狂神说SpringBoot09：整合MyBatis
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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
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("qinjiang@qq.com"); 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！
