Unit Type — spring-boot Architecture

Source Code

core/spring-boot/src/main/java/org/springframework/boot/convert/PeriodStyle.java lines 218–285

	private enum Unit {

		/**
		 * Days, represented by suffix {@code d}.
		 */
		DAYS(ChronoUnit.DAYS, "d", Period::getDays, Period::ofDays),

		/**
		 * Weeks, represented by suffix {@code w}.
		 */
		WEEKS(ChronoUnit.WEEKS, "w", null, Period::ofWeeks),

		/**
		 * Months, represented by suffix {@code m}.
		 */
		MONTHS(ChronoUnit.MONTHS, "m", Period::getMonths, Period::ofMonths),

		/**
		 * Years, represented by suffix {@code y}.
		 */
		YEARS(ChronoUnit.YEARS, "y", Period::getYears, Period::ofYears);

		private final ChronoUnit chronoUnit;

		private final String suffix;

		private final @Nullable Function<Period, Integer> intValue;

		private final Function<Integer, Period> factory;

		Unit(ChronoUnit chronoUnit, String suffix, @Nullable Function<Period, Integer> intValue,
				Function<Integer, Period> factory) {
			this.chronoUnit = chronoUnit;
			this.suffix = suffix;
			this.intValue = intValue;
			this.factory = factory;
		}

		private Period parse(String value) {
			return this.factory.apply(Integer.parseInt(value));
		}

		private String print(Period value) {
			return intValue(value) + this.suffix;
		}

		private boolean isZero(Period value) {
			return intValue(value) == 0;
		}

		private int intValue(Period value) {
			Assert.state(this.intValue != null, () -> "intValue cannot be extracted from " + name());
			return this.intValue.apply(value);
		}

		private static Unit fromChronoUnit(@Nullable ChronoUnit chronoUnit) {
			if (chronoUnit == null) {
				return Unit.DAYS;
			}
			for (Unit candidate : values()) {
				if (candidate.chronoUnit == chronoUnit) {
					return candidate;
				}
			}
			throw new IllegalArgumentException("Unsupported unit " + chronoUnit);
		}

	}