1、首先添加maven引用,javax.xml.bind不添加會報錯 java.lang.ClassNotFoundException: javax.xml.bind.DatatypeConverter
<!-- 持久層mybatis框架 --> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>1.3.2</version> </dependency> <!-- 數據庫驅動程序 --> <dependency> <groupId>com.microsoft.sqlserver</groupId> <artifactId>mssql-jdbc</artifactId> <scope>runtime</scope> </dependency> <dependency> <groupId>javax.xml.bind</groupId> <artifactId>jaxb-api</artifactId> <version>2.3.0</version> </dependency>
2、在resource中添加文件夾mapper,添加xml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.example.demo1.mapper.BusinessMapper"> <resultMap type="com.example.demo1.domain.Business" id="businessResult"> <id property="businessID" column="businessID"/> <result property="loanKind" column="LoanKind"></result> <result property="productType" column="ProductType"></result> <collection property="bills" ofType="com.example.demo1.domain.Bill"> <id property="billID" column="BillID"/> <result property="billMonth" column="BillMonth"/> <result property="billType" column="BillType"/> <result property="billStatus" column="BillStatus"/> </collection> </resultMap> <select id="getBusiness" resultMap="businessResult"> SELECT * FROM dbo.Business b JOIN dbo.Bill bi ON b.BusinessID=bi.BusinessID WHERE b.BusinessID=#{0} </select> <select id="getBusinessOne" resultType="com.example.demo1.domain.Business"> SELECT * FROM dbo.Business WHERE BusinessID=#{0} </select> </mapper>
3、添加package爲domain層,然後添加實體類
package com.example.demo1.domain; import lombok.Data; import java.util.List; @Data public class Business { private int businessID; private String loanKind; private Integer productType; List<Bill> bills; }
package com.example.demo1.domain; import lombok.Data; @Data public class Bill { private int billID; private String billMonth; private int billType; private int billStatus; }
4、添加package爲mapper層,然後添加映射xml的方法
package com.example.demo1.mapper; import com.example.demo1.domain.Business; public interface BusinessMapper { Business getBusinessOne(int id); Business getBusiness(int id); }
5、添加package爲service層,然後添加服務層
package com.example.demo1.service; import com.example.demo1.domain.Business; import com.example.demo1.mapper.BusinessMapper; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; @Service public class BusinessService { @Autowired private BusinessMapper businessMapper; public Business getBusinessOne(int id) { return businessMapper.getBusinessOne(id); } public Business getBusiness(int id) { return businessMapper.getBusiness(id); } }
6、然後添加控制器層
package com.example.demo1.controller; import com.example.demo1.domain.Business; import com.example.demo1.service.BusinessService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RestController; @RestController public class HomeController { @Autowired private BusinessService businessService; @GetMapping("/home/index/{id}") public Business index(@PathVariable("id") int id) { return businessService.getBusinessOne(id); } @GetMapping("/home/bill/{id}") public Business bill(@PathVariable("id") int id) { return businessService.getBusiness(id); } }
7、然後在main函數,也就是啓動類中添加掃描mapper的接口層
package com.example.demo1; import org.mybatis.spring.annotation.MapperScan; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; @SpringBootApplication @MapperScan("com.example.demo1.mapper") public class Demo1Application { public static void main(String[] args) { SpringApplication.run(Demo1Application.class, args); } }
8、application.yml文件中添加數據庫連接配置和mybatis的xml配置
spring: datasource: driver-class-name: com.microsoft.sqlserver.jdbc.SQLServerDriver url: jdbc:sqlserver://192.168.1.1:1433;database=PostLoan; username: sa password: 123456 mybatis: mapper-locations: classpath:mapper/*.xml type-aliases-package: com.example.demo1.domain
項目結構圖
注意事項:
1、resource文件夾中的mapper文件夾中的xml文件的命名空間,就是代碼的mapper層,需要具體到mapper層中的接口,比如在本示例中的xml的命名空間就是下面這樣
<mapper namespace="com.example.demo1.mapper.BusinessMapper">
在代碼的mapper層中有個BusinessMapper的接口,具體到接口名。
2、代碼mapper的接口方法一定要和xml中的id相對應。
3、配置文件中mybatis配置type-aliases-package配置項是指向代碼中的 domain層,但是我發現我指向mapper層也是沒有問題的???
4、如果不想在接口層,也就是mapper層的每個類上添加@Mapper註解,那麼一定要在啓動類上添加@MapperScan註解,來掃描mapper層的所有接口。
以上是基於xml的寫法,還可以基於註解方式來寫sql
package com.example.demo1.mapper; import com.example.demo1.domain.Instruction; import org.apache.ibatis.annotations.Select; public interface IInstruction { @Select("SELECT * FROM pay.DeductInstruction where DeductInstructionID=#{id}") Instruction getInstruction(int id); }
源碼地址:https://github.com/awith/demo1