java中计算时间差
Calendar cale = null; SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); Date d = new Date(); //获取当前时间 String startDate =format.format(d); // 获取前月的第一天
cale = Calendar.getInstance();
cale.add(Calendar.MONTH, 0);
cale.set(Calendar.DAY_OF_MONTH, 1);
firstday = format.format(cale.getTime());
// 获取前月的最后一天 cale = Calendar.getInstance(); cale.add(Calendar.MONTH, 1); cale.set(Calendar.DAY_OF_MONTH, 0); cale.set(Calendar.HOUR_OF_DAY,23); cale.set(Calendar.MINUTE,59); cale.set(Calendar.SECOND,59); String endDate = format.format(cale.getTime());
获取当前时间的前一天或者前几天时间
Date date=new Date();
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
calendar.add(Calendar.DAY_OF_MONTH, -1);
date = calendar.getTime();
计算时间差
DateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); try { Date d1 = df.parse("2008-03-26 13:31:40"); Date d2 = df.parse("2008-01-02 11:30:24"); long diff = d1.getTime() - d2.getTime(); long days = diff / (1000 * 60 * 60 * 24); } catch (Exception e) { }