Package com.linecorp.armeria.common

Interface HttpResponse

All Superinterfaces:

HttpMessage, org.reactivestreams.Publisher<HttpObject>, Response, StreamMessage<HttpObject>

All Known Subinterfaces:

HttpResponseWriter

All Known Implementing Classes:

FilteredHttpResponse

public interface HttpResponse
extends Response, HttpMessage

A streamed HTTP/2 Response.

Method Summary

Modifier and Type	Method	Description
default CompletableFuture<AggregatedHttpResponse>	aggregate()	Aggregates this response.
default CompletableFuture<AggregatedHttpResponse>	aggregate(EventExecutor executor)	Aggregates this response.
default CompletableFuture<AggregatedHttpResponse>	aggregateWithPooledObjects(ByteBufAllocator alloc)	(Advanced users only) Aggregates this response.
default CompletableFuture<AggregatedHttpResponse>	aggregateWithPooledObjects(EventExecutor executor, ByteBufAllocator alloc)	Aggregates this response.
default <T> StreamMessage<T>	decode(HttpDecoder<T> decoder, ByteBufAllocator alloc, Function<? super HttpData,? extends ByteBuf> byteBufConverter)	Creates a decoded StreamMessage which is decoded from a stream of HttpObjects using the specified HttpDecoder and ByteBufAllocator and byteBufConverter.
static HttpResponse	delayed(AggregatedHttpResponse response, Duration delay)	Creates a new HTTP response that delegates to the provided AggregatedHttpResponse, beginning publishing after delay has passed from a random ScheduledExecutorService.
static HttpResponse	delayed(AggregatedHttpResponse response, Duration delay, ScheduledExecutorService executor)	Creates a new HTTP response that delegates to the provided AggregatedHttpResponse, beginning publishing after delay has passed from the provided ScheduledExecutorService.
static HttpResponse	delayed(HttpResponse response, Duration delay)	Creates a new HTTP response that delegates to the provided HttpResponse, beginning publishing after delay has passed from a random ScheduledExecutorService.
static HttpResponse	delayed(HttpResponse response, Duration delay, ScheduledExecutorService executor)	Creates a new HTTP response that delegates to the provided HttpResponse, beginning publishing after delay has passed from the provided ScheduledExecutorService.
static HttpResponse	from(CompletionStage<? extends HttpResponse> stage)	Creates a new HTTP response that delegates to the HttpResponse produced by the specified CompletionStage.
static HttpResponse	from(CompletionStage<? extends HttpResponse> stage, EventExecutor subscriberExecutor)	Creates a new HTTP response that delegates to the HttpResponse produced by the specified CompletionStage.
default HttpResponse	mapData(Function<? super HttpData,? extends HttpData> function)	Transforms the HttpDatas emitted by this HttpRequest by applying the specified Function.
default HttpResponse	mapError(Function<? super Throwable,? extends Throwable> function)	Transforms an error emitted by this HttpResponse by applying the specified Function.
default HttpResponse	mapHeaders(Function<? super ResponseHeaders,? extends ResponseHeaders> function)	Transforms the non-informational ResponseHeaders emitted by HttpResponse by applying the specified Function.
default HttpResponse	mapInformational(Function<? super ResponseHeaders,? extends ResponseHeaders> function)	Transforms the informational headers emitted by HttpResponse by applying the specified Function.
default HttpResponse	mapTrailers(Function<? super HttpHeaders,? extends HttpHeaders> function)	Transforms the trailers emitted by this HttpResponse by applying the specified Function.
static HttpResponse	of(int statusCode)	Creates a new HTTP response of the specified statusCode.
static HttpResponse	of(HttpObject... objs)	Creates a new HTTP response of the specified objects.
static HttpResponse	of(HttpStatus status)	Creates a new HTTP response of the specified HttpStatus.
static HttpResponse	of(HttpStatus status, MediaType mediaType, byte[] content)	Creates a new HTTP response of the specified HttpStatus.
static HttpResponse	of(HttpStatus status, MediaType mediaType, HttpData content)	Creates a new HTTP response of the specified HttpStatus.
static HttpResponse	of(HttpStatus status, MediaType mediaType, HttpData content, HttpHeaders trailers)	Creates a new HTTP response of the specified HttpStatus.
static HttpResponse	of(HttpStatus status, MediaType mediaType, CharSequence content)	Creates a new HTTP response of the specified HttpStatus.
static HttpResponse	of(HttpStatus status, MediaType mediaType, String content)	Creates a new HTTP response of the specified HttpStatus.
static HttpResponse	of(HttpStatus status, MediaType mediaType, String format, Object... args)	Creates a new HTTP response of the specified HttpStatus.
