有手就行的SpringBoot整合MyBatis

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这篇博客详细介绍了如何通过SpringBoot整合MyBatis框架，包括创建MySQL数据库表、配置SpringBoot项目、添加依赖、创建实体类、Mapper和Service层，以及Controller层的实现，最终实现对雇员和部门表的CRUD操作。

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今天了解了通过SpringBoot整合MyBatis的框架自己写一个博客复习一波

任务：创建两张表:

员工表(员工姓名, 员工的年龄, 员工性别, 部门id, id , 创建时间, 更新时间)

部门表(id, 创建时间, 更新时间, 部门名称)

执行每张表的CRUD

自定义关联表查询 自定义业务场景

思路：首先通过mysql数据库创建两张表

CREATE DATABASE ead;
CREATE TABLE employees (
  id INT(10) PRIMARY KEY AUTO_INCREMENT,
  empName VARCHAR(50),
  empAge INT(10),
  empSex VARCHAR(10),
  depId INT(10),
  createBy DATE,
  updateBy DATE
);

CREATE TABLE departments (
  id INT(10) PRIMARY KEY AUTO_INCREMENT,
  depName VARCHAR(50),
  createBy DATE,
  updateBy DATE
);

INSERT INTO employees(id,empName,empAge,empSex,depId,createBy,updateBy) VALUES(1001,'李白',18,'男',1,NOW(),NULL);
SELECT * FROM employees;

INSERT INTO departments(id,depName,createBy,updateBy) VALUES(1,'刺客',NOW(),NULL);
SELECT * FROM departments;

创建一个数据库名为：ead 分别创建两张表雇员和部门并为两张表各插入一条语句（执行该代码后，查询出的结果表如下）

雇员表

id	empName	empAge	createBy	empSex	depId	updateBy
1001	李白	18	2020-08-18	男	1	(null)

部门表

id	depName	createBy	updateBy
1	刺客	2020-08-18	(NULL)

表创建完成之后，打开idea创建一个SpringBoot开始整合MyBatis

在这里插入图片描述

进入idea选择Spring Initializr 点击下一步（Next）

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输入自己的group和Artifact Java版本选择8或者以上点击下一步

在这里插入图片描述

选择这两个依赖点击下一步，其他依赖可以直接进入后在pom文件中导入

在这里插入图片描述

直接点击finish 进入idea

在这里插入图片描述

进入后页面如下，我们需要整合mybatis框架，需要Mybatis和Mysql的jar包

我们在pom.xml文件的dependencys中添加以下两个依赖

<dependency>
			<groupId>org.mybatis.spring.boot</groupId>
			<artifactId>mybatis-spring-boot-starter</artifactId>
			<version>1.3.2</version>
		</dependency>
 
		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<scope>runtime</scope>
		</dependency>

依赖添加完成我们在项目的src/main/java/com/pzy/ead下：我们通过数据库表分别创建出每张表的 [实体类(entity)，数据访问层(dao|mapper)，业务逻辑层(Service)，控制层(Controller)]

创建完成后表结构如下

在这里插入图片描述

在实体类表中根据数据库表字段创建字段信息

employees表实体类

package com.pzy.ead.entity;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.util.Date;
@Data
@AllArgsConstructor
@NoArgsConstructor
public class Employees {
    private Integer id;
    private String empName;
    private Integer empAge;
    private String empSex;
    private Integer depId;
    private Date createBy;
    private Date updateBy;
}

Departments表实体类

package com.pzy.ead.entity;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.util.Date;

@Data
@NoArgsConstructor
@AllArgsConstructor
public class Departments {
    private Integer id;
    private String depName;
    private Date createBy;
    private Date updateBy;
}

创建实体类使用了lombok依赖

通过注解实现set，get方法以及无参构造和有参构造，减少了代码的构成

注:使用lombok时，需要先下载它的插件，否则可能无法使用

实体类创建完成后，打开resources文件将application.propeties删除，我们使用application.yml文件进行springboot的配置（配置mybatis和数据源）

