Execution plan calculation for different time types

1. Problem description ：

To be described ...

2. Code ：

public class DateTimeUtil {
    
	private static final DateTimeFormatter DAY_FULL_FMT = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
	/** *  Get a list of all execution times by type and start time  * @param startTime  Starting time  * @param endTime  End time  * @param type  type ： day( God ), week( Zhou ), month( month ), quarter( quarter ), year( year ) * @return  List of execution dates  */
	public static List<String> getExecuteDaysByType(String type, LocalDateTime startTime, LocalDateTime endTime) {
    
		LocalDate startDate = startTime.toLocalDate(), endDate = endTime.toLocalDate();

		LocalDateTime now = LocalDateTime.now();
		LocalDate today = now.toLocalDate();

		if("day".equalsIgnoreCase(type)){
    
			if(startDate.isBefore(today)){
    
				startDate = today;
			}
			return getExecDays(startDate, endDate, now, date -> date.plusDays(1));
		}

		if("week".equalsIgnoreCase(type)){
    
			// Monday corresponding to the start time 
			startDate = startDate.minusDays(startDate.getDayOfWeek().getValue()-1);
			// This Monday 
			LocalDate currMonday = today.minusDays(today.getDayOfWeek().getValue()-1);

			if(startDate.isBefore(currMonday)){
    
				startDate = currMonday;
			}

			return getExecDays(startDate, endDate, now, date -> date.plusDays(7));
		}

		if("month".equalsIgnoreCase(type)){
    
			// The starting time is in the current month 1 Number 
			startDate = LocalDate.of(startDate.getYear(), startDate.getMonthValue(), 1);
			// This month, 1 Number 
			LocalDate currMonth = LocalDate.of(today.getYear(), today.getMonthValue(), 1);

			if(startDate.isBefore(currMonth)){
    
				startDate = currMonth;
			}

			return getExecDays(startDate, endDate, now, date -> date.plusMonths(1));
		}
		if("quarter".equalsIgnoreCase(type)){
    
			// Start in the first month of the quarter 1 Number 
			startDate = LocalDate.of(startDate.getYear(), startDate.getMonth().firstMonthOfQuarter(), 1);
			// The first month of this quarter 1 Number 
			LocalDate currQuarter = LocalDate.of(today.getYear(), today.getMonth().firstMonthOfQuarter(), 1);

			if(startDate.isBefore(currQuarter)){
    
				startDate = currQuarter;
			}

			return getExecDays(startDate, endDate, now, date -> date.plusMonths(3));
		}
		if("year".equalsIgnoreCase(type)){
    
			// Start in the first month of the year 1 Number 
			startDate = LocalDate.of(startDate.getYear(), 1, 1);
			// First month of the year 1 Number 
			LocalDate currYear = LocalDate.of(today.getYear(), 1, 1);

			if(startDate.isBefore(currYear)){
    
				startDate = currYear;
			}

			return getExecDays(startDate, endDate, now, date -> date.plusYears(1));
		}

		return Collections.emptyList();
	}

	private static List<String> getExecDays(LocalDate startDate, LocalDate endDate, LocalDateTime now, Function<LocalDate, LocalDate> timePlus){
    
		LocalDate today = now.toLocalDate();
		List<String> execDays = new ArrayList<>();

		while(!startDate.isAfter(endDate)){
    
			if(!startDate.isAfter(today)){
    
				// The execution time is today and before today , At the current time 5 Execute in minutes 
				execDays.add(now.plusMinutes(5).format(DAY_FULL_FMT));
			}else{
    
				execDays.add(startDate.atStartOfDay().format(DAY_FULL_FMT));
			}
			// Next execution date 
			startDate = timePlus.apply(startDate);
		}

		return execDays;
	}
}

4.Test:

public static void main(String[] args) {
    
	LocalDateTime startTime = LocalDateTime.of(2020, 7, 1, 12, 0, 0);
	LocalDateTime endTime = LocalDateTime.of(2022, 6, 1, 0, 0, 0);
	System.out.println(DateTimeUtil.getExecuteDaysByType("year", startTime, endTime));
}