static HttpResponse	of(MediaType mediaType, String content)	Creates a new HTTP response of OK status with the content.
static HttpResponse	of(MediaType mediaType, String format, Object... args)	Creates a new HTTP response of OK status with the content.
static HttpResponse	of(ResponseHeaders headers)	Creates a new HTTP response of the specified headers.
static HttpResponse	of(ResponseHeaders headers, HttpData content)	Creates a new HTTP response of the specified headers and content.
static HttpResponse	of(ResponseHeaders headers, HttpData content, HttpHeaders trailers)	Creates a new HTTP response of the specified objects.
static HttpResponse	of(ResponseHeaders headers, org.reactivestreams.Publisher<? extends HttpObject> publisher)	Creates a new HTTP response with the specified headers whose stream is produced from an existing Publisher.
static HttpResponse	of(String content)	Creates a new HTTP response of OK status with the content as UTF_8.
static HttpResponse	of(String format, Object... args)	Creates a new HTTP response of OK status with the content as UTF_8.
static HttpResponse	of(org.reactivestreams.Publisher<? extends HttpObject> publisher)	Creates a new HTTP response whose stream is produced from an existing Publisher.
static HttpResponse	ofFailure(Throwable cause)	Creates a new failed HTTP response.
static HttpResponse	ofJson(HttpStatus status, MediaType contentType, Object content)	Creates a new HTTP response with the specified HttpStatus, MediaType and content that is converted into JSON using the default ObjectMapper.
static HttpResponse	ofJson(HttpStatus status, Object content)	Creates a new HTTP response with the specified HttpStatus and content that is converted into JSON using the default ObjectMapper.
static HttpResponse	ofJson(MediaType contentType, Object content)	Creates a new HTTP response with the specified MediaType and content that is converted into JSON using the default ObjectMapper.
static HttpResponse	ofJson(ResponseHeaders headers, Object content)	Creates a new HTTP response with the specified ResponseHeaders and content that is converted into JSON using the default ObjectMapper.
static HttpResponse	ofJson(Object content)	Creates a new HTTP response with the specified content that is converted into JSON using the default ObjectMapper.
static HttpResponse	ofRedirect(HttpStatus redirectStatus, String location)	Creates a new HTTP response of the redirect to specific location.
static HttpResponse	ofRedirect(HttpStatus redirectStatus, String format, Object... args)	Creates a new HTTP response of the redirect to specific location using string format.
static HttpResponse	ofRedirect(String location)	Creates a new HTTP response of the temporary redirect to specific location.
static HttpResponse	ofRedirect(String format, Object... args)	Creates a new HTTP response of the temporary redirect to specific location using string format.
default HttpResponse	recover(Function<? super Throwable,? extends HttpResponse> function)	Recovers a failed HttpResponse by switching to a returned fallback HttpResponse when any error occurs before a ResponseHeaders is written.
default SplitHttpResponse	split()	Returns a new SplitHttpResponse which splits a stream of HttpObjects into HttpHeaders and HttpData.
default SplitHttpResponse	split(EventExecutor executor)	Returns a new SplitHttpResponse which splits a stream of HttpObjects into HttpHeaders and HttpData.
static HttpResponseWriter	streaming()	Creates a new HTTP response that can stream an arbitrary number of HttpObject to the client.
default HttpResponseDuplicator	toDuplicator()	Returns a new StreamMessageDuplicator that duplicates this StreamMessage into one or more StreamMessages, which publish the same elements.
default HttpResponseDuplicator	toDuplicator(long maxResponseLength)	Returns a new StreamMessageDuplicator that duplicates this HttpMessage into one or more HttpMessages, which publish the same elements.
default HttpResponseDuplicator	toDuplicator(EventExecutor executor)	Returns a new StreamMessageDuplicator that duplicates this StreamMessage into one or more StreamMessages, which publish the same elements.
default HttpResponseDuplicator	toDuplicator(EventExecutor executor, long maxResponseLength)	Returns a new StreamMessageDuplicator that duplicates this HttpMessage into one or more HttpMessages, which publish the same elements.
CompletableFuture<Void>	whenComplete()	Returns a CompletableFuture which completes when 1) the response stream has been closed (the StreamMessage has been completed) or 2) the result value is set (the CompletionStage has completed.)

