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狂神说SpringBoot09：整合MyBatis

 狂神说 SpringBoot 系列连载课程，通俗易懂，基于 SpringBoot2.2.5 版本，欢迎各位狂粉转发关注学习。

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 整合 MyBatis

官方文档：http://mybatis.org/spring-boot-starter/mybatis-spring-boot-autoconfigure/

Maven 仓库地址：https://mvnrepository.com/artifact/org.mybatis.spring.boot/mybatis-spring-boot-starter/2.1.1

 

 整合测试

 1、导入 MyBatis 所需要的依赖

<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.1.1</version>
</dependency>

2、配置数据库连接信息（不变）

spring:
  datasource:
    username: root
    password: 123456
    #?serverTimezone=UTC 解决时区的报错
    url: jdbc:mysql://localhost:3306/springboot?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8
    driver-class-name: com.mysql.cj.jdbc.Driver
    type: com.alibaba.druid.pool.DruidDataSource

#Spring Boot 默认是不注入这些属性值的，需要自己绑定
#druid 数据源专有配置
initialSize: 5
minIdle: 5
maxActive: 20
maxWait: 60000
timeBetweenEvictionRunsMillis: 60000
minEvictableIdleTimeMillis: 300000
validationQuery: SELECT 1 FROM DUAL
testWhileIdle: true
testOnBorrow: false
testOnReturn: false
poolPreparedStatements: true

#配置监控统计拦截的filters，stat:监控统计、log4j：日志记录、wall：防御sql注入
#如果允许时报错  java.lang.ClassNotFoundException: org.apache.log4j.Priority
#则导入 log4j 依赖即可，Maven 地址：https://mvnrepository.com/artifact/log4j/log4j
filters: stat,wall,log4j
maxPoolPreparedStatementPerConnectionSize: 20
useGlobalDataSourceStat: true
connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500</span></pre>

3、测试数据库是否连接成功！

4、创建实体类，导入 Lombok！

Department.java

package com.kuang.pojo;

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


@Data
@NoArgsConstructor
@AllArgsConstructor
public class Department {


</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> Integer id;
</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> String departmentName;



}

5、创建 mapper 目录以及对应的 Mapper 接口

DepartmentMapper.java

//@Mapper : 表示本类是一个 MyBatis 的 Mapper
@Mapper
@Repository
public interface DepartmentMapper {

</span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)"> 获取所有部门信息</span>
List&lt;Department&gt;<span style="color: rgba(0, 0, 0, 1)"> getDepartments();

</span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)"> 通过id获得部门</span>



    Department getDepartment(Integer id);


}

6、对应的 Mapper 映射文件

DepartmentMapper.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="com.kuang.mapper.DepartmentMapper">


<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">select </span><span style="color: rgba(255, 0, 0, 1)">id</span><span style="color: rgba(0, 0, 255, 1)">="getDepartments"</span><span style="color: rgba(255, 0, 0, 1)"> resultType</span><span style="color: rgba(0, 0, 255, 1)">="Department"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span><span style="color: rgba(0, 0, 0, 1)">
   select * from department;
</span><span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">select</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>

<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">select </span><span style="color: rgba(255, 0, 0, 1)">id</span><span style="color: rgba(0, 0, 255, 1)">="getDepartment"</span><span style="color: rgba(255, 0, 0, 1)"> resultType</span><span style="color: rgba(0, 0, 255, 1)">="Department"</span><span style="color: rgba(255, 0, 0, 1)"> parameterType</span><span style="color: rgba(0, 0, 255, 1)">="int"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span><span style="color: rgba(0, 0, 0, 1)">
   select * from department where id = #{id};
</span><span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">select</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>



</mapper>

7、maven 配置资源过滤问题

<resources>
    <resource>
        <directory>src/main/java</directory>
        <includes>
            <include>**/*.xml</include>
        </includes>
        <filtering>true</filtering>
    </resource>
</resources>

8、编写部门的 DepartmentController 进行测试！

@RestController
public class DepartmentController {

@Autowired
DepartmentMapper departmentMapper;

</span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)"> 查询全部部门</span>
@GetMapping("/getDepartments"<span style="color: rgba(0, 0, 0, 1)">)
</span><span style="color: rgba(0, 0, 255, 1)">public</span> List&lt;Department&gt;<span style="color: rgba(0, 0, 0, 1)"> getDepartments(){
    </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> departmentMapper.getDepartments();
}

