GregorianCalendar实现的日历

			GregorianCalendar cal = new GregorianCalendar();
			int today = cal.get(Calendar.DAY_OF_MONTH);
			int month = cal.get(Calendar.MONTH);
			cal.set(Calendar.DAY_OF_MONTH, 1);
			int week = cal.get(Calendar.DAY_OF_WEEK);
			
			System.out.println("  日   一   二   三   四   五   六");
			
			for (int i = Calendar.SUNDAY; i < week; i++) {
				System.out.println("    ");
			}
			do {
				int day = cal.get(Calendar.DAY_OF_MONTH);
				System.out.printf("%3d", day);
				if (day == today) {
					System.out.print("*");
				} else {
					System.out.print("");
				}
				if (week == Calendar.SATURDAY) {
					System.out.println();
				}
				cal.add(Calendar.DAY_OF_MONTH,1);
				week = cal.get(Calendar.DAY_OF_WEEK);
			} while(cal.get(Calendar.MONTH) == month);
			if (week != Calendar.SUNDAY)
				System.out.println();
		}