public static int getWorkingDay(int month){ if (1<=month&&month<=12){ Calendar cal = Calendar.getInstance(); cal.set(2016,month,1); cal.add(Calendar.DATE,-1); int dayOfWeek = cal.get(Calendar.DAY_OF_WEEK); if (dayOfWeek==7){ cal.add(Calendar.DATE,-1); }else if (dayOfWeek==1){ cal.add(Calendar.DATE,-2); } return cal.get(Calendar.DATE); }else { throw new IllegalArgumentException("月份有误!"); } }