</span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)"> 查询全部部门</span>
@GetMapping("/getDepartment/{id}"<span style="color: rgba(0, 0, 0, 1)">)
</span><span style="color: rgba(0, 0, 255, 1)">public</span> Department getDepartment(@PathVariable("id"<span style="color: rgba(0, 0, 0, 1)">) Integer id){
    </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> departmentMapper.getDepartment(id);
}



}

启动项目访问进行测试！

我们增加一个员工类再测试下，为之后做准备

1、新建一个 pojo 类 Employee ；

@Data
@AllArgsConstructor
@NoArgsConstructor
public class Employee {

</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> Integer id;
</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> String lastName;
</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> String email;
</span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">1 male, 0 female</span>
<span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> Integer gender;
</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> Integer department;
</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> Date birth;

</span><span style="color: rgba(0, 0, 255, 1)">private</span> Department eDepartment; <span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)"> 冗余设计</span>



}

2、新建一个 EmployeeMapper 接口

//@Mapper : 表示本类是一个 MyBatis 的 Mapper
@Mapper
@Repository
public interface EmployeeMapper {

</span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)"> 获取所有员工信息</span>
List&lt;Employee&gt;<span style="color: rgba(0, 0, 0, 1)"> getEmployees();

</span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)"> 新增一个员工</span>
<span style="color: rgba(0, 0, 255, 1)">int</span><span style="color: rgba(0, 0, 0, 1)"> save(Employee employee);

</span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)"> 通过id获得员工信息</span>



    Employee get(Integer id);


</span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)"> 通过id删除员工</span>
<span style="color: rgba(0, 0, 255, 1)">int</span><span style="color: rgba(0, 0, 0, 1)"> delete(Integer id);



}

3、编写 EmployeeMapper.xml 配置文件

<?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.kuang.mapper.EmployeeMapper">


<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">resultMap </span><span style="color: rgba(255, 0, 0, 1)">id</span><span style="color: rgba(0, 0, 255, 1)">="EmployeeMap"</span><span style="color: rgba(255, 0, 0, 1)"> type</span><span style="color: rgba(0, 0, 255, 1)">="Employee"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">id </span><span style="color: rgba(255, 0, 0, 1)">property</span><span style="color: rgba(0, 0, 255, 1)">="id"</span><span style="color: rgba(255, 0, 0, 1)"> column</span><span style="color: rgba(0, 0, 255, 1)">="eid"</span><span style="color: rgba(0, 0, 255, 1)">/&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">result </span><span style="color: rgba(255, 0, 0, 1)">property</span><span style="color: rgba(0, 0, 255, 1)">="lastName"</span><span style="color: rgba(255, 0, 0, 1)"> column</span><span style="color: rgba(0, 0, 255, 1)">="last_name"</span><span style="color: rgba(0, 0, 255, 1)">/&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">result </span><span style="color: rgba(255, 0, 0, 1)">property</span><span style="color: rgba(0, 0, 255, 1)">="email"</span><span style="color: rgba(255, 0, 0, 1)"> column</span><span style="color: rgba(0, 0, 255, 1)">="email"</span><span style="color: rgba(0, 0, 255, 1)">/&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">result </span><span style="color: rgba(255, 0, 0, 1)">property</span><span style="color: rgba(0, 0, 255, 1)">="gender"</span><span style="color: rgba(255, 0, 0, 1)"> column</span><span style="color: rgba(0, 0, 255, 1)">="gender"</span><span style="color: rgba(0, 0, 255, 1)">/&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">result </span><span style="color: rgba(255, 0, 0, 1)">property</span><span style="color: rgba(0, 0, 255, 1)">="birth"</span><span style="color: rgba(255, 0, 0, 1)"> column</span><span style="color: rgba(0, 0, 255, 1)">="birth"</span><span style="color: rgba(0, 0, 255, 1)">/&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">association </span><span style="color: rgba(255, 0, 0, 1)">property</span><span style="color: rgba(0, 0, 255, 1)">="eDepartment"</span><span style="color: rgba(255, 0, 0, 1)">  javaType</span><span style="color: rgba(0, 0, 255, 1)">="Department"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
        <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">id </span><span style="color: rgba(255, 0, 0, 1)">property</span><span style="color: rgba(0, 0, 255, 1)">="id"</span><span style="color: rgba(255, 0, 0, 1)"> column</span><span style="color: rgba(0, 0, 255, 1)">="did"</span><span style="color: rgba(0, 0, 255, 1)">/&gt;</span>
        <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">result </span><span style="color: rgba(255, 0, 0, 1)">property</span><span style="color: rgba(0, 0, 255, 1)">="departmentName"</span><span style="color: rgba(255, 0, 0, 1)"> column</span><span style="color: rgba(0, 0, 255, 1)">="dname"</span><span style="color: rgba(0, 0, 255, 1)">/&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">association</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">resultMap</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>

