Package com.linecorp.armeria.server.annotation

Interface ResponseConverterFunction

All Known Implementing Classes:

ByteArrayResponseConverterFunction, HttpFileResponseConverterFunction, JacksonResponseConverterFunction, NullToNoContentResponseConverterFunction, ObservableResponseConverterFunction, ObservableResponseConverterFunction, ProtobufResponseConverterFunction, ServerSentEventResponseConverterFunction, StringResponseConverterFunction

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface ResponseConverterFunction

Converts a result object to HttpResponse. The class implementing this interface would be specified as ResponseConverter annotation.

See Also:

• ResponseConverter

Method Summary

Modifier and Type	Method	Description
HttpResponse	convertResponse(ServiceRequestContext ctx, ResponseHeaders headers, @Nullable Object result, HttpHeaders trailers)	Returns HttpResponse instance corresponds to the given result.
static <T> T	fallthrough()	Throws a FallthroughException in order to try to convert result to HttpResponse by the next converter.
default @Nullable Boolean	isResponseStreaming(Type returnType, @Nullable MediaType produceType)	Returns whether an HttpResponse of an annotated service should be streamed.

Method Details

isResponseStreaming

@UnstableApi
@Nullable
default @Nullable Boolean isResponseStreaming(Type returnType,
 @Nullable
 @Nullable MediaType produceType)

Returns whether an HttpResponse of an annotated service should be streamed. null if this converter cannot convert the responseType to an HttpResponse. true can be returned if the response is a streaming type, or the ResponseConverterFunction has not been optimized for the responseType through overriding this method for backward compatibility.

This method is used as a performance optimization hint. If the returnType and produceType are not a streaming response, it is recommended to return false for the better performance.

Note that you should never return false for a streaming response. The non-streaming response is aggregated before being sent.

Parameters:

returnType - the return type of the annotated service.

produceType - the negotiated producible media type of the annotated service. null if the media type negotiation is not used for the service.

convertResponse

@CheckReturnValue
HttpResponse convertResponse(ServiceRequestContext ctx,
 ResponseHeaders headers,
 @Nullable
 @Nullable Object result,
 HttpHeaders trailers)
                      throws Exception

Returns HttpResponse instance corresponds to the given result. Calls fallthrough() if this converter cannot convert the result to the HttpResponse.

Parameters:

headers - The HTTP headers that you might want to use to create the HttpResponse. The status of headers is HttpStatus.OK by default or HttpStatus.NO_CONTENT if the annotated method returns void, unless you specify it with StatusCode on the method. The headers also will include a MediaType if ServiceRequestContext.negotiatedResponseMediaType() returns it. If the method returns HttpResult, this headers is the same headers from HttpResult.headers() Please note that the additional headers set by ServiceRequestContext.mutateAdditionalResponseHeaders(Consumer) and AdditionalHeader are not included in this headers.

result - The result of the service method.

trailers - The HTTP trailers that you might want to use to create the HttpResponse. If the annotated method returns HttpResult, this trailers is the same trailers from HttpResult.trailers(). Please note that the additional trailers set by ServiceRequestContext.mutateAdditionalResponseTrailers(Consumer) and AdditionalTrailer are not included in this trailers.

Throws:

Exception

fallthrough

static <T> T fallthrough()

Throws a FallthroughException in order to try to convert result to HttpResponse by the next converter.