Package org.apache.druid.java.util.http.client.response

Interface HttpResponseHandler<IntermediateType,​FinalType>

  • All Known Implementing Classes:
    BytesFullResponseHandler, FrameFileHttpResponseHandler, InputStreamFullResponseHandler, InputStreamResponseHandler, ObjectOrErrorResponseHandler, SequenceInputStreamResponseHandler, StatusResponseHandler, StringFullResponseHandler
    public interface HttpResponseHandler<IntermediateType,​FinalType>
    A handler for an HTTP request. The ClientResponse object passed around is used to store state between further chunks and indicate when it is safe to hand the object back to the caller. If the response is chunked, the ClientResponse object returned from handleResponse will be passed in as the first argument to handleChunk(). If the ClientResponse object is marked as finished, that indicates that the object stored is safe to hand off to the caller. This is most often done either from the done() method after all content has been processed or from the initial handleResponse method to indicate that the object is thread-safe and aware that it might be accessed before all chunks come back. Note: if you return a finished ClientResponse object from anything other than the done() method, IntermediateType must be castable to FinalType This handler can exert backpressure by returning a response with "continueReading" set to false from handleResponse() or handleChunk(). In this case, the HTTP client will stop reading soon thereafter. It may not happen immediately, so be prepared for more handleChunk() calls to happen. To resume reads, call resume() on the TrafficCop provided by handleResponse() with a chunk number at least as high as the one provided by the handleChunk() call from which you returned a suspend-reading response. If you are resuming reads after suspending them from handleResponse(), use 0 for the chunk number.

    • Method Detail

      • handleResponse

        ClientResponse<IntermediateType> handleResponse​(org.jboss.netty.handler.codec.http.HttpResponse response,
                                                HttpResponseHandler.TrafficCop trafficCop)
        Handles the initial HttpResponse object that comes back from Netty.
        Parameters:
        response - response from Netty
        trafficCop - flow controller, allows resuming suspended reads
        Returns:
        response that may be "finished" or "unfinished".

      • handleChunk

        ClientResponse<IntermediateType> handleChunk​(ClientResponse<IntermediateType> clientResponse,
                                             org.jboss.netty.handler.codec.http.HttpChunk chunk,
                                             long chunkNum)
        Called for chunked responses, indicating another HttpChunk has arrived.
        Parameters:
        clientResponse - last response returned by the prior handleResponse() or handleChunk()
        chunk - the new chunk of data
        chunkNum - the sequence number of this chunk (increases monotonically)
        Returns:
        response that may be "finished" or "unfinished".

      • done

        ClientResponse<FinalType> done​(ClientResponse<IntermediateType> clientResponse)
        Called after the final handleResponse() or handleChunk() call, signifying that no more data will arrive.
        Parameters:
        clientResponse - last response returned by handleResponse() or handleChunk()
        Returns:
        response containing an object to hand back to the caller. It must be a "finished" response.