在这里插入图片描述

分别在application.yml和application-dev.yml中添加如下代码

application.yml

spring:
  profiles:
    active: dev

application-dev.yml

server:
  port: 9000

spring:
  datasource:
    username: pzy
    password: 123
    url: jdbc:mysql://localhost:3306/ead?useUnicode=true&characterEncoding=utf-8&useSSL=true&serverTimezone=UTC
    driver-class-name: com.mysql.cj.jdbc.Driver

mybatis:
  mapper-locations: classpath:mapper/*Mapper.xml
  type-aliases-package: com.pzy.ead.entity

创建完成两个yml文件后我们根据application-dev的mybatis配置的mapper路径中创建两张数据库表的Mapper.xml文件

在这里插入图片描述

创建后在他们的命名空间中添加他们各自映射的Mapper的java文件路径,并分别写入一个查询语句测试一下

EmployeesMapper.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "mybatis-3-mapper.dtd">
<mapper namespace="com.pzy.ead.mapper.EmployeesMapper">
    <select id="selectAllEmployees" resultType="Employees">
        SELECT id,empName,empAge,empSex,depId,createBy,updateBy FROM employees;
    </select>
</mapper>

DepartmentMapper.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "mybatis-3-mapper.dtd">
<mapper namespace="com.pzy.ead.mapper.DepartmentsMapper">
    <select id="selectAllDepartments" resultType="Departments">
        SELECT id,depName,createBy,updateBy FROM departments;
    </select>
</mapper>

创建文件后我们在他们各自的Mapper的java文件中创建出这两个方法并通过注解层层映射出来

DepartmentsMapper内代码

package com.pzy.ead.mapper;

import com.pzy.ead.entity.Departments;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;

import java.util.List;
@Repository
@Mapper
public interface DepartmentsMapper {
    List<Departments> selectAllDepartments();
}

EmployeesMapper内代码

package com.pzy.ead.mapper;

import com.pzy.ead.entity.Employees;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;

import java.util.List;
@Repository
@Mapper
public interface EmployeesMapper {
    List<Employees> selectAllEmployees();
}

在Mapper层中分别给两个接口方法名称与Mapper.xml文件处的一致

并添加注解使Service层能够自动创建此类

Service层

DepartmentsService

package com.pzy.ead.service;

import com.pzy.ead.entity.Departments;
import com.pzy.ead.mapper.DepartmentsMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;
@Service
public class DepartmentsService {
    @Autowired
    DepartmentsMapper departmentsMapper;
    public List<Departments> findAllDepartments(){
        return departmentsMapper.selectAllDepartments();
    }
}

EmployeesService

package com.pzy.ead.service;

import com.pzy.ead.entity.Employees;
import com.pzy.ead.mapper.EmployeesMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;
@Service
public class EmployeesService {
    @Autowired
    EmployeesMapper employeesMapper;
    public List<Employees> findAllEmployees(){
        return employeesMapper.selectAllEmployees();
    }
}

在Service中使用Autowired自动导入他们各自的Mapper对象，并在Service中添加注解Service以便于他们的控制器层的调用

控制层

DepartmentsController

package com.pzy.ead.controller;

import com.pzy.ead.entity.Departments;
import com.pzy.ead.service.DepartmentsService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
public class DepartmentsController {
    @Autowired
    private DepartmentsService departmentsService;

    @RequestMapping("/findDep")
    public List<Departments> findAll(){
        return departmentsService.findAllDepartments();
    }
}

EmployeesController

package com.pzy.ead.controller;

import com.pzy.ead.entity.Employees;
import com.pzy.ead.service.EmployeesService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
public class EmployeesController {
    @Autowired
    private EmployeesService employeesService;
    @RequestMapping("/findEmp")
    public List<Employees> findAll(){
        return employeesService.findAllEmployees();
    }
}

最后在我们的项目启动处添加一个Mapper的扫描

@MapperScan(“com.pzy.ead.mapper”) 括号内是我们的Mapper包的路径表示直接扫描我们的Mapper包内的所有接口并与Mapper.xml文件进行绑定

package com.pzy.ead;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@MapperScan("com.pzy.ead.mapper")
public class EadApplication {

    public static void main(String[] args) {
        SpringApplication.run(EadApplication.class, args);
    }

