import java.util.Date;
import java.util.Calendar;
import java.text.SimpleDateFormat;
public class SystemTime
{
    public static void main(String[] args)
    {
        Calendar cal=Calendar.getInstance();
        //-0代表0天前这个时候的时间
        cal.add(Calendar.DAY_OF_YEAR,-0);
        SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        String nowtime=sdf.format(cal.getTime());
        System.out.println(nowtime);
    }
}