java 时间处理

1.获取下月月末日期

Calendar c = Calendar.getInstance();
c.add(Calendar.MONTH, 1);
c.set(Calendar.DAY_OF_MONTH, c.getActualMaximum(Calendar.DAY_OF_MONTH));
c.set(Calendar.HOUR_OF_DAY, c.getActualMaximum(Calendar.HOUR_OF_DAY));
c.set(Calendar.MINUTE, c.getActualMaximum(Calendar.MINUTE));
c.set(Calendar.SECOND, c.getActualMaximum(Calendar.SECOND));
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String activeTime = sdf.format(c.getTime());