Summary of Java's method to determine whether multiple time periods overlap

public class DateRangeStr {
    @JsonFormat(shape = , pattern="yyyy-MM", timezone = "GMT+8")
    private String startDate;//Format: yyyy-MM-dd    @JsonFormat(shape = , pattern="yyyy-MM", timezone = "GMT+8")
    private String endDate;//Format: yyyy-MM-dd}

//Judge whether there are time intervals for multiple time periods. True without intervals. False with intervals.    public boolean hasNoGaps(List<DateRangeStr> sortedStrRanges) {
        DateTimeFormatter formatter = ("yyyy-MM-dd");
        if (sortedStrRanges == null || () <= 0) return false;

        if (() == 1) return true;

        List<DateRange> timePeriods = new ArrayList<>();
        for (DateRangeStr ss : sortedStrRanges) {
            LocalDate startDate = ((), formatter);
            LocalDate endDate = ((), formatter);

            DateRange dr = new DateRange();
            (startDate);
            (endDate);
            (dr);
        }

        (timePeriods, (DateRange::getStartDate));

        LocalDate previousEndDate = (0).getEndDate();

        for (int i = 1; i < (); i++) {
            DateRange currentPeriod = (i);

            if ((())) {
                // The start date of the current time period is earlier than the end date of the previous time period, and there is overlap, which is not necessarily a problem                // But we still use the end date of the current time period as the new previousEndDate                previousEndDate = ();
            } else if ((!(()) && !(1L).isEqual(()))) {
                // The interval was found                return false;
            } else {
                // There is no interval between adjacent time periods                previousEndDate = ();
            }
        }

        return true; // All time periods have been traversed and no time intervals have been found    }

public class TimeInterval {
    @JsonFormat(shape = , pattern="yyyy-MM", timezone = "GMT+8")
    private String start;
    @JsonFormat(shape = , pattern="yyyy-MM", timezone = "GMT+8")
    private String end;
}

private static YearMonth parseYearMonth(String input) {
        try {
            return (input, MONTH_FORMATTER);
        } catch (Exception e) {
            throw new IllegalArgumentException("Invalid date format: " + input, e);
        }
    }

    public static boolean overlapsOrContainedInIntervals(List<TimeInterval> intervals, String startDate,String endDate) {
        YearMonth yearMonthAStart = parseYearMonth(startDate);
        YearMonth yearMonthAEnd =  parseYearMonth(endDate);

        for (TimeInterval interval : intervals) {
            YearMonth start = parseYearMonth(());
            YearMonth end = parseYearMonth(());

            // Check for overlap or inclusion            if (!(yearMonthAEnd) && !(yearMonthAStart)) {
                return true;
            }
        }

        return false;
    }