自己写一个简单的MyBatis工具类代码+注释

package gua;

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;


/**
 * zt
 * 2020/9/27
 * 19:59
 */
public class MyBatisUtils {
    private static SqlSessionFactory sqlSessionFactory;
    //静态代码块，在方法调用之前调用,而且只调用一次
    static {
        System.out.println("在静态代码块中ongoing给sqlSessionFactory做初始化");
        try {
            //1.把配置文件转成一个流
            InputStream is = Resources.getResourceAsStream("mybatisConfig.xml");
            //2.初始化sqlSessionFactory
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(is);
        } catch (IOException e) {
            e.printStackTrace();
        }

    }
    public static SqlSession getSqlSession() {
        return sqlSessionFactory.openSession();
    }
}