/*
* Copyright 2002-2007 the original author or authors.
*
* Licensed 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.
*/
package org.internna.iwebmvc.core.jee.gzip;
import java.io.IOException;
import java.util.HashSet;
import java.util.Set;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.internna.iwebmvc.utils.StringUtils;
/**
* A servlet filter that compresses the response contents.
*
* @author Jayson Falkner [http://www.jspbook.com/]
* @author Jose Noheda
*/
public class GZIPFilter implements Filter {
protