private static void addDir(File dirFile, ZipOutputStream out, String prefix) throws IOException {
		File[] files = dirFile.listFiles();
		
		for (int i = 0; i < files.length; i++) {
			
			if (files[i].isDirectory()) {
				addDir(files[i], out, prefix);
				continue;
			}
			
			FileInputStream in = new FileInputStream(files[i].getAbsolutePath());
			
			String absolutePath = files[i].getAbsolutePath();
			String path = absolutePath.replaceFirst(prefix, "");		
			out.putNextEntry(new ZipEntry(path));
			
			int len;
			byte[] tmpBuf = new byte[1024];
			while ((len = in.read(tmpBuf)) > 0) {
				out.write(tmpBuf, 0, len);
			}
			
			out.closeEntry();
			in.close();
		}
	}