一眼想起MyBatis

实例警告：

Mybatis是一个操作数据库的框架，能避免很多的sql语句撰写的麻烦,也不用像jdbc那样繁琐，同样拥有hibernate的持久化操作

1. 实体类，User.java:

package MyBatisDemo;

public class User {
	private Integer uid;
	private String name;
	private int password;
	private Integer age;
	private String sex;
	
	public Integer getUid() {
		return uid;
	}
	public void setUid(Integer uid) {
		this.uid = uid;
	}
	public String getUserName() {
		return name;
	}
	//。。。此处省略其他getter方法
	@Override
	public String toString() {
		return "User [uid=" + uid + ", name=" + name + ", password=" + password + ", age=" + age + ", sex=" + sex + "]";
	}
	
	
	
}

2. 全局配置文件，xxx.xml：

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
 PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
 "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
 <environments default="development">
 <environment id="development">
 <transactionManager type="JDBC"/>
 <dataSource type="POOLED">
 <property name="driver" value="com.microsoft.sqlserver.jdbc.SQLServerDriver"/>
 <property name="url" value="jdbc:sqlserver://localhost:1433;databaseName=Userlist"/>
 <property name="username" value="sa"/>
 <property name="password" value="123456"/>
 </dataSource>
 </environment>
 </environments>
 <mappers>
 <mapper resource="UserMapper.xml"/>
 </mappers>
</configuration>

3.映射文件，xxxMapper.xml:

<?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="MyBatisDemo.UserMapper">
	<select id="getUserByUid" resultType="MyBatisDemo.User">
		select * from BaUser  where uid = #{id}
	</select>
</mapper>

4.接口类,UserMapper.java:

package MyBatisDemo;

public interface UserMapper {
	User getUserByUid(Integer uid);
	
}

5.最好测试,TestBa.java：

package MyBatisDemo;

import static org.junit.jupiter.api.Assertions.*;

import java.io.IOException;
import java.io.InputStream;

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.jupiter.api.Test;

class TestBa {

	@Test
	void test() throws IOException {
	
		/*
		 *  Mybatis 读取XML配置文件后会将内容放在一个Configuration类中，SqlSessionFactoryBuilder
		 *  会读取Configuration类中信息创建SqlSessionFactor,SqlSessionFactory创建SqlSession
		 */
		InputStream in=Resources.getResourceAsStream("mybatis-config.xml");
		SqlSessionFactory sqlSessionFactory=new 
				SqlSessionFactoryBuilder().build(in);
		SqlSession session= sqlSessionFactory.openSession();
		UserMapper mapper=session.getMapper(UserMapper.class);
		User user=mapper.getUserByUid(1);
		System.out.println(user);
		
		
	
	}

}

效果---->