javaDate类和DateFormt类和Calendar类写可视化日历版本二，键盘实现输入

    Scanner scanner=new Scanner(System.in);   //创建输入对象
    String s=scanner.nextLine();               //获取输入字符串
    DateFormat it =new SimpleDateFormat("yyyy-MM-dd");
    Date d=it.parse(s);

    Calendar c= new GregorianCalendar();
    c.setTime(d);
    int day=c.get(Calendar.DAY_OF_MONTH);
    c.set(Calendar.DAY_OF_MONTH,1);

    System.out.println("日\t一\t二\t三\t四\t五\t六");
    for(int i=0;i