mybatis初见：HelloWorld

configuration.xml代码如下：

<?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>
	<typeAliases>
		<typeAlias type="com.mybatis.bean.User" alias="User" />
	</typeAliases>
	<environments default="development">
	  <environment id="development">
	    <transactionManager type="JDBC"/>
	     <dataSource type="POOLED">
	       <property name="driver" value="com.mysql.jdbc.Driver"/>
	       <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useUnicode=true&amp;characterEncoding=UTF-8"/>
	       <property name="username" value="root"/>
	       <property name="password" value="admin"/>
	     </dataSource>
	  </environment>
	</environments>
	<mappers>
	 <mapper resource="com/mybatis/bean/User.xml"/>
	</mappers>
</configuration>

User.java代码如下：

package com.mybatis.bean;

public class User {
	
	private int id;
	
	private String name;

	public User(){
		
	}
	
	public User(int id,String name){
		this.id = id;
		this.name = name;
	}
	
	public int getId() {
		return id;
	}

	public void setId(int id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}
	
	@Override
	public String toString(){
		return "User [ id = "+id+",name = "+name+"];";
	}
	
}

User.xml代码如下：

<?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="User">
	 <select id="selectUser" parameterType="int" resultType="User">
	    select * from user where id=#{id}
	 </select>
	</mapper>

Test.java代码如下：

package com.mybatis.test;

import java.io.Reader;

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.mybatis.bean.User;

public class Test {
	public static void main(String[] args) throws Exception{
		
		String resource = "configuration.xml";
		Reader reader = Resources.getResourceAsReader(resource);
		SqlSessionFactory ssf = new SqlSessionFactoryBuilder().build(reader);
		SqlSession session = ssf.openSession();
		reader.close();
		try{
			User user = (User)session.selectOne("selectUser","1");
			System.out.println(user);
		}catch (Exception e) {
			e.printStackTrace();
		}finally{
			session.close();
		}
	}

}

数据库表中数据为：



运行结果为：

User [ id = 1,name = yangjianzhou];