java获取当月日期和周末

根据年月，获取当月所有日期

  public static void main(String[] args) {
    
    
        System.err.println(getMonthDate("2022-07"));
    }

    public static List getMonthDate(String timeStamp){
    
    
        List list = new ArrayList();
        String[] split = timeStamp.split("-");
        String year = split[0];
        String month = split[1];
        Calendar calendar = Calendar.getInstance();
        calendar.set(Calendar.YEAR, Integer.parseInt(year));
        calendar.set(Calendar.MONTH, Integer.parseInt(month) - 1);
        int day = calendar.getActualMaximum(Calendar.DATE);
        for (int i = 1; i <= day; i++) {
    
    
            String days = "";
            if (i<10){
    
    
                days = "0"+i;
            }else {
    
    
                days = String.valueOf(i);
            }
            String aDate = year+"-"+month+"-"+days;
            list.add(aDate);
        }
        return list;
    }

根据年月，获取当月所有周末

 public static void main(String[] args) {
    
    
        System.err.println(getWeekend("2022-07"));
    }
    public static List getWeekend(String timeStamp) {
    
    
        List list = new ArrayList();
        String[] split = timeStamp.split("-");
        String year = split[0];
        String month = split[1];
        Calendar calendar = Calendar.getInstance();
        calendar.set(Calendar.YEAR, Integer.parseInt(year));
        calendar.set(Calendar.MONTH, Integer.parseInt(month) - 1);
        // 设置为当月第一天
        calendar.set(Calendar.DAY_OF_MONTH, 1);
        // 当月最大天数
        int daySize = calendar.getActualMaximum(Calendar.DAY_OF_MONTH);
        for (int i = 0; i < daySize - 1; i++) {
    
    
            String days = "";
            //在第一天的基础上加1
            calendar.add(Calendar.DATE, 1);
            int week = calendar.get(Calendar.DAY_OF_WEEK);
            // 1代表周日，7代表周六 判断这是一个星期的第几天从而判断是否是周末
            if (week == Calendar.SATURDAY || week == Calendar.SUNDAY) {
    
    
                int ct = calendar.get(Calendar.DAY_OF_MONTH);
                if (ct < 10) {
    
    
                    days = "0" + ct;
                } else {
    
    
                    days = String.valueOf(ct);
                }
                // 得到当天是一个月的第几天
                list.add(year + "-" + month + "-" + days);
            }
        }
        return list;
    }