Mybatis入门案例

Mybatis入门案例

1.导入jar包

            mysql
            mysql-connector-java
            5.1.47
        
        
            org.mybatis
            mybatis
            3.5.6
        

2.创建实例类

package com.zq.pojo;


public class User {
    private int id; //id
    private String name; //姓名
    private String pwd; //密码

    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 String getPwd() {
        return pwd;
    }

    public void setPwd(String pwd) {
        this.pwd = pwd;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + ''' +
                ", pwd='" + pwd + ''' +
                '}';
    }
}

3.创建接口

package com.zq.dao;

import com.zq.pojo.User;

import java.util.List;


public interface UserDao {
    List selectUser();
}

4.创建接口对应的映射文件UserDao Mapper.xml

    
    
    select * from user
  

5.配置mybatis核心配置文件，配置数据库连接信息，把Mapper映射文件注册到核心配置文中，在加载核心配置文件生成SqlseesionFactory时，能够通过SqlsessionFactory生成Sqlsession获得注册在核心配置文件中的mapper接口映射，获得mapper接口就能为所欲为。

6.测试

import com.zq.dao.UserDao;
import com.zq.pojo.User;
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 java.io.IOException;
import java.io.InputStream;
import java.util.List;


public class Testq {
    public static void main(String[] args) throws IOException {

        //读取核心xml中的数据库连接信息，生成SQLSessionFactory，当连接进来就生成session
        //生成Sqlsession就能为所欲为
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);

        try (SqlSession session = sqlSessionFactory.openSession()) {
            UserDao mapper = session.getMapper(UserDao.class);
            List objects1 = (List) mapper.selectUser();
            for (User user : objects1) {
                System.out.println(user);
            }
        }
    }
}