<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">select </span><span style="color: rgba(255, 0, 0, 1)">id</span><span style="color: rgba(0, 0, 255, 1)">="getEmployees"</span><span style="color: rgba(255, 0, 0, 1)"> resultMap</span><span style="color: rgba(0, 0, 255, 1)">="EmployeeMap"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span><span style="color: rgba(0, 0, 0, 1)">
    select e.id as eid,last_name,email,gender,birth,d.id as did,d.department_name as dname
    from department d,employee e
    where d.id = e.department
</span><span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">select</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>

<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">insert </span><span style="color: rgba(255, 0, 0, 1)">id</span><span style="color: rgba(0, 0, 255, 1)">="save"</span><span style="color: rgba(255, 0, 0, 1)"> parameterType</span><span style="color: rgba(0, 0, 255, 1)">="Employee"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span><span style="color: rgba(0, 0, 0, 1)">
    insert into employee (last_name,email,gender,department,birth)
    values (#{lastName},#{email},#{gender},#{department},#{birth});
</span><span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">insert</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>

<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">select </span><span style="color: rgba(255, 0, 0, 1)">id</span><span style="color: rgba(0, 0, 255, 1)">="get"</span><span style="color: rgba(255, 0, 0, 1)"> resultType</span><span style="color: rgba(0, 0, 255, 1)">="Employee"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span><span style="color: rgba(0, 0, 0, 1)">
    select * from employee where id = #{id}
</span><span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">select</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>

<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">delete </span><span style="color: rgba(255, 0, 0, 1)">id</span><span style="color: rgba(0, 0, 255, 1)">="delete"</span><span style="color: rgba(255, 0, 0, 1)"> parameterType</span><span style="color: rgba(0, 0, 255, 1)">="int"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span><span style="color: rgba(0, 0, 0, 1)">
    delete from employee where id = #{id}
</span><span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">delete</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>



</mapper>

4、编写 EmployeeController 类进行测试

@RestController
public class EmployeeController {

@Autowired
EmployeeMapper employeeMapper;

</span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)"> 获取所有员工信息</span>
@GetMapping("/getEmployees"<span style="color: rgba(0, 0, 0, 1)">)
</span><span style="color: rgba(0, 0, 255, 1)">public</span> List&lt;Employee&gt;<span style="color: rgba(0, 0, 0, 1)"> getEmployees(){
    </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> employeeMapper.getEmployees();
}

@GetMapping(</span>"/save"<span style="color: rgba(0, 0, 0, 1)">)
</span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">int</span><span style="color: rgba(0, 0, 0, 1)"> save(){
    Employee employee </span>= <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> Employee();
    employee.setLastName(</span>"kuangshen"<span style="color: rgba(0, 0, 0, 1)">);
    employee.setEmail(</span>"qinjiang@qq.com"<span style="color: rgba(0, 0, 0, 1)">);
    employee.setGender(</span>1<span style="color: rgba(0, 0, 0, 1)">);
    employee.setDepartment(</span>101<span style="color: rgba(0, 0, 0, 1)">);
    employee.setBirth(</span><span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> Date());
    </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> employeeMapper.save(employee);
}

</span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)"> 通过id获得员工信息</span>
@GetMapping("/get/{id}"<span style="color: rgba(0, 0, 0, 1)">)
</span><span style="color: rgba(0, 0, 255, 1)">public</span> Employee get(@PathVariable("id"<span style="color: rgba(0, 0, 0, 1)">) Integer id){
    </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> employeeMapper.get(id);
}

</span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)"> 通过id删除员工</span>
@GetMapping("/delete/{id}"<span style="color: rgba(0, 0, 0, 1)">)
</span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">int</span> delete(@PathVariable("id"<span style="color: rgba(0, 0, 0, 1)">) Integer id){
    </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> employeeMapper.delete(id);
}



}

测试结果完成，搞定收工！