mybatis-mybatis入门

1.建数据库

2.使用maven导入mybatis需要的jar包

    mysql
    mysql-connector-java
    5.1.47



    org.mybatis
    mybatis
    3.5.2

3.编写mybatis核心配置文件

<?xml version="1.0" encoding="UTF8" ?>


    
        
            
            
                
                
                
                
            
        
    
    
    
        
    

4.编写mybatis工具类

package com.kuang.Utils;

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;

//sqlSessionFactory --> sqlSession
public class MybatisUtils {

    private static SqlSessionFactory sqlSessionFactory;

    static{
        try {
            //使用Mybatis第一步：获取sqlSessionFactory对象
            String resource = "mybatis-config.xml";
            InputStream inputStream = Resources.getResourceAsStream(resource);
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    //既然有了 SqlSessionFactory，顾名思义，我们就可以从中获得 SqlSession 的实例了。
    // SqlSession 完全包含了面向数据库执行 SQL 命令所需的所有方法。
    public static SqlSession  getSqlSession(){
        return sqlSessionFactory.openSession();
    }
}

5.创建实体类

package com.lv.pojo;

//实体类
public class User {
    private int id;
    private String name;
    private String pwd;

    public User() {
    }

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

    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 + '\'' +
                '}';
    }
}

6.编写Mapper接口类

package com.lv.dao;

import com.lv.pojo.User;

import java.util.List;

public interface UserMapper {
    List getUserList();
}

7.编写Mapper.xml配置文件

<?xml version="1.0" encoding="UTF8" ?>


    
        select * from mybatis.user
    

8.使用测试类进行测试

package com.lv.dao;

import com.lv.Utils.MybatisUtils;
import com.lv.pojo.User;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;

import java.util.List;

public class myTest {
    @Test
    public void getUserList(){
        SqlSession session = MybatisUtils.getSqlSession();

        UserMapper mapper = session.getMapper(UserMapper.class);
        List userList = mapper.getUserList();

        for (User user : userList) {
            System.out.println(user);
        }
        session.close();
    }
}

9.测试结果