MyBatis查询所有的对象

懂ni

创建dao接口IStudent：

 

package com.ibatis.dao;

 

import java.util.List;
import com.ibatis.model.Student;

public interface IStudentDAO {
 public void addStudent(Student stu);
 public void addStudentBySequence(Student stu);
 public void deleteStudentById(int id);
 public void updateStudent(Student stu);
 public List<Student> queryAllStudents();
 public List<Student> queryStudentsByName(String name);
 public Student queryStudentById(int id);
}

 

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改写Student.xml映射文件：

<?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.ibatis.dao.IStudentDAO">

 

 <select id="selectAllStudents" resultType="Student">
  select * from student
 </select>

 

</mapper>

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创建Ibatis DAO实现类：

 

package com.ibatis.dao.impl;

 

import java.io.IOException;
import java.io.Reader;
import java.util.List;

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 com.ibatis.dao.IStudentDAO;
import com.ibatis.model.Student;

public class IStudentDAOIbatisImpl implements IStudentDAO {

 SqlSession sqlSession = null;
 static SqlSessionFactory sf;
 static{
  Reader reader = null;
  try {
   reader = Resources.getResourceAsReader("com/ibatis/SqlMapConfig.xml");
  } catch (IOException e) {
   e.printStackTrace();
  }
   sf = new SqlSessionFactoryBuilder().build(reader);
 }
 
  public List<Student> queryAllStudents() {
  List<Student> students;
  try{
   sqlSession = sf.openSession();
   students = sqlSession.selectList("selectAllStudents");
  }finally{
   sqlSession.close();
  }
  return students;
 }

 
}
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创建junit测试：

public class IStudentDAOIbatisImplTest {

 @Test
 public void queryAllStudentsTest(){
  IStudentDAO sDAO = new IStudentDAOIbatisImpl();
  List<Student> students = sDAO.queryAllStudents();
  System.out.println(students);
 }

}