简单说：得到某一月份的第一天，第一小时，第一分钟，第一秒和某一月份的最后一天，最后一小时，最后一分钟，最后一秒。

实现：

1 //月初 2 private Date getBeginTimeOfMonth(int year , int month){ 3         Calendar c = Calendar.getInstance(); 4         c.set(Calendar.YEAR,year); 5         c.set(Calendar.MONTH,month-1); 6         c.set(Calendar.DAY_OF_MONTH,1); 7         c.set(Calendar.HOUR_OF_DAY,0); 8         c.set(Calendar.MINUTE,0); 9         c.set(Calendar.SECOND,0);10         c.set(Calendar.MILLISECOND,0);11         return c.getTime();12     }13 //月末14 private Date getEndTimeOfMonth(int year , int month){15         Calendar c = Calendar.getInstance();16         c.set(Calendar.YEAR,year);17         c.set(Calendar.MONTH,month-1);18         int lastDate = c.getActualMaximum(Calendar.DATE);19         c.set(Calendar.DAY_OF_YEAR,lastDate);20         c.set(Calendar.HOUR_OF_DAY,23);21         c.set(Calendar.MINUTE,59);22         c.set(Calendar.SECOND,59);23         c.set(Calendar.MILLISECOND,999);24         return c.getTime();25     }