javaÈÕÆÚ

Date ---->String
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
String date = sdf.fomat(new Date());

String ---->Date
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Date date = sdf.parse("2010-03-16");

ÈÕÆڱȽϴóС£¬Õâ¾ÍÓõ½ÁËDateÀàÖеÄbefore()ºÍafter()·½·¨¡£¾ßÌå²Î¼ûapi
ÈÕÆÚÔËËã»áÓõ½CalendarÀ࣬×î³£ÓõÄÊÇadd(int field,int amount)Õâ¸ö·½·¨¡£fieldÑ¡ÔñYEAR  MONTH  DAY_OF_MONTHÆäÖеÄÒ»¸ö
amountΪÔö´óµÄÊýÁ¿¡£
String ¡¢Date¡¢CalendarÈýÕßÖ®¼ä³£¼ûÅäºÏ
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
String dateStr = "2010-3-16";
Date date = sdf.parse(dateStr);
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);//ʹÓøø¶¨µÄDateÉèÖÃ´Ë Calendar µÄʱ¼ä
calendar.add(DAY_OF_MONTH,2);//½«¸ø¶¨ÈÕÆÚµÄÕâ¸öÔµÄÈÕ¼Ó2
//´ÓCalendar-->Date
Date temp = calendar.getTime();
while(date.before(temp)){
}...