
        Student student = studentService.getStudentById(id);
        if (student != null) {
            return Result.success(student);
        } else {
            return Result.fail();
        }
    }
}

package com.yl.demo.controller;


import com.yl.demo.entity.Teacher;
import com.yl.demo.service.ITeacherService;
import com.yl.demo.util.Result;
import org.springframework.web.bind.annotation.*;

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

/**
 * <p>
 *  前端控制器
 * </p>
 *
 * @author wfj
 * @since 2020-11-12
 */
@RestController
@RequestMapping("/teacher")
public class TeacherController {

    @Resource
    private ITeacherService teacherService;

    /**
     * 添加老师
     * @param teacher
     * @return
     */
    @PostMapping("/addTeacher")
    public Result addTeacher(@RequestBody Teacher teacher) {
        Integer result = teacherService.addTeacher(teacher);
        if (result > 0) {
            return Result.success();
        } else {
            return Result.fail();
        }
    }

    @GetMapping("/listFemaleTeacher")
    public Result listFemaleTeacher() {
        List<Teacher> teacherList = teacherService.getTeacherList();
        if (teacherList != null) {
            return Result.success(teacherList);
        } else {
            return Result.fail();
        }
    }
}

7）mapper

package com.yl.demo.mapper;

import com.yl.demo.entity.Student;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;

/**
 * <p>
 *  Mapper 接口
 * </p>
 *
 * @author wfj
 * @since 2020-11-12
 */
public interface StudentMapper extends BaseMapper<Student> {

}

package com.yl.demo.mapper;

import com.yl.demo.entity.Teacher;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;

/**
 * <p>
 *  Mapper 接口
 * </p>
 *
 * @author wfj
 * @since 2020-11-12
 */
public interface TeacherMapper extends BaseMapper<Teacher> {

}

8）mapper的xml文件

<?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="com.yl.demo.mapper.StudentMapper">

</mapper>

<?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="com.yl.demo.mapper.TeacherMapper">

</mapper>

9 )application文件

spring.application.name=
#配置端口号以及访问路径
server.port=8080
server.servlet.context-path=/demo

#数据源
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/demo?useUnicode=true&characterEncoding=utf8&useSSL=false&allowPublicKeyRetrieval=true&serverTimezone=Asia/Shanghai
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

#mybatisplus配置
#开启驼峰命名法
mybatis-plus.configuration.map-underscore-to-camel-case=true
#扫描xml文件
mybatis-plus.mapper-locations=classpath:mapper/*.xml

10 )springboot主程序
springboot整合mybatis-plus完整案例 5.用postman来进行接口测试
1)获取学生列表
2）根据学生id获取学生信息

3）添加老师
这里要设置请求头，contentype为application/json