关于Mybatis的sql注释问题解析

//mapper下的sql注释
package com.msb.mapper;
import com.msb.pojo.Dept;
import com.msb.pojo.Emp;
import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;
import java.awt.*;
public interface EmpTestMapper {
    @Select("select * from dept where deptno =#{deptno}")
    Dept findByDeptno(int deptno);
    @Update("update dept set dname =#{dname}, loc =#{loc} where deptno =#{deptno}")
    int updateDept(Dept dept);
    @Insert("insert into dept values(DEFAULT,#{dname},#{loc})")
    int addDept(Dept dept);
    @Delete("delete from dept where deptno =#{deptno}")
    int removeDept(int deptno);
}

import com.msb.mapper.DeptMapper;
import com.msb.mapper.EmpMapper;
import com.msb.mapper.EmpTestMapper;
import com.msb.pojo.Dept;
import com.msb.pojo.Emp;
import com.msb.pojo.Projectrecord;
import com.msb.pojo.Projects;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import java.io.IOException;
import java.io.InputStream;
import java.util.Date;
import java.util.List;

public class Test1 {
    SqlSession sqlSession = null;
    EmpMapper mapper =null;
   @Before
   public void test1(){
       //首先做一个对象SqlSessionFactoryBuilder建立一个绘话
       SqlSessionFactoryBuilder ssfb = new SqlSessionFactoryBuilder();
       //有一个文本输入的io流进行读取操作
       InputStream stream = null;
       try {
           //这里的路径直接会定位到配置文件classes下面；所以这个文件在次目录下--编译和
           //-图纸；对数据库文件进行读取，获取一个io流，由于配置文件在classes下面，直接写文件名即可
           stream = Resources.getResourceAsStream("sqlMapConfig.xml");
       } catch (IOException e) {
           e.printStackTrace();
       }
       //build需要指向一个文件进行读取出来--工厂
       SqlSessionFactory factory = ssfb.build(stream);
        //需要用sqlSession去调用增删改查--工人去获取数据，打开这个绘话
       sqlSession = factory.openSession(true);
   }

    @Test
    public void test4(){
        EmpTestMapper mapper = sqlSession.getMapper(EmpTestMapper.class);
        Dept emp = mapper.findByDeptno(20);
        Dept dept = new Dept();
        dept.setDeptno(null);
        dept.setLoc("大格");
        dept.setDname("水军");
        int addDept = mapper.addDept(dept);
        System.out.println(addDept);
        System.out.println(emp);
    }

    @After
    public void test3(){
       if (sqlSession!=null){
           sqlSession.close();
       }
    }
}