| package org.apache.commons.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 org.apache.commons.jcs.log.Log; |
| import org.apache.commons.jcs.log.LogManager; |
| |
| 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; |
| |
| /** Compress / Decompress. */ |
| public final class CompressionUtil |
| { |
| /** The logger */ |
| private static final Log log = LogManager.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 ); |
| } |
| |
| decompressor.end(); |
| |
| 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 |
| * @throws 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 |
| * @throws 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 ); |
| } |
| |
| // JCS-136 ( Details here : http://www.devguli.com/blog/eng/java-deflater-and-outofmemoryerror/ ) |
| compressor.end(); |
| 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(); |
| } |
| } |