一、创建接口
创建一个接口文件:
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| package com.glemontree.mybatis.dao; import com.glemontree.mybatis.bean.Employee; public interface EmployeeMapper { public Employee getEmpById(Integer id); }
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这个接口可以与SQL映射文件进行动态绑定,此时需要对SQL映射文件进行一些修改,如下:
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| <?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.glemontree.mybatis.dao.EmployeeMapper"> namespace:名称空间;指定为接口的全类名 id:唯一标识 resultType:返回值类型 #{id}:从传递过来的参数中取出id值 public Employee getEmpById(Integer id); --> <select id="getEmpById" resultType="com.glemontree.mybatis.bean.Employee"> select * from tbl_employee where id = #{id} </select> </mapper>
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所进行的修改主要有:
- 修改namespace为接口的全类名
- 修改
<select>
标签的id属性为接口中方法的名字
二、测试
测试代码如下:
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| @Test public void test01() throws IOException { SqlSessionFactory sqlSessionFactory = getSqlSessionFactory(); SqlSession openSession = sqlSessionFactory.openSession(); try { EmployeeMapper mapper = openSession.getMapper(EmployeeMapper.class); Employee employee = mapper.getEmpById(1); System.out.println(employee); } finally { openSession.close(); } }
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