Methods inherited from interface com.linecorp.armeria.common.HttpMessage

decode, decode

Methods inherited from interface com.linecorp.armeria.common.stream.StreamMessage

abort, abort, collect, collect, collect, defaultSubscriberExecutor, demand, filter, isComplete, isEmpty, isOpen, map, recoverAndResume, subscribe, subscribe, subscribe, subscribe

Method Details

streaming

static HttpResponseWriter streaming()

Creates a new HTTP response that can stream an arbitrary number of HttpObject to the client. The first object written must be of type ResponseHeaders.

from

static HttpResponse from(CompletionStage<? extends HttpResponse> stage)

Creates a new HTTP response that delegates to the HttpResponse produced by the specified CompletionStage. If the specified CompletionStage fails, the returned response will be closed with the same cause as well.

Parameters:

stage - the CompletionStage which will produce the actual HttpResponse

from

static HttpResponse from(CompletionStage<? extends HttpResponse> stage,
 EventExecutor subscriberExecutor)

Creates a new HTTP response that delegates to the HttpResponse produced by the specified CompletionStage. If the specified CompletionStage fails, the returned response will be closed with the same cause as well.

Parameters:

stage - the CompletionStage which will produce the actual HttpResponse

subscriberExecutor - the EventExecutor which will be used when a user subscribes the returned HttpResponse using StreamMessage.subscribe(Subscriber) or StreamMessage.subscribe(Subscriber, SubscriptionOption...).

delayed

static HttpResponse delayed(AggregatedHttpResponse response,
 Duration delay)

Creates a new HTTP response that delegates to the provided AggregatedHttpResponse, beginning publishing after delay has passed from a random ScheduledExecutorService.

delayed

static HttpResponse delayed(AggregatedHttpResponse response,
 Duration delay,
 ScheduledExecutorService executor)

Creates a new HTTP response that delegates to the provided AggregatedHttpResponse, beginning publishing after delay has passed from the provided ScheduledExecutorService.

delayed

static HttpResponse delayed(HttpResponse response,
 Duration delay)

Creates a new HTTP response that delegates to the provided HttpResponse, beginning publishing after delay has passed from a random ScheduledExecutorService.

delayed

static HttpResponse delayed(HttpResponse response,
 Duration delay,
 ScheduledExecutorService executor)

Creates a new HTTP response that delegates to the provided HttpResponse, beginning publishing after delay has passed from the provided ScheduledExecutorService.

of

static HttpResponse of(int statusCode)

Creates a new HTTP response of the specified statusCode.

Throws:

IllegalArgumentException - if the specified statusCode is informational.

of

static HttpResponse of(HttpStatus status)

Creates a new HTTP response of the specified HttpStatus.

