mybatis 详解（三）------入门实例（基于注解）

package com.ys.annocation;

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 com.ys.po.User;

public interface UserMapper {
	//根据 id 查询 user 表数据
	@Select("select * from user where id = #{id}")
	public User selectUserById(int id) throws Exception;

	//向 user 表插入一条数据
	@Insert("insert into user(username,sex,birthday,address) value(#{username},#{sex},#{birthday},#{address})")
	public void insertUser(User user) throws Exception;
	
	//根据 id 修改 user 表数据
	@Update("update user set username=#{username},sex=#{sex} where id=#{id}")
	public void updateUserById(User user) throws Exception;
	
	//根据 id 删除 user 表数据
	@Delete("delete from user where id=#{id}")
	public void deleteUserById(int id) throws Exception;
	
}

  <mappers>
         <mapper class="com.ys.annocation.UserMapper"/>
  </mappers>

package com.ys.test;

import java.io.InputStream;

import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Before;
import org.junit.Test;

import com.ys.annocation.UserMapper;
import com.ys.po.User;

public class UserAnnocationTest {
	//定义 SqlSession
	SqlSession session =null;
	
	@Before
	public void init(){
		//定义mybatis全局配置文件
		String resource = "mybatis-configuration.xml";
		//加载 mybatis 全局配置文件
		InputStream inputStream = CRUDTest.class.getClassLoader()
									.getResourceAsStream(resource);
		//构建sqlSession的工厂
		SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
		//根据 sqlSessionFactory 产生 session
		session = sessionFactory.openSession();
	}
	
	//注解的增删改查方法测试
	@Test
	public void testAnncationCRUD() throws Exception{
		//根据session获取 UserMapper接口
		UserMapper userMapper = session.getMapper(UserMapper.class);
		//调用selectUserById()方法
		User user = userMapper.selectUserById(1);
		System.out.println(user);
		
		//调用  insertUser() 方法
		User user1 = new User();
		user1.setUsername("aliks");
		user1.setSex("不详");
		userMapper.insertUser(user1);
		
		//调用 updateUserById() 方法
		User user2 = new User();
		user2.setId(6);
		user2.setUsername("lbj");
		userMapper.updateUserById(user2);
		
		//调用 () 方法
		userMapper.deleteUserById(6);
		
		session.commit();
		session.close();
	}
}