Yes, @DefaultValue https://javaee.github.io/javaee-spec/javadocs/javax/ws/rs/DefaultValue.html在这种情况下可以使用值:
@GET
public Response foo(@QueryParam("start") @DefaultValue("today") LocalDate start,
@QueryParam("end") @DefaultValue("max") LocalDate end) {
...
}
Your ParamConverterProvider https://javaee.github.io/javaee-spec/javadocs/javax/ws/rs/ext/ParamConverterProvider.html and ParamConverter https://javaee.github.io/javaee-spec/javadocs/javax/ws/rs/ext/ParamConverter.html实现可以是这样的:
@Provider
public class LocalDateParamConverterProvider implements ParamConverterProvider {
@Override
public <T> ParamConverter<T> getConverter(Class<T> rawType, Type genericType,
Annotation[] annotations) {
if (rawType.getName().equals(LocalDate.class.getName())) {
return new ParamConverter<T>() {
@Override
public T fromString(String value) {
return parseString(value, rawType);
}
@Override
public String toString(T value) {
return ((LocalDateTime) value)
.format(DateTimeFormatter.ISO_LOCAL_DATE);
}
};
}
return null;
}
private <T> T parseString(String value, Class<T> rawType) {
if (value == null) {
return null;
}
if ("today".equalsIgnoreCase(value)) {
return rawType.cast(LocalDate.now());
}
if ("max".equalsIgnoreCase(value)) {
return rawType.cast(LocalDate.of(9999, 12, 31));
}
try {
return rawType.cast(LocalDate.parse(value,
DateTimeFormatter.ISO_LOCAL_DATE));
} catch (Exception e) {
throw new BadRequestException(e);
}
}
}
如果由于某种原因您需要参数名称,您可以从Annotation
array:
Optional<Annotation> optional = Arrays.stream(annotations)
.filter(annotation -> annotation.annotationType().equals(QueryParam.class))
.findFirst();
if (optional.isPresent()) {
QueryParam queryParam = (QueryParam) optional.get();
String parameterName = queryParam.value();
}