MyBatis基本方式一复习

一、基本引入

1、配置

mysql8+myBatis

教程：狂神

官网：入门_MyBatis中文网

项目地址：地址项目目录

    4.0.0

    org.example
    games
    pom
    1.0-SNAPSHOT
// 子项目名fly
    
        fly
    
// 依赖 myBatis mysql junit
    
        
            org.mybatis
            mybatis
            3.5.6
        
        
            mysql
            mysql-connector-java
            5.1.47
        
        
            junit
            junit
            4.12
        
    
// 配置maven环境 utf-8
    
        8
        8
        UTF-8
    
// 配置未在resource中导入，项目中的后缀名为xml和properties文件进入预加载
    
        
            
                src/main/resources
                
                    ***.xml
                
                true
            
            
                src/main/java
                
                    ***.xml
                
                true
            
        
    

子模块pom

    
        games
        org.example
        1.0-SNAPSHOT
    
    4.0.0

    fly

    
        
            
                src/main/resources
                
                    ***.xml
                
                true
            
            
                src/main/java
                
                    **/*.xml
                
                true
            
        
    

    
        8
        8
        UTF-8
    

项目目录结构：

 1、新建User类，

package com.npb.pojo;

public class User {
    private String username;
    private String id;
    private String password;

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


    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getPassword(){
        return password;
    }
    public void setPassword(String password){
        this.password=password;
    }
    public String getUsername(){
        return username;
    }
    public void setUsername(String username){
        this.username=username;
    }
}

对应

2、创建接口UserDao

package com.npb.dao;

import com.npb.pojo.User;

import java.util.List;

public interface UserDao {
    List getUserList();
}

3、连接数据库

新建MyBatisUtils类

package com.npb.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;

public class MyBatisUtils {
    private static SqlSessionFactory sqlSessionFactory;
    static {
// 数据库连接信息文件
        String resource = "mybatis-config.xml";
        InputStream inputStream = null;
        try {
            inputStream = Resources.getResourceAsStream(resource);
        } catch (IOException e) {
            e.printStackTrace();
        }
        sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
    }
// 当前连接
    public static SqlSession getSqlSession() {
        return sqlSessionFactory.openSession();
    }
}

新建mybatis-config.xml

    
        
            
            
                
                
                
                
            
        
    
// UserMapp.xml
// 
// 
// 
//    
//        select * from news.user
//    
//


    
        
    

4、新建UserMapper.xml

    
        select * from news.user
    

5、测试连接

package com.npb.dao;

import com.npb.pojo.User;
import com.npb.utils.MyBatisUtils;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;

import java.util.List;

public class UserDaoTest {

    @Test
    public void test() {
        SqlSession sqlSession = MyBatisUtils.getSqlSession();

        UserDao userDao = sqlSession.getMapper(UserDao.class);
        List userList = userDao.getUserList();
        for (User user : userList) {
            System.out.println(user);
        }
        sqlSession.close();
    }
}