mybatis--第一个mybatis程序

首先，创建一个数据库my，并在数据库中插入一张表user，然后在user表中插入一行数据，代码如下：

create database my;
 
use my;
create table user(
id int(10) auto_increment,
name varchar(64),
level varchar(256),
phone varchar(256),
primary key(id)
);
 
insert into user(id,name,level,phone) values(1,'a','a','1234555666');

项目目录如下：

其次，创建mybatis配置文件SqlMapConfig.xml，配置文件代码如下：

<?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 alias="User" type="com.zk.pojo.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/my"/>
        <property name="username" value="root"/>
        <property name="password" value="123456"/>
        </dataSource>
        </environment>
    </environments>
 
    <mappers>
         <!-- // power by http://www.yiibai.com -->
         <mapper resource="com/zk/pojo/UserMapper.xml" />
    </mappers>
</configuration>

再次，创建实体类user.java和映射文件UserMapper.xml

user.java

package com.zk.pojo;
 
public class user {
    private Integer id;
     
    private String name;
     
    private String level;
     
    private String phone;
 
    public Integer getId() {
        return id;
    }
 
    public void setId(Integer id) {
        this.id = id;
    }
 
    public String getName() {
        return name;
    }
 
    public void setName(String name) {
        this.name = name;
    }
 
    public String getLevel() {
        return level;
    }
 
    public void setLevel(String level) {
        this.level = level;
    }
 
    public String getPhone() {
        return phone;
    }
 
    public void setPhone(String phone) {
        this.phone = phone;
    }
 
    @Override
    public String toString() {
        return "user [id=" + id + ", name=" + name + ", level=" + level
                + ", phone=" + phone + "]";
    }
}

UserMapper.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="com.zk.pojo.UserMapper">
    <select id="GetUserByID" parameterType="int" resultType="user">
        select * from user where id = #{id}
    </select>
</mapper>

最后，写出实现类Helloword.java

package com.zk.pojo;
 
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.zk.pojo.*;
 
/**
 * 
 * @author yiibai
 * @copyright http://www.yiibai.com
 * @date 2015/09/22
 */
public class HelloWord {
    private static SqlSessionFactory sqlSessionFactory;
    private static Reader reader;
 
    static {
        try {
            reader = Resources.getResourceAsReader("SqlMapConfig.xml");
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    public static SqlSessionFactory getSession() {
        return sqlSessionFactory;
    }
    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        SqlSession session = sqlSessionFactory.openSession();
        try {
            user user = (user) session.selectOne("com.zk.pojo.UserMapper.GetUserByID", 1);
            if(user!=null){
                String userInfo =user.getName()+", 所属部门："+user.getLevel()+", 手机号："+user.getPhone();
                System.out.println(userInfo);
            }
        } finally {
            session.close();
        }
    }
 
}