spring-boot整合mybatis
阿新 • • 發佈:2021-07-05
官方文件 http://mybatis.org/spring-boot-starter/
mybatis-spring-boot-starter起步依賴提供了整合mybatis的簡便方式
新增maven依賴
<dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>2.2.0</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency>
配置
配置資料庫資訊
spring:
datasource:
username: root
password: root
driver-class-name: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://localhost:3306/test
mybatis中的相關配置
mybatis:
mapper-locations: classpath:com/lyp/mapper/*.xml # mapper對映檔案路徑
type-aliases-package: com.lyp.entity # 實體類支援使用別名
如果使用基於註解的mybatis配置方式,那麼上面的配置不需要。
使用
使用方式與直接使用mybatis一樣
資料庫如下
drop table if exists `employees`; CREATE TABLE `employees` ( `emp_no` int(11) NOT NULL, `birth_date` date NOT NULL, `first_name` varchar(14) NOT NULL, `last_name` varchar(16) NOT NULL, `gender` char(1) NOT NULL, `hire_date` date NOT NULL, PRIMARY KEY (`emp_no`) ); INSERT INTO employees VALUES(10001,'1953-09-02','Georgi','Facello','M','1986-06-26'); INSERT INTO employees VALUES(10002,'1964-06-02','Bezalel','Simmel','F','1985-11-21'); INSERT INTO employees VALUES(10003,'1959-12-03','Parto','Bamford','M','1986-08-28'); INSERT INTO employees VALUES(10004,'1954-05-01','Chirstian','Koblick','M','1986-12-01'); INSERT INTO employees VALUES(10005,'1955-01-21','Kyoichi','Maliniak','M','1989-09-12'); INSERT INTO employees VALUES(10006,'1953-04-20','Anneke','Preusig','F','1989-06-02'); INSERT INTO employees VALUES(10007,'1957-05-23','Tzvetan','Zielinski','F','1989-02-10'); INSERT INTO employees VALUES(10008,'1958-02-19','Saniya','Kalloufi','M','1994-09-15'); INSERT INTO employees VALUES(10009,'1952-04-19','Sumant','Peac','F','1985-02-18'); INSERT INTO employees VALUES(10010,'1963-06-01','Duangkaew','Piveteau','F','1989-08-24'); INSERT INTO employees VALUES(10011,'1953-11-07','Mary','Sluis','F','1990-01-22');
1.定義實體類
com.lyp.entity.Employee
@Data
public class Employee
{
private int number; // 員工編號
private Date birthday; // 出生日期
private String firstName;
private String lastName;
private String gender; // 性別
private Date hireDay; // 僱傭日期
}
1.定義Mapper介面,使用註解@Mapper
標記
com.lyp.mapper.EmployeeMapper
@Mapper
public interface EmployeeMapper
{
List<Employee> findAll();
}
3.配置mapper xml對映檔案
注意:xml對映檔案的路徑要與對應的mapper介面包名對應,同時必須與配置中的
mapper-locations
相同
com/lyp/mapper/EmployeeMapper.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.lyp.mapper.EmployeeMapper">
<select id="findAll" resultType="Employee">
select emp_no number, birth_date birthday, first_name firstName, last_name lastName, gender, hire_date hireDay
from employees;
</select>
</mapper>
對於類欄位名與表列名不一致的情況,除了直接使用別名外,mybatis還可以使用 resultMap
指定轉換規則
<mapper namespace="com.lyp.mapper.EmployeeMapper">
<resultMap id="employeeResultMap" type="employee">
<result property="number" column="emp_no"/>
<result property="birthday" column="birth_date"/>
<result property="firstName" column="first_name"/>
<result property="lastName" column="last_name"/>
<result property="gender" column="gender"/>
<result property="hireDay" column="hire_date"/>
</resultMap>
<select id="findAll" resultMap="employeeResultMap">
select * from employees;
</select>
</mapper>
4.執行crud
com.lyp.controller.MyController
@RestController
public class MyController
{
private final EmployeeMapper employeeMapper;
@Autowired
public MyController(EmployeeMapper employeeMapper)
{
this.employeeMapper = employeeMapper;
}
@GetMapping("/employees")
public Object showAllEmployees()
{
List<Employee> employees = employeeMapper.findAll();
return employees;
}
}