JAVA工具类【时间】

public class DateUtils {


	public static final String DATE_PATTERN = "yyyy-MM-dd";
	public static final String DATE_YM_PATTERN = "yyyyMM";
	public static final String DATE_TIME_PATTERN = "yyyy-MM-dd HH:mm:ss";
	
	public static LocalDate parseDate(String date, String pattern) {
		DateTimeFormatter formatter = DateTimeFormatter.ofPattern(pattern);
		return LocalDate.parse(date, formatter);
	}

	
	public static LocalDateTime parseDateTime(String dateTime, String pattern) {
		DateTimeFormatter formatter = DateTimeFormatter.ofPattern(pattern);
		return LocalDateTime.parse(dateTime, formatter);
	}

	
	public static String parseString(LocalDate date, String pattern) {
		if (Objects.isNull(date)) {
			return "";
		}
		DateTimeFormatter formatter = DateTimeFormatter.ofPattern(pattern);
		return formatter.format(date);
	}

	
	public static String parseString(LocalDateTime dateTime, String pattern) {
		if (Objects.isNull(dateTime)) {
			return "";
		}
		DateTimeFormatter formatter = DateTimeFormatter.ofPattern(pattern);
		return formatter.format(dateTime);
	}

	
	public static Long toMillisecond(LocalDateTime dateTime) {
		return dateTime.toInstant(ZoneOffset.of("+8")).toEpochMilli();
	}

	
	public static Long toMillisecond(LocalDate date) {
		LocalDateTime dateTime = date.atStartOfDay();
		return dateTime.toInstant(ZoneOffset.of("+8")).toEpochMilli();
	}

	
	public static String getWeekDateOfDay(String date){
		LocalDate localDate = LocalDate.parse(date);
		int year = localDate.get(WeekFields.ISO.weekBasedYear());
		int week = localDate.get(WeekFields.ISO.weekOfWeekBasedYear());
		String weekDate = week>=10 ? year + "" + week : year + "0" + week;

		return weekDate;
	}

	
	public static LocalDate getDayOfWeek(String category, long newValue){
		int year = Integer.valueOf(category.substring(0,4));
		int numWeek = Integer.valueOf(category.substring(4,6));
		WeekFields weekFields= WeekFields.ISO;
		LocalDate now = LocalDate.now();
		LocalDate localDate = now.withYear(year).with(weekFields.weekOfYear(),numWeek);
		LocalDate goalLocalDate  = localDate.with(weekFields.dayOfWeek(), newValue);
		return goalLocalDate;
	}
}