Throws:

IllegalArgumentException - if the specified HttpStatus is informational.

of

static HttpResponse of(HttpStatus status,
 MediaType mediaType,
 CharSequence content)

Creates a new HTTP response of the specified HttpStatus.

Parameters:

mediaType - the MediaType of the response content

content - the content of the response

Throws:

IllegalArgumentException - if the specified HttpStatus is informational.

of

static HttpResponse of(HttpStatus status,
 MediaType mediaType,
 String content)

Creates a new HTTP response of the specified HttpStatus.

Parameters:

mediaType - the MediaType of the response content

content - the content of the response

Throws:

IllegalArgumentException - if the specified HttpStatus is informational.

of

static HttpResponse of(String content)

Creates a new HTTP response of OK status with the content as UTF_8.

Parameters:

content - the content of the response

of

@FormatMethod
static HttpResponse of(@FormatString
 String format,
 Object... args)

Creates a new HTTP response of OK status with the content as UTF_8. The content of the response is formatted by String.format(Locale, String, Object...) with English locale.

Parameters:

format - the format string of the response content

args - the arguments referenced by the format specifiers in the format string

of

static HttpResponse of(MediaType mediaType,
 String content)

Creates a new HTTP response of OK status with the content.

Parameters:

mediaType - the MediaType of the response content

content - the content of the response

of

@FormatMethod
static HttpResponse of(MediaType mediaType,
 @FormatString
 String format,
 Object... args)

Creates a new HTTP response of OK status with the content. The content of the response is formatted by String.format(Locale, String, Object...) with English locale.

Parameters:

mediaType - the MediaType of the response content

format - the format string of the response content

args - the arguments referenced by the format specifiers in the format string

of

@FormatMethod
static HttpResponse of(HttpStatus status,
 MediaType mediaType,
 @FormatString
 String format,
 Object... args)

Creates a new HTTP response of the specified HttpStatus. The content of the response is formatted by String.format(Locale, String, Object...) with English locale.

Parameters:

mediaType - the MediaType of the response content

format - the format string of the response content

args - the arguments referenced by the format specifiers in the format string

Throws:

IllegalArgumentException - if the specified HttpStatus is informational.

of

static HttpResponse of(HttpStatus status,
 MediaType mediaType,
 byte[] content)

Creates a new HTTP response of the specified HttpStatus. The content will be wrapped using HttpData.wrap(byte[]), so any changes made to content will be reflected in the response.

Parameters:

mediaType - the MediaType of the response content

content - the content of the response

Throws:

IllegalArgumentException - if the specified HttpStatus is informational.

of

static HttpResponse of(HttpStatus status,
 MediaType mediaType,
 HttpData content)

Creates a new HTTP response of the specified HttpStatus.

Parameters:

mediaType - the MediaType of the response content

content - the content of the response

Throws:

IllegalArgumentException - if the specified HttpStatus is informational.

of

static HttpResponse of(HttpStatus status,
 MediaType mediaType,
 HttpData content,
 HttpHeaders trailers)

Creates a new HTTP response of the specified HttpStatus.

Parameters:

mediaType - the MediaType of the response content

content - the content of the response

trailers - the HTTP trailers

Throws:

IllegalArgumentException - if the specified HttpStatus is informational.

of

static HttpResponse of(ResponseHeaders headers)

Creates a new HTTP response of the specified headers.

Throws:

IllegalArgumentException - if the status of the specified ResponseHeaders is informational.

of

static HttpResponse of(ResponseHeaders headers,
 HttpData content)

Creates a new HTTP response of the specified headers and content.

Throws:

IllegalArgumentException - if the status of the specified ResponseHeaders is informational.

of

static HttpResponse of(ResponseHeaders headers,
 HttpData content,
 HttpHeaders trailers)

Creates a new HTTP response of the specified objects.

