SMM筆記——入門案例（自己寫Dao實現類）

在實際開發中不需要自己寫dao實現類。

1、創建UserDaoImpl.java實現類

com.ccut.dao.impl  UserDaoImpl.java

package com.ccut.test;

import com.ccut.dao.IUserDao;
import com.ccut.dao.impl.UserDaoImpl;
import com.ccut.domain.User;
import com.mysql.cj.xdevapi.SessionFactory;
import org.apache.ibatis.io.Resources;
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 MybatisTest {

    public static void main(String[] args) throws IOException {
        //1、讀取配置文件
        InputStream in= Resources.getResourceAsStream("SqlMapConfig.xml");
        //2、創建SqlSessionFactory工廠
        SqlSessionFactoryBuilder builder=new SqlSessionFactoryBuilder();
        SqlSessionFactory factory=builder.build(in);
        //3、使用工廠創建dao對象
        IUserDao userDao=new UserDaoImpl(factory);
        List<User> users=userDao.findAll();
        for (User user : users) {
            System.out.println(user);
        }
        //釋放資源
        in.close();
    }

}

 

2、更改main測試方法

package com.ccut.test;

import com.ccut.dao.IUserDao;
import com.ccut.dao.impl.UserDaoImpl;
import com.ccut.domain.User;
import com.mysql.cj.xdevapi.SessionFactory;
import org.apache.ibatis.io.Resources;
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 MybatisTest {

    public static void main(String[] args) throws IOException {
        //1、讀取配置文件
        InputStream in= Resources.getResourceAsStream("SqlMapConfig.xml");
        //2、創建SqlSessionFactory工廠
        SqlSessionFactoryBuilder builder=new SqlSessionFactoryBuilder();
        SqlSessionFactory factory=builder.build(in);
        //3、使用工廠創建dao對象
        IUserDao userDao=new UserDaoImpl(factory);
        List<User> users=userDao.findAll();
        for (User user : users) {
            System.out.println(user);
        }
        //釋放資源
        in.close();
    }

}

 

3、運行結果