CompressedHttpClient.java

/*********************************************************************************
 *  TotalCross Software Development Kit                                          *
 *  Copyright (C) 2000-2012 SuperWaba Ltda.                                      *
 *  All Rights Reserved                                                          *
 *                                                                               *
 *  This library and virtual machine is distributed in the hope that it will     *
 *  be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of    *
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.                         *
 *                                                                               *
 *  This file is covered by the GNU LESSER GENERAL PUBLIC LICENSE VERSION 3.0    *
 *  A copy of this license is located in file license.txt at the root of this    *
 *  SDK or can be downloaded here:                                               *
 *  http://www.gnu.org/licenses/lgpl-3.0.txt                                     *
 *                                                                               *
 *********************************************************************************/

package totalcross.xml.rpc;

import totalcross.io.ByteArrayStream;
import totalcross.io.IOException;
import totalcross.net.UnknownHostException;
import totalcross.sys.Convert;
import totalcross.sys.InvalidNumberException;
import totalcross.util.zip.ZLib;

/**
 * @author pvanhout
 */
public class CompressedHttpClient extends StandardHttpClient
{
   private static ByteArrayStream out = new ByteArrayStream(65500);

   /**
    * See the constructor for the StandardHttpClient
    */
   public CompressedHttpClient(String hostname, int port, String uri, int openTimeout, int readTimeout, int writeTimeout) throws XmlRpcException, UnknownHostException
   {
      super(hostname, port, uri, openTimeout, readTimeout, writeTimeout);
   }

   public CompressedHttpClient(String hostname, int port, String uri) throws XmlRpcException, UnknownHostException
   {
      super(hostname, port, uri);
   }

   private Object readCompressedResponse(boolean asBytes) throws XmlRpcException, IOException
   {
      String v;
      int contentLength=0;
      if ((v=(String)htHeader.get("content-length")) != null)
         try
         {
            contentLength = Convert.toInt(v);
         }
         catch (InvalidNumberException ine)
         {
            throw new XmlRpcException("Invalid response from server - No Content");
         }

      byte[] contentBuff = new byte[contentLength];
      int contentRead = reader.readBytes(contentBuff, 0, contentLength);
      if (contentRead != contentLength)
         throw new XmlRpcException("Could not read answer: "+contentRead+" is less than "+contentLength);
      ByteArrayStream is = new ByteArrayStream(contentBuff);
      ByteArrayStream os = out;
      os.reset();
      int inflateSize = ZLib.inflate(is, os);
      return asBytes ? (Object)os.toByteArray() : new String(os.getBuffer(), 0, inflateSize);
   }

   /**
    * Executes a HTTP request to the connected server
    *
    * @param requestBody
    *           The contents of the HTTP request. Headers are added
    *           appropriately by this method after the request is compressed
    * @throws XmlRpcException
    *            If the server returns a status code other than 200 OK
    */
   public String execute(byte[] requestBody) throws XmlRpcException
   {
      return (String)privateExecute(requestBody, false);
   }
   
   /**
    * Executes a HTTP request to the connected server
    *
    * @param requestBody
    *           The contents of the HTTP request. Headers are added
    *           appropriately by this method after the request is compressed
    * @throws XmlRpcException
    *            If the server returns a status code other than 200 OK
    */
   public byte[] executeReturnBytes(byte[] requestBody) throws XmlRpcException
   {
      return (byte[])privateExecute(requestBody, true);
   }
      
   private Object privateExecute(byte[] requestBody, boolean asBytes) throws XmlRpcException
   {
      try
      {
         // compress the body
         ByteArrayStream is = new ByteArrayStream(requestBody);
         ByteArrayStream os = out;
         out.reset();
         int compressedSize = ZLib.deflate(is, os, ZLib.BEST_COMPRESSION);

         // send to the server
         writeRequest(os.getBuffer(), compressedSize);
         checkResponse();
         parseHeader();

         // read the answer
         boolean inflateResults = "deflate".equals(htHeader.get("content-encoding"));
         return inflateResults ? readCompressedResponse(asBytes) : asBytes ? readResponseBytes() : readResponse();
      }
      catch (IOException e)
      {
         throw new XmlRpcException(e.getMessage());
      }
   }

   /** Writes the headers for a HTTP request, adding the deflate method as content-encoding.  */
   protected StringBuffer writeRequestHeader(int requestLength)
   {
      StringBuffer requestHeader = super.writeRequestHeader(requestLength);
      requestHeader.append("Content-Encoding: deflate\r\n"); // append our specific header
      return requestHeader;
   }
}