Package org.jboss.netty.handler.codec.http

Class HttpResponseDecoder

  • All Implemented Interfaces:
    ChannelHandler, ChannelUpstreamHandler, LifeCycleAwareChannelHandler
    Direct Known Subclasses:
    HttpClientCodec.Decoder
    public class HttpResponseDecoder
extends HttpMessageDecoder
    Decodes ChannelBuffers into HttpResponses and HttpChunks.

    Parameters that prevents excessive memory consumption

    NameMeaning
    maxInitialLineLength The maximum length of the initial line (e.g. "HTTP/1.0 200 OK") If the length of the initial line exceeds this value, a TooLongFrameException will be raised.
    maxHeaderSize The maximum length of all headers. If the sum of the length of each header exceeds this value, a TooLongFrameException will be raised.
    maxChunkSize The maximum length of the content or each chunk. If the content length exceeds this value, the transfer encoding of the decoded response will be converted to 'chunked' and the content will be split into multiple HttpChunks. If the transfer encoding of the HTTP response is 'chunked' already, each chunk will be split into smaller chunks if the length of the chunk exceeds this value. If you prefer not to handle HttpChunks in your handler, insert HttpChunkAggregator after this decoder in the ChannelPipeline.

    Decoding a response for a HEAD request

    Unlike other HTTP requests, the successful response of a HEAD request does not have any content even if there is Content-Length header. Because HttpResponseDecoder is not able to determine if the response currently being decoded is associated with a HEAD request, you must override HttpMessageDecoder.isContentAlwaysEmpty(HttpMessage) to return true for the response of the HEAD request.

    If you are writing an HTTP client that issues a HEAD request, please use HttpClientCodec instead of this decoder. It will perform additional state management to handle the responses for HEAD requests correctly.

    Decoding a response for a CONNECT request

    You also need to do additional state management to handle the response of a CONNECT request properly, like you did for HEAD. One difference is that the decoder should stop decoding completely after decoding the successful 200 response since the connection is not an HTTP connection anymore.

    HttpClientCodec also handles this edge case correctly, so you have to use HttpClientCodec if you are writing an HTTP client that issues a CONNECT request.

    • Constructor Detail

      • HttpResponseDecoder

        public HttpResponseDecoder()
        Creates a new instance with the default maxInitialLineLength (4096}, maxHeaderSize (8192), and maxChunkSize (8192).

      • HttpResponseDecoder

        public HttpResponseDecoder​(int maxInitialLineLength,
                           int maxHeaderSize,
                           int maxChunkSize)
        Creates a new instance with the specified parameters.