Mybatis基本使用

大致思路：测试类创建实体类的实例，通过接口的引用将实体类对象传入到配置文件UserMapper.xml中实现与数据库数据的交互

①添加MyBatis的jar包

②创建user数据表

③编写User实体类

package com.Mybatis;

public class User {
    private int id;
    private String name;
    private String pwd;

    public User() {
    }

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

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

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

④编写映射文件UserMapper.xml

    
    
                SELECT *  FROM `user`
            

 
        INSERT INTO `user` VALUES(NULL,#{name},#{pwd})
    

    
        delete from `user` where id=#{id}
    
    
        UPDATE  USER SET NAME=#{name} ,pwd=#{pwd} WHERe id=#{id}
    

⑤编写核心文件Config.xml

⑥编写工具类MybatisUtil

package com.Mybatis;

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 MybatisUtil {
    private static final SqlSessionFactory sqlSessionFactory;
    static {
        InputStream resourceAsStream = null;
        try {
            resourceAsStream = Resources.getResourceAsStream("Config.xml");
        } catch (IOException e) {
            e.printStackTrace();
        }
        //创建SQLSessionFactory对象
        sqlSessionFactory = new SqlSessionFactoryBuilder().build(resourceAsStream);

        //获取SqlSession对象
        SqlSession sqlSession = sqlSessionFactory.openSession();
    }
    public static SqlSession getSqlsession() {
        return sqlSessionFactory.openSession();
    }
}

⑦编写测试类

package com.itHe;

import org.apache.ibatis.session.SqlSession;
import org.junit.Before;
import org.junit.Test;

import java.util.Iterator;
import java.util.List;

public class Test1 {
    UserMapper mapper;
    SqlSession sqlsession;
    @Before
    public void Before() {
         sqlsession = Util.getSqlsession();
         mapper = sqlsession.getMapper(UserMapper.class);
    }
    @Test
    public void inser() {
        User user = new User("王老五", "10086");
//        User user1 = new User(80, "王鑫", "110");
        mapper.insertUser(user);
        sqlsession.commit();
        sqlsession.close();
    }
    @Test
    public void delete() {
        mapper.deleteUser(6);
        sqlsession.commit();
        sqlsession.close();
    }
@Test
    public void update() {
        User user = new User(5, "詹姆斯", "189898");
        mapper.updateUser(user);
        sqlsession.commit();
        sqlsession.close();
    }
    @Test
    public void query() {
        List users = mapper.queryUser();
        Iterator iterator = users.iterator();
        while (iterator.hasNext()) {
            System.out.println(iterator.next());
        }
    }
}