DurationToNumberConverter Class — spring-boot Architecture

Source Code

core/spring-boot/src/main/java/org/springframework/boot/convert/DurationToNumberConverter.java lines 38–69

final class DurationToNumberConverter implements GenericConverter {

	@Override
	public Set<ConvertiblePair> getConvertibleTypes() {
		return Collections.singleton(new ConvertiblePair(Duration.class, Number.class));
	}

	@Override
	public @Nullable Object convert(@Nullable Object source, TypeDescriptor sourceType, TypeDescriptor targetType) {
		if (source == null) {
			return null;
		}
		return convert((Duration) source, getDurationUnit(sourceType), targetType.getObjectType());
	}

	private @Nullable ChronoUnit getDurationUnit(TypeDescriptor sourceType) {
		DurationUnit annotation = sourceType.getAnnotation(DurationUnit.class);
		return (annotation != null) ? annotation.value() : null;
	}

	private Object convert(Duration source, @Nullable ChronoUnit unit, Class<?> type) {
		try {
			return type.getConstructor(String.class)
				.newInstance(String.valueOf(DurationStyle.Unit.fromChronoUnit(unit).longValue(source)));
		}
		catch (Exception ex) {
			ReflectionUtils.rethrowRuntimeException(ex);
			throw new IllegalStateException(ex);
		}
	}

}