用途：在项目中一些属性中设置当前时间

 实例代码

import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;


public class time {

    public  static void  main(String[] args){


        LocalDateTime china = LocalDateTime.now(); 
        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
        System.out.println((china.format(formatter)));
    }
}

 运行结果