@Override
	protected void processFilter(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws Exception {

		(...)

		StringServletResponse stringServletResponse = new StringServletResponse(response);
		Thread currentThread = Thread.currentThread();
		ClassLoader contextClassLoader = currentThread.getContextClassLoader();
		currentThread.setContextClassLoader(PortalClassLoaderUtil.getClassLoader());
		try {
			processFilter(OpenGraphFilter.class, request, stringServletResponse, filterChain);
		} finally {
			currentThread.setContextClassLoader(contextClassLoader);
		}
		String contentType = response.getContentType();
		String contentEncoding = stringServletResponse.getHeader(HttpHeaders.CONTENT_ENCODING);
		boolean isGZIP = ((contentEncoding != null)&&(contentEncoding.toLowerCase().equals("gzip")));
		if ((contentType != null)&&(contentType.startsWith(ContentTypes.TEXT_HTML))) {
			String content;
			if (isGZIP) {
				content = decompress(stringServletResponse.getUnsyncByteArrayOutputStream().toByteArray(), response.getCharacterEncoding());
			} else {
				content = stringServletResponse.getString();
			}
			content = getContent(request, content);
			if (isGZIP) {ServletResponseUtil.write(response, compress(content, response.getCharacterEncoding()));}
			else {ServletResponseUtil.write(response, content);}
		} else {
			ServletResponseUtil.write(response, stringServletResponse);
		}
		
	}

    public static byte[] compress(String str, String encoding) throws Exception {
		ByteArrayOutputStream baos = new ByteArrayOutputStream();
		GZIPOutputStream gos = new GZIPOutputStream(baos);
		gos.write(str.getBytes(encoding));
		gos.close();
		return baos.toByteArray();
    }

    public static String decompress(byte[] source, String encoding) throws Exception {
		GZIPInputStream gis = new GZIPInputStream(new ByteArrayInputStream(source));
		BufferedReader br = new BufferedReader(new InputStreamReader(gis, encoding));
		StringBuffer out = new StringBuffer();
		String line;
		while ((line = br.readLine()) != null) {out.append(line);}
		return out.toString();
    }