}

运行项目测试是否成功：

在这里插入图片描述
项目运行，通过我们设置的9000端口号与我们在控制器中设置的RequestMapping内的路径查询

测试成功返回了我们需要的List集合格式

按照格式创建出两张表的CRUD

Mapper

DepartmentsMapper

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "mybatis-3-mapper.dtd">
<mapper namespace="com.pzy.ead.mapper.DepartmentsMapper">
    <select id="selectAllDepartments" resultType="Departments">
        SELECT id,depName,createBy,updateBy FROM departments;
    </select>
    <select id="selectDepartments" resultType="Departments">
        SELECT id,depName,createBy,updateBy FROM departments WHERE id = #{id};
    </select>
    <insert id="insertDepartments" parameterType="Departments">
        INSERT INTO departments(depName,createBy) VALUES(#{depName},now());
    </insert>
    <delete id="deleteDepartments">
        DELETE FROM departments WHERE id = #{id}
    </delete>
    <update id="updateDepartments" parameterType="Departments">
        UPDATE departments
        <set>
            <if test="depName!=null and depName!=''">
                depName = #{depName},
            </if>
                updateBy = now()
        </set>
        WHERE id = #{id}
    </update>
</mapper>

EmployeesMapper

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "mybatis-3-mapper.dtd">
<mapper namespace="com.pzy.ead.mapper.EmployeesMapper">
    <select id="selectAllEmployees" resultType="Employees">
        SELECT id,empName,empAge,empSex,depId,createBy,updateBy FROM employees;
    </select>
    <select id="selectEmployees" resultType="Employees">
        SELECT id,empName,empAge,empSex,depId,createBy,updateBy FROM employees WHERE id = #{id};
    </select>
    <insert id="insertEmployees" parameterType="Employees">
        INSERT INTO employees(empName,empAge,empSex,depId,createBy) VALUES(#{empName},#{empAge},#{empSex},#{depId},now());
    </insert>
    <delete id="deleteEmployees">
        DELETE FROM employees WHERE id = #{id}
    </delete>
    <update id="updateEmployees" parameterType="Employees">
        UPDATE employees
        <set>
            <if test="empName!=null and empName!=''">
                empName = #{empName},
            </if>
            <if test="empAge!=null">
                empAge = #{empAge},
            </if>
            <if test="empSex!=null and empSex!=''">
                empSex = #{empSex},
            </if>
            <if test="depId!=null">
                depId = #{depId},
            </if>
                updateBy = now()
        </set>
        where id = #{id}
    </update>
</mapper>

Mapper Java代码

DepartmentsMapper

package com.pzy.ead.mapper;

import com.pzy.ead.entity.Departments;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import org.springframework.stereotype.Repository;

import java.util.List;
@Repository
@Mapper
public interface DepartmentsMapper {
    List<Departments> selectAllDepartments();
    Departments selectDepartments(@Param("id") Integer id);
    Integer insertDepartments(Departments emp);
    Integer deleteDepartments(@Param("id") Integer id);
    Integer updateDepartments(Departments emp);
}

EmployeesMapper

package com.pzy.ead.mapper;

import com.pzy.ead.entity.Employees;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import org.springframework.stereotype.Repository;

import java.util.List;
@Repository
@Mapper
public interface EmployeesMapper {
    List<Employees> selectAllEmployees();
    Employees selectEmployees(@Param("id") Integer id);
    Integer insertEmployees(Employees emp);
    Integer deleteEmployees(@Param("id") Integer id);
    Integer updateEmployees(Employees emp);
}

Service

DepartmentsService

package com.pzy.ead.service;

import com.pzy.ead.entity.Departments;
import com.pzy.ead.mapper.DepartmentsMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;
@Service
public class DepartmentsService {
    @Autowired
    DepartmentsMapper departmentsMapper;
    public List<Departments> findAllDepartments(){
        return departmentsMapper.selectAllDepartments();
    }
    public Departments findDepartments(Integer id){
        return departmentsMapper.selectDepartments(id);
    }
    public Integer addDepartments(Departments emp){
        return departmentsMapper.insertDepartments(emp);
    }

    public Integer removeDepartments(Integer id){
        return departmentsMapper.deleteDepartments(id);
    }

    public Integer modifyDepartments(Departments emp){
        return departmentsMapper.updateDepartments(emp);
    }
}

