package demo2;public class User {    private int id;    private String name;    private int age;        public User(int id, String name, int age) {        super();        this.id = id;        this.name = name;        this.age = age;    }        public User()    {            }    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;    }    public int getAge() {        return age;    }    public void setAge(int age) {        this.age = age;    }    @Override    public String toString() {        return "User [id=" + id + ", name=" + name + ", age=" + age + "]";    }            }

<?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="demo2.userMapper">    <!--         根据id查询得到一个user对象     -->     <select id="getUser" parameterType="int" resultType="demo2.User">         select * from users where id=#{id}     </select>     <!-- 添加一个用户 -->     <insert id="insertUser" parameterType="demo2.User">          insert into users(name,age)values(#{name},#{age});     </insert>     <!-- 修改一个用户的信息 -->     <update id="updateUser"  parameterType="demo2.User">          update users set name=#{name},age=#{age} where id = #{id}          </update>          <delete id="deleteUser" parameterType="int">          delete from users where id = #{id}      </delete>         <select id="selectAllUsers" resultType="demo2.User">    select * from users    </select>                           </mapper>

<?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>    <properties resource="db.properties"/>        <!--     development : 开发模式    work : 工作模式 -->    <environments default="development">        <environment id="development">            <transactionManager type="JDBC" />            <dataSource type="POOLED">                <property name="driver" value="${driver}" />                <property name="url" value="${url}" />                <property name="username" value="${name}" />                <property name="password" value="${password}" />            </dataSource>        </environment>    </environments>        <mappers>                <mapper resource="demo2/userMapper.xml"/>            </mappers></configuration>

package Test;import java.io.InputStream;import org.apache.ibatis.session.SqlSession;import org.apache.ibatis.session.SqlSessionFactory;import org.apache.ibatis.session.SqlSessionFactoryBuilder;import java.util.List;import demo2.User;public class Test {    public static void main(String[] args) {        String resouse = "conf.xml";        //读取上上述的config.xml文件        InputStream is = Test.class.getClassLoader().getResourceAsStream(resouse);        SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(is);        SqlSession session = factory.openSession(true);//在这里如果配置成true就自动提交        String statement = "demo2.userMapper.getUser";                //User user = (User)session.selectOne(statement, 1);        String statement2 = "demo2.userMapper.updateUser";        int update = session.update(statement2, new User(1,"张三",14));               //删除User        String statement3 = "demo2.userMapper.deleteUser";        int delete = session.delete(statement3, 1);        //得到所有的用户                String statement4 = "demo2.userMapper.selectAllUsers";       List<User> list= session.selectList(statement4);                                      System.out.println(list);    }}