给定日期对象如何确定其月份的最后一天？

我正在尝试使用以下代码,但它每月都会返回错误的日期.

Calendar cal = Calendar.getInstance();
cal.setTime(sampleDay.getTime());
cal.set(Calendar.MONTH, sampleDay.get(Calendar.MONTH)+1);
cal.set(Calendar.DAY_OF_MONTH, 0);
return cal.getTime();

Argelbargel.. 17

获取本月的天数:

Calendar cal = Calendar.getInstance();
cal.setTime(sampleDay.getTime());
int noOfLastDay = cal.getActualMaximum(Calendar.DAY_OF_MONTH);

将日历设置为本月的最后一天:

Calendar cal = Calendar.getInstance();
cal.setTime(sampleDay.getTime());
cal.set(Calendar.DAY_OF_MONTH, cal.getActualMaximum(Calendar.DAY_OF_MONTH));

获取本月的天数:

Calendar cal = Calendar.getInstance();
cal.setTime(sampleDay.getTime());
int noOfLastDay = cal.getActualMaximum(Calendar.DAY_OF_MONTH);

将日历设置为本月的最后一天:

Calendar cal = Calendar.getInstance();
cal.setTime(sampleDay.getTime());
cal.set(Calendar.DAY_OF_MONTH, cal.getActualMaximum(Calendar.DAY_OF_MONTH));