/*
* eXist Open Source Native XML Database Copyright (C) 2001-2005, Wolfgang M.
* Meier (meier@ifs.tu-darmstadt.de)
*
* This library is free software; you can redistribute it and/or modify it under
* the terms of the GNU Library General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option) any
* later version.
*
* This library 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. See the GNU Library General Public License for more
* details.
*
* You should have received a copy of the GNU Library General Public License
* along with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* $Id$
*/
package org.exist.util;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;
import java.util.zip.ZipOutputStream;
import org.apache.commons.io.output.ByteArrayOutputStream;
public class Compressor {
/**
* The method <code>compress</code>
*
* @param whatToCompress a <code>byte[]</code> value
* @return a <code>byte[]</code> value
* @exception IOException if an error occurs
*/
public static byte[] compress(byte[] whatToCompress) throws IOException {
return compress(whatToCompress, whatToCompress.length);
}
/**
* The method <code>compress</code>
*
* @param whatToCompress a <code>byte[]</code> value
* @param length an <code>int</code> value
* @return a <code>byte[]</code> value
* @exception IOException if an error occurs
*/
public static byte[] compress(byte[] whatToCompress, int length) throws IOException {
final ByteArrayOutputStream baos = new ByteArrayOutputStream();
final ZipOutputStream gzos = new ZipOutputStream(baos);
gzos.setMethod(ZipOutputStream.DEFLATED);
gzos.putNextEntry(new ZipEntry(length + ""));
gzos.write(whatToCompress, 0, length);
gzos.closeEntry();
gzos.finish();
gzos.close();
return baos.toByteArray();
}
/**
* The method <code>uncompress</code>
*
* @param whatToUncompress a <code>byte[]</code> value
* @return a <code>byte[]</code> value
* @exception IOException if an error occurs
*/
public static byte[] uncompress(byte[] whatToUncompress)
throws IOException {
final ByteArrayOutputStream baos = new ByteArrayOutputStream();
uncompress(whatToUncompress, baos);
return baos.toByteArray();
}
public static void uncompress(byte[] whatToUncompress, OutputStream os)
throws IOException {
final ByteArrayInputStream bais = new ByteArrayInputStream(whatToUncompress);
final ZipInputStream gzis = new ZipInputStream(bais);
final ZipEntry zipentry = gzis.getNextEntry();
Integer.parseInt(zipentry.getName());
final byte[] buf = new byte[512];
int bread;
while ((bread = gzis.read(buf)) != -1)
os.write(buf, 0, bread);
gzis.closeEntry();
gzis.close();
}
}