在java中实现tar,gzip功能

在将文件归档时，通常将文件压缩，而程序一般部署在web application 上的，在程序里部署一段程序，就可以实现用JAVA 压缩归档。

/**
 * Compress (tar.gz) the input file (or directory) to the output file
 * 

 *
 * In the case of a directory all files within the directory (and all nested
 * directories) will be added to the archive
 *
 * @param file The file(s if a directory) to compress
 * @param output The resulting output file (should end in .tar.gz)
 * @throws IOException
 */
public static void compressFile(File file, File output)
	throws IOException
{
	ArrayList list = new ArrayList(1);
	list.add(file);
	compressFiles(list, output);
}

/**
 * Compress (tar.gz) the input files to the output file
 *
 * @param files The files to compress
 * @param output The resulting output file (should end in .tar.gz)
 * @throws IOException
 */
public static void compressFiles(Collection files, File output)
	throws IOException
{
	LOG.debug("Compressing "+files.size() + " to "+output.getAbsoluteFile());
               // Create the output stream for the output file
	FileOutputStream fos = new FileOutputStream(output);
               // Wrap the output file stream in streams that will tar and gzip everything
	TarArchiveOutputStream taos = new TarArchiveOutputStream(
		new GZIPOutputStream(new BufferedOutputStream(fos)));
               // TAR has an 8 gig file limit by default, this gets around that
	taos.setBigNumberMode(TarArchiveOutputStream.BIGNUMBER_STAR); // to get past the 8 gig limit
               // TAR originally didn't support long file names, so enable the support for it
	taos.setLongFileMode(TarArchiveOutputStream.LONGFILE_GNU);

               // Get to putting all the files in the compressed output file
	for (File f : files) {
		addFilesToCompression(taos, f, ".");
	}

               // Close everything up
	taos.close();
	fos.close();
}

/**
 * Does the work of compression and going recursive for nested directories
 * 

 *
 * Borrowed heavily from http://www.thoughtspark.org/node/53
 *
 * @param taos The archive
 * @param file The file to add to the archive
        * @param dir The directory that should serve as the parent directory in the archivew
 * @throws IOException
 */
private static void addFilesToCompression(TarArchiveOutputStream taos, File file, String dir)
	throws IOException
{
               // Create an entry for the file
	taos.putArchiveEntry(new TarArchiveEntry(file, dir+FILE_SEPARATOR+file.getName()));
	if (file.isFile()) {
                       // Add the file to the archive
		BufferedInputStream bis = new BufferedInputStream(new FileInputStream(file));
		IOUtils.copy(bis, taos);
		taos.closeArchiveEntry();
		bis.close();
	}
	else if (file.isDirectory()) {
                       // close the archive entry
		taos.closeArchiveEntry();
                       // go through all the files in the directory and using recursion, add them to the archive
		for (File childFile : file.listFiles()) {
			addFilesToCompression(taos, childFile, file.getName());
		}
	}
}

From：一号门