Java中計(jì)算兩個(gè)日期相差幾天

public class Test {
public void dateDiff(String startTime, String endTime, String format) {
//按照傳入的格式生成一個(gè)simpledateformate對象
SimpleDateFormat sd = new SimpleDateFormat(format);
long nd = 1000*24*60*60;//一天的毫秒數(shù)
long nh = 1000*60*60;//一小時(shí)的毫秒數(shù)
long nm = 1000*60;//一分鐘的毫秒數(shù)
long ns = 1000;//一秒鐘的毫秒數(shù)
long diff;
try {
//獲得兩個(gè)時(shí)間的毫秒時(shí)間差異
diff = sd.parse(endTime).getTime() - sd.parse(startTime).getTime();
long day = diff/nd;//計(jì)算差多少天
long hour = diff%nd/nh;//計(jì)算差多少小時(shí)
long min = diff%nd%nh/nm;//計(jì)算差多少分鐘
long sec = diff%nd%nh%nm/ns;//計(jì)算差多少秒
//輸出結(jié)果
System.out.println("時(shí)間相差："+day+"天"+hour+"小時(shí)"+min+"分鐘"+sec+"秒。");
} catch (ParseException e) {
e.printStackTrace();
}
}

public static void main(String[] args) {
new Test().dateDiff(new SimpleDateFormat("yyyy-MM-dd").format(new Date()), "2011-4-28", "yyyy-MM-dd");
}
}