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   /*
    * Copyright 2012 The Netty Project
    *
    * The Netty Project licenses this file to you under the Apache License,
    * version 2.0 (the "License"); you may not use this file except in compliance
    * with the License. You may obtain a copy of the License at:
    *
    *   http://www.apache.org/licenses/LICENSE-2.0
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
   * License for the specific language governing permissions and limitations
   * under the License.
   */
  package org.jboss.netty.handler.codec.http;
  
  import org.jboss.netty.buffer.ChannelBuffer;
  import org.jboss.netty.channel.ChannelPipeline;
  import org.jboss.netty.handler.codec.frame.TooLongFrameException;
  
  
  /**
   * Decodes {@link ChannelBuffer}s into {@link HttpResponse}s and
   * {@link HttpChunk}s.
   *
   * <h3>Parameters that prevents excessive memory consumption</h3>
   * <table border="1">
   * <tr>
   * <th>Name</th><th>Meaning</th>
   * </tr>
   * <tr>
   * <td>{@code maxInitialLineLength}</td>
   * <td>The maximum length of the initial line (e.g. {@code "HTTP/1.0 200 OK"})
   *     If the length of the initial line exceeds this value, a
   *     {@link TooLongFrameException} will be raised.</td>
   * </tr>
   * <tr>
   * <td>{@code maxHeaderSize}</td>
   * <td>The maximum length of all headers.  If the sum of the length of each
   *     header exceeds this value, a {@link TooLongFrameException} will be raised.</td>
   * </tr>
   * <tr>
   * <td>{@code maxChunkSize}</td>
   * <td>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
   *     {@link HttpChunk}s.  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
   *     {@link HttpChunk}s in your handler, insert {@link HttpChunkAggregator}
   *     after this decoder in the {@link ChannelPipeline}.</td>
   * </tr>
   * </table>
   *
   * <h3>Decoding a response for a <tt>HEAD</tt> request</h3>
   * <p>
   * Unlike other HTTP requests, the successful response of a <tt>HEAD</tt>
   * request does not have any content even if there is <tt>Content-Length</tt>
   * header.  Because {@link HttpResponseDecoder} is not able to determine if the
   * response currently being decoded is associated with a <tt>HEAD</tt> request,
   * you must override {@link #isContentAlwaysEmpty(HttpMessage)} to return
   * <tt>true</tt> for the response of the <tt>HEAD</tt> request.
   * </p><p>
   * If you are writing an HTTP client that issues a <tt>HEAD</tt> request,
   * please use {@link HttpClientCodec} instead of this decoder.  It will perform
   * additional state management to handle the responses for <tt>HEAD</tt>
   * requests correctly.
   * </p>
   *
   * <h3>Decoding a response for a <tt>CONNECT</tt> request</h3>
   * <p>
   * You also need to do additional state management to handle the response of a
   * <tt>CONNECT</tt> request properly, like you did for <tt>HEAD</tt>.  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.
   * </p><p>
   * {@link HttpClientCodec} also handles this edge case correctly, so you have to
   * use {@link HttpClientCodec} if you are writing an HTTP client that issues a
   * <tt>CONNECT</tt> request.
   * </p>
   */
  public class HttpResponseDecoder extends HttpMessageDecoder {
  
      /**
       * Creates a new instance with the default
       * {@code maxInitialLineLength (4096}}, {@code maxHeaderSize (8192)}, and
       * {@code maxChunkSize (8192)}.
       */
      public HttpResponseDecoder() {
      }
  
      /**
       * Creates a new instance with the specified parameters.
       */
      public HttpResponseDecoder(
              int maxInitialLineLength, int maxHeaderSize, int maxChunkSize) {
          super(maxInitialLineLength, maxHeaderSize, maxChunkSize);
     }
 
     @Override
     protected HttpMessage createMessage(String[] initialLine) {
         return new DefaultHttpResponse(
                 HttpVersion.valueOf(initialLine[0]),
                 new HttpResponseStatus(Integer.valueOf(initialLine[1]), initialLine[2]));
     }
 
     @Override
     protected boolean isDecodingRequest() {
         return false;
     }
 }