EmployeesService

package com.pzy.ead.service;

import com.pzy.ead.entity.Employees;
import com.pzy.ead.mapper.EmployeesMapper;
import org.apache.ibatis.annotations.Param;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;
@Service
public class EmployeesService {
    @Autowired
    EmployeesMapper employeesMapper;
    public List<Employees> findAllEmployees(){
        return employeesMapper.selectAllEmployees();
    }
    public Employees findEmployees(Integer id){
        return employeesMapper.selectEmployees(id);
    }
    public Integer addEmployees(Employees emp){
        return employeesMapper.insertEmployees(emp);
    }

    public Integer removeEmployees(Integer id){
        return employeesMapper.deleteEmployees(id);
    }

    public Integer modifyEmployees(Employees emp){
        return employeesMapper.updateEmployees(emp);
    }

}

控制层Controller

DepartmentsController

package com.pzy.ead.controller;

import com.pzy.ead.entity.Departments;
import com.pzy.ead.service.DepartmentsService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
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;

@RestController
public class DepartmentsController {
    @Autowired
    private DepartmentsService departmentsService;
    @RequestMapping("/findDep")
    public List<Departments> findAll(){
        return departmentsService.findAllDepartments();
    }
    @RequestMapping("/findDep/{id}")
    public Departments findEmp(@PathVariable Integer id){
        return departmentsService.findDepartments(id);
    }
    @RequestMapping("/addDep")
    public Integer createEmp(@RequestParam("depName") String depName){
        Departments dep = new Departments();
        dep.setDepName(depName);
        return departmentsService.addDepartments(dep);
    }
    @RequestMapping("/modifyDep")
    public Integer modifyEmp(@RequestParam(value = "depName",required = false) String depName,@RequestParam("id") Integer id){
        Departments dep = new Departments();
        dep.setId(id);
        if(depName!=null) {
            dep.setDepName(depName);
        }
        return departmentsService.modifyDepartments(dep);
    }
    @RequestMapping("/deleteDep/{id}")
    public Integer removeEmp(@PathVariable Integer id){
        return departmentsService.removeDepartments(id);
    }
}

EmployeesController

package com.pzy.ead.controller;

import com.pzy.ead.entity.Employees;
import com.pzy.ead.service.EmployeesService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
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;

@RestController
public class EmployeesController {
    @Autowired
    private EmployeesService employeesService;
    @RequestMapping("/findEmp")
    public List<Employees> findAll(){
        return employeesService.findAllEmployees();
    }
    @RequestMapping("/findEmp/{id}")
    public Employees findEmp(@PathVariable Integer id){
        return employeesService.findEmployees(id);
    }
    @RequestMapping("/addEmp")
    public Integer createEmp(@RequestParam("depId") Integer depId,
                             @RequestParam("empAge") Integer empAge,
                             @RequestParam("empName") String empName,
                             @RequestParam("empSex") String empSex){
        Employees emp = new Employees();
        emp.setDepId(depId);
        emp.setEmpAge(empAge);
        emp.setEmpName(empName);
        emp.setEmpSex(empSex);
        return employeesService.addEmployees(emp);
    }


    @RequestMapping("/modifyEmp/{id}")
    public Integer modifyEmp1(@RequestParam(value = "depId",required = false) Integer depId,
                              @RequestParam(value = "empAge",required = false) Integer empAge,
                              @RequestParam(value = "empName",required = false) String empName,
                              @RequestParam(value = "empSex",required = false) String empSex,
                              @PathVariable("id") Integer id){
        Employees emp = new Employees();
        emp.setId(id);
        emp.setDepId(depId);
        emp.setEmpAge(empAge);
        emp.setEmpName(empName);
        emp.setEmpSex(empSex);
        return employeesService.modifyEmployees(emp);
    }


    @RequestMapping("/deleteEmp/{id}")
    public Integer removeEmp(@PathVariable Integer id){
        return employeesService.removeEmployees(id);
    }
}