Throws:

IllegalArgumentException - if the status of the specified ResponseHeaders is informational.

of

static HttpResponse of(HttpObject... objs)

Creates a new HTTP response of the specified objects.

of

static HttpResponse of(org.reactivestreams.Publisher<? extends HttpObject> publisher)

Creates a new HTTP response whose stream is produced from an existing Publisher.

Note that the HttpObjects in the Publisher are not released when Subscription.cancel() or StreamMessage.abort() is called. You should add a hook in order to release the elements. See PublisherBasedStreamMessage for more information.

of

static HttpResponse of(ResponseHeaders headers,
 org.reactivestreams.Publisher<? extends HttpObject> publisher)

Creates a new HTTP response with the specified headers whose stream is produced from an existing Publisher.

Note that the HttpObjects in the Publisher are not released when Subscription.cancel() or StreamMessage.abort() is called. You should add a hook in order to release the elements. See PublisherBasedStreamMessage for more information.

ofJson

static HttpResponse ofJson(Object content)

Creates a new HTTP response with the specified content that is converted into JSON using the default ObjectMapper.

Throws:

IllegalArgumentException - if failed to encode the content into JSON.

See Also:

JacksonObjectMapperProvider

ofJson

static HttpResponse ofJson(HttpStatus status,
 Object content)

Creates a new HTTP response with the specified HttpStatus and content that is converted into JSON using the default ObjectMapper.

Throws:

IllegalArgumentException - if failed to encode the content into JSON.

See Also:

JacksonObjectMapperProvider

ofJson

static HttpResponse ofJson(MediaType contentType,
 Object content)

Creates a new HTTP response with the specified MediaType and content that is converted into JSON using the default ObjectMapper.

Throws:

IllegalArgumentException - if the specified MediaType is not a JSON compatible type; or if failed to encode the content into JSON.

See Also:

JacksonObjectMapperProvider

ofJson

static HttpResponse ofJson(HttpStatus status,
 MediaType contentType,
 Object content)

Creates a new HTTP response with the specified HttpStatus, MediaType and content that is converted into JSON using the default ObjectMapper.

Throws:

IllegalArgumentException - if the specified MediaType is not a JSON compatible type; or if failed to encode the content into JSON.

See Also:

JacksonObjectMapperProvider

ofJson

static HttpResponse ofJson(ResponseHeaders headers,
 Object content)

Creates a new HTTP response with the specified ResponseHeaders and content that is converted into JSON using the default ObjectMapper.

Throws:

IllegalArgumentException - if failed to encode the content into JSON.

See Also:

JacksonObjectMapperProvider

ofRedirect

static HttpResponse ofRedirect(HttpStatus redirectStatus,
 String location)

Creates a new HTTP response of the redirect to specific location.

ofRedirect

static HttpResponse ofRedirect(HttpStatus redirectStatus,
 String format,
 Object... args)

Creates a new HTTP response of the redirect to specific location using string format.

ofRedirect

static HttpResponse ofRedirect(String location)

Creates a new HTTP response of the temporary redirect to specific location.

ofRedirect

static HttpResponse ofRedirect(String format,
 Object... args)

Creates a new HTTP response of the temporary redirect to specific location using string format.

ofFailure

static HttpResponse ofFailure(Throwable cause)

Creates a new failed HTTP response.

whenComplete

CompletableFuture<Void> whenComplete()

Description copied from interface: Response

Returns a CompletableFuture which completes when 1) the response stream has been closed (the StreamMessage has been completed) or 2) the result value is set (the CompletionStage has completed.)

Specified by:

whenComplete in interface Response

Specified by:

whenComplete in interface StreamMessage<HttpObject>

aggregate

default CompletableFuture<AggregatedHttpResponse> aggregate()

Aggregates this response. The returned CompletableFuture will be notified when the content and the trailers of the response are received fully.

aggregate

default CompletableFuture<AggregatedHttpResponse> aggregate(EventExecutor executor)

Aggregates this response. The returned CompletableFuture will be notified when the content and the trailers of the response are received fully.

aggregateWithPooledObjects

@UnstableApi
default CompletableFuture<AggregatedHttpResponse> aggregateWithPooledObjects(ByteBufAllocator alloc)

(Advanced users only) Aggregates this response. The returned CompletableFuture will be notified when the content and the trailers of the response are received fully. AggregatedHttpObject.content() will return a pooled object, and the caller must ensure to release it. If you don't know what this means, use aggregate().

See Also:

PooledObjects

aggregateWithPooledObjects

default CompletableFuture<AggregatedHttpResponse> aggregateWithPooledObjects(EventExecutor executor,
 ByteBufAllocator alloc)

Aggregates this response. The returned CompletableFuture will be notified when the content and the trailers of the request is received fully. AggregatedHttpObject.content() will return a pooled object, and the caller must ensure to release it. If you don't know what this means, use aggregate().

toDuplicator

default HttpResponseDuplicator toDuplicator()

Description copied from interface: StreamMessage

Returns a new StreamMessageDuplicator that duplicates this StreamMessage into one or more StreamMessages, which publish the same elements. Note that you cannot subscribe to this StreamMessage anymore after you call this method. To subscribe, call StreamMessageDuplicator.duplicate() from the returned StreamMessageDuplicator.

Specified by:

toDuplicator in interface StreamMessage<HttpObject>

toDuplicator

default HttpResponseDuplicator toDuplicator(EventExecutor executor)

Description copied from interface: StreamMessage

Returns a new StreamMessageDuplicator that duplicates this StreamMessage into one or more StreamMessages, which publish the same elements. Note that you cannot subscribe to this StreamMessage anymore after you call this method. To subscribe, call StreamMessageDuplicator.duplicate() from the returned StreamMessageDuplicator.

Specified by:

toDuplicator in interface StreamMessage<HttpObject>

Parameters:

executor - the executor to duplicate

toDuplicator

default HttpResponseDuplicator toDuplicator(long maxResponseLength)

Description copied from interface: HttpMessage

Returns a new StreamMessageDuplicator that duplicates this HttpMessage into one or more HttpMessages, which publish the same elements. Note that you cannot subscribe to this HttpMessage anymore after you call this method. To subscribe, call StreamMessageDuplicator.duplicate() from the returned StreamMessageDuplicator.

Specified by:

toDuplicator in interface HttpMessage

Parameters:

maxResponseLength - the maximum content length that the duplicator can hold in its buffer. ContentTooLargeException is raised if the length of the buffered HttpData is greater than this value.

toDuplicator

default HttpResponseDuplicator toDuplicator(EventExecutor executor,
 long maxResponseLength)

Description copied from interface: HttpMessage

Returns a new StreamMessageDuplicator that duplicates this HttpMessage into one or more HttpMessages, which publish the same elements. Note that you cannot subscribe to this HttpMessage anymore after you call this method. To subscribe, call StreamMessageDuplicator.duplicate() from the returned StreamMessageDuplicator.

Specified by:

toDuplicator in interface HttpMessage

Parameters:

executor - the executor to duplicate

maxResponseLength - the maximum content length that the duplicator can hold in its buffer. ContentTooLargeException is raised if the length of the buffered HttpData is greater than this value.

split

@CheckReturnValue
default SplitHttpResponse split()

Returns a new SplitHttpResponse which splits a stream of HttpObjects into HttpHeaders and HttpData. SplitHttpResponse.headers() will be completed before publishing the first HttpData. SplitHttpResponse.trailers() might not complete until the entire response body is consumed completely.

split

@CheckReturnValue
default SplitHttpResponse split(EventExecutor executor)

Returns a new SplitHttpResponse which splits a stream of HttpObjects into HttpHeaders and HttpData. SplitHttpResponse.headers() will be completed before publishing the first HttpData. SplitHttpResponse.trailers() might not complete until the entire response body is consumed completely.

decode

default <T> StreamMessage<T> decode(HttpDecoder<T> decoder,
 ByteBufAllocator alloc,
 Function<? super HttpData,? extends ByteBuf> byteBufConverter)

Description copied from interface: HttpMessage

Creates a decoded StreamMessage which is decoded from a stream of HttpObjects using the specified HttpDecoder and ByteBufAllocator and byteBufConverter.

Specified by:

decode in interface HttpMessage

mapInformational

default HttpResponse mapInformational(Function<? super ResponseHeaders,? extends ResponseHeaders> function)

Transforms the informational headers emitted by HttpResponse by applying the specified Function.

mapHeaders

default HttpResponse mapHeaders(Function<? super ResponseHeaders,? extends ResponseHeaders> function)

Transforms the non-informational ResponseHeaders emitted by HttpResponse by applying the specified Function.

For example:

 HttpResponse response = HttpResponse.of("OK");
 HttpResponse transformed = response.mapHeaders(headers -> {
     return headers.withMutations(builder -> {
         builder.set(HttpHeaderNames.USER_AGENT, "my-server");
     });
 });
 assert transformed.aggregate().join().headers()
                   .get(HttpHeaderNames.USER_AGENT).equals("my-server");
 

mapData

default HttpResponse mapData(Function<? super HttpData,? extends HttpData> function)

Transforms the HttpDatas emitted by this HttpRequest by applying the specified Function.

For example:

 HttpResponse response = HttpResponse.of("data1,data2");
 HttpResponse transformed = response.mapData(data -> {
     return HttpData.ofUtf8(data.toStringUtf8().replaceAll(",", "\n"));
 });
 assert transformed.aggregate().join().contentUtf8().equals("data1\ndata2");
 

mapTrailers

default HttpResponse mapTrailers(Function<? super HttpHeaders,? extends HttpHeaders> function)

Transforms the trailers emitted by this HttpResponse by applying the specified Function.

For example:

 HttpResponse response = HttpResponse.of("data");
 HttpResponse transformed = response.mapTrailers(trailers -> {
     return trailers.withMutations(builder -> builder.add("trailer1", "foo"));
 });
 assert transformed.aggregate().join().trailers().get("trailer1").equals("foo");
 

mapError

default HttpResponse mapError(Function<? super Throwable,? extends Throwable> function)

Transforms an error emitted by this HttpResponse by applying the specified Function.

For example:

 HttpResponse response = HttpResponse.ofFailure(new IllegalStateException("Something went wrong.");
 HttpResponse transformed = response.mapError(cause -> {
     if (cause instanceof IllegalStateException) {
         return new MyDomainException(cause);
     } else {
         return cause;
     }
 });
 

Specified by:

mapError in interface StreamMessage<HttpObject>

recover

default HttpResponse recover(Function<? super Throwable,? extends HttpResponse> function)

Recovers a failed HttpResponse by switching to a returned fallback HttpResponse when any error occurs before a ResponseHeaders is written. Note that the failed HttpResponse cannot be recovered from an error if a ResponseHeaders was written already.

Example:

 HttpResponse response = HttpResponse.ofFailure(new IllegalStateException("Oops..."));
 // The failed HttpResponse will be recovered by the fallback function.
 HttpResponse recovered = response.recover(cause -> HttpResponse.of("Fallback"));
 assert recovered.aggregate().join().contentUtf8().equals("Fallback");

 // As HTTP headers and body were written already before an error occurred,
 // the fallback function could not be applied for the failed HttpResponse.
 HttpResponseWriter response = HttpResponse.streaming();
 response.write(ResponseHeaders.of(HttpStatus.OK));
 response.write(HttpData.ofUtf8("Hello"));
 response.close(new IllegalStateException("Oops..."));
 HttpResponse notRecovered = response.recover(cause -> HttpResponse.of("Fallback"));
 // The IllegalStateException will be raised even though a fallback function was added.
 notRecovered.aggregate().join();