整合MyBatis 9

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

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 { private Integer id; private 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 { // 获取所有部门信息 List<Department> getDepartments(); // 通过id获得部门  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"> <select id="getDepartments" resultType="Department"> select * from department; </select> <select id="getDepartment" resultType="Department" parameterType="int"> select * from department where id = #{id}; </select> </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;
    
    // 查询全部部门 @GetMapping("/getDepartments") public List<Department> getDepartments(){ return departmentMapper.getDepartments(); } // 查询全部部门 @GetMapping("/getDepartment/{id}") public Department getDepartment(@PathVariable("id") Integer id){ return 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 {

    private Integer id; private String lastName; private String email; //1 male, 0 female private Integer gender; private Integer department; private Date birth; private Department eDepartment; // 冗余设计  }

2、新建一个 EmployeeMapper 接口

//@Mapper : 表示本类是一个 MyBatis 的 Mapper
@Mapper
@Repository
public interface EmployeeMapper { // 获取所有员工信息 List<Employee> getEmployees(); // 新增一个员工 int save(Employee employee); // 通过id获得员工信息  Employee get(Integer id); // 通过id删除员工 int 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"> <resultMap id="EmployeeMap" type="Employee"> <id property="id" column="eid"/> <result property="lastName" column="last_name"/> <result property="email" column="email"/> <result property="gender" column="gender"/> <result property="birth" column="birth"/> <association property="eDepartment" javaType="Department"> <id property="id" column="did"/> <result property="departmentName" column="dname"/> </association> </resultMap> <select id="getEmployees" resultMap="EmployeeMap"> 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 </select> <insert id="save" parameterType="Employee"> insert into employee (last_name,email,gender,department,birth) values (#{lastName},#{email},#{gender},#{department},#{birth}); </insert> <select id="get" resultType="Employee"> select * from employee where id = #{id} </select> <delete id="delete" parameterType="int"> delete from employee where id = #{id} </delete> </mapper>

4、编写EmployeeController类进行测试

@RestController
public class EmployeeController {

    @Autowired
    EmployeeMapper employeeMapper;

    // 获取所有员工信息 @GetMapping("/getEmployees") public List<Employee> getEmployees(){ return employeeMapper.getEmployees(); } @GetMapping("/save") public int save(){ Employee employee = new Employee(); employee.setLastName("kuangshen"); employee.setEmail("[email protected]"); employee.setGender(1); employee.setDepartment(101); employee.setBirth(new Date()); return employeeMapper.save(employee); } // 通过id获得员工信息 @GetMapping("/get/{id}") public Employee get(@PathVariable("id") Integer id){ return employeeMapper.get(id); } // 通过id删除员工 @GetMapping("/delete/{id}") public int delete(@PathVariable("id") Integer id){ return employeeMapper.delete(id); } }

测试结果完成，搞定收工！