package org.apache.jcs.utils.zip;
   
   /*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF 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.
   */
  
  import java.io.ByteArrayInputStream;
  import java.io.ByteArrayOutputStream;
  import java.io.IOException;
  import java.util.zip.DataFormatException;
  import java.util.zip.Deflater;
  import java.util.zip.GZIPInputStream;
  import java.util.zip.Inflater;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  
  /** Compress / Decompress. */
  public final class CompressionUtil
  {
      /** The logger */
      private final static Log log = LogFactory.getLog( CompressionUtil.class );
  
      /**
       * no instances.
       */
      private CompressionUtil()
      {
          // NO OP
      }
  
      /**
       * Decompress the byte array passed using a default buffer length of 1024.
       * <p>
       * @param input compressed byte array webservice response
       * @return uncompressed byte array
       */
      public static byte[] decompressByteArray( final byte[] input )
      {
          return decompressByteArray( input, 1024 );
      }
  
      /**
       * Decompress the byte array passed
       * <p>
       * @param input compressed byte array webservice response
       * @param bufferLength buffer length
       * @return uncompressed byte array
       */
      public static byte[] decompressByteArray( final byte[] input, final int bufferLength )
      {
          if ( null == input )
          {
              throw new IllegalArgumentException( "Input was null" );
          }
  
          // Create the decompressor and give it the data to compress
          final Inflater decompressor = new Inflater();
  
          decompressor.setInput( input );
  
          // Create an expandable byte array to hold the decompressed data
          final ByteArrayOutputStream baos = new ByteArrayOutputStream( input.length );
  
          // Decompress the data
          final byte[] buf = new byte[bufferLength];
  
          try
          {
              while ( !decompressor.finished() )
              {
                  int count = decompressor.inflate( buf );
                  baos.write( buf, 0, count );
              }
          }
          catch ( DataFormatException ex )
          {
              log.error( "Problem decompressing.", ex );
          }
  
          try
          {
              baos.close();
          }
         catch ( IOException ex )
         {
             log.error( "Problem closing stream.", ex );
         }
 
         return baos.toByteArray();
     }
 
     /**
      * Compress the byte array passed
      * <p>
      * @param input byte array
      * @return compressed byte array
      * @exception IOException thrown if we can't close the output stream
      */
     public static byte[] compressByteArray( byte[] input )
         throws IOException
     {
         return compressByteArray( input, 1024 );
     }
 
     /**
      * Compress the byte array passed
      * <p>
      * @param input byte array
      * @param bufferLength buffer length
      * @return compressed byte array
      * @exception IOException thrown if we can't close the output stream
      */
     public static byte[] compressByteArray( byte[] input, int bufferLength )
         throws IOException
     {
         // Compressor with highest level of compression
         Deflater compressor = new Deflater();
         compressor.setLevel( Deflater.BEST_COMPRESSION );
 
         // Give the compressor the data to compress
         compressor.setInput( input );
         compressor.finish();
 
         // Create an expandable byte array to hold the compressed data.
         // It is not necessary that the compressed data will be smaller than
         // the uncompressed data.
         ByteArrayOutputStream bos = new ByteArrayOutputStream( input.length );
 
         // Compress the data
         byte[] buf = new byte[bufferLength];
         while ( !compressor.finished() )
         {
             int count = compressor.deflate( buf );
             bos.write( buf, 0, count );
         }
 
         bos.close();
 
         // Get the compressed data
         return bos.toByteArray();
 
     }
 
     /**
      * decompress a gzip byte array, using a default buffer length of 1024
      * <p>
      * @param compressedByteArray gzip-compressed byte array
      * @return decompressed byte array
      * @throws IOException thrown if there was a failure to construct the GzipInputStream
      */
     public static byte[] decompressGzipByteArray( byte[] compressedByteArray )
         throws IOException
     {
         return decompressGzipByteArray( compressedByteArray, 1024 );
     }
 
     /**
      * decompress a gzip byte array, using a default buffer length of 1024
      * <p>
      * @param compressedByteArray gzip-compressed byte array
      * @param bufferlength size of the buffer in bytes
      * @return decompressed byte array
      * @throws IOException thrown if there was a failure to construct the GzipInputStream
      */
     public static byte[] decompressGzipByteArray( byte[] compressedByteArray, int bufferlength )
         throws IOException
     {
         ByteArrayOutputStream uncompressedStream = new ByteArrayOutputStream();
 
         GZIPInputStream compressedStream = new GZIPInputStream( new ByteArrayInputStream( compressedByteArray ) );
 
         byte[] buffer = new byte[bufferlength];
 
         int index = -1;
 
         while ( ( index = compressedStream.read( buffer ) ) != -1 )
         {
             uncompressedStream.write( buffer, 0, index );
         }
 
         return uncompressedStream.toByteArray();
     }
 }