java中roll()和add()之间的区别是什么？
/*这个我想看的课程,如果我可以使用添加代替roll.谢谢你*/
mydate.roll(Calendar.MINUTE, true);
int nextminutes = mydate.get(Calendar.MINUTE);
int nexttseconds = mydate.get(Calendar.SECOND);
while(count<1000000){
System.out.println(sentence);
GregorianCalendar now = new GregorianCalendar();
if(mydate.get(Calendar.MINUTE)>= nextminutes){
break;
}
}
count++;
System.out.println("i wrote the sentence"+count+"time.");
}
}