Mybatis之Mapper动态代理实例解析

package com.kang.mapper;
import java.util.List;
import com.kang.pojo.User;
public interface UserMapper {
	//根据用户id查询用户信息
	public User findUserById(int id) throws Exception;
	//查询用户列表
	public List<User> findUserByUsername(String username) throws Exception;
	//添加用户信息
	public void insertUser(User user)throws Exception; 
}

<?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.kang.mapper.UserMapper">
<!-- 注意这里的 namespace必须对应着map接口的全类名-->
	<select id="findUserById" parameterType="int" resultType="user">
		select * from user where id = #{id}
	</select>	
	<select id="findUserByUsername" parameterType="java.lang.String"
		resultType="user">
		select * from user where username like '%${value}%'
	</select>	
	<insert id="insertUser" parameterType="user">
		<selectKey keyProperty="id" order="AFTER" resultType="java.lang.Integer">
			select LAST_INSERT_ID()
		</selectKey>
		insert into user(username,birthday,sex,address)
		values(#{username},#{birthday},#{sex},#{address})
	</insert>
</mapper>

<!-- 加载 映射文件 -->
	<mappers>
		<mapper resource="map/UserMapper.xml" />
    </mappers>

package com.kang.test;
import java.io.IOException;
import java.io.InputStream;
import java.util.Date;
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 org.junit.Before;
import org.junit.Test;
import com.kang.mapper.UserMapper;
import com.kang.pojo.User;
public class UserTest {
	// 会话工厂
	private SqlSessionFactory sqlSessionFactory;
	@Before
	public void createSqlSessionFactory() throws IOException {
		// 配置文件SqlMapConfig.xml在类路径下
		String resource = "SqlMapConfig.xml";
		// 得到配置文件流
		InputStream inputStream = Resources.getResourceAsStream(resource);
		// 创建会话工厂，传入mybatis的配置文件信息
		sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
	}
	@Test
	public void testFindUserById() throws Exception {
		//获取session
		SqlSession session = sqlSessionFactory.openSession();
		//获取mapper接口的代理对象
		UserMapper userMapper = session.getMapper(UserMapper.class);
		//调用代理对象方法
		User user = userMapper.findUserById(27);
		System.out.println(user);
		//关闭session
		session.close();
		System.out.println("---------执行完毕-----------");		
	}	
	@Test
	public void testFindByUsername() throws Exception{
		//获取session
		SqlSession session = sqlSessionFactory.openSession();
		//获取mapper接口的代理对象
		UserMapper userMapper = session.getMapper(UserMapper.class);
		//调用代理对象方法
		List<User> list=userMapper.findUserByUsername("张");
		for (User user : list) {
			System.out.println(user);
		}
		//关闭session
		session.close();
		System.out.println("---------执行完毕-----------");
	}	
	@Test
	public void testInsert() throws Exception{
		User user=new User();
		user.setUsername("cxk");
		user.setSex("1");
		user.setBirthday(new Date());
		user.setAddress("四川成都");	
		SqlSession session=sqlSessionFactory.openSession();
		UserMapper userMapper=session.getMapper(UserMapper.class);
		userMapper.insertUser(user);
		session.commit();
		//关闭session
		session.close();
		System.out.println("---------执行完毕-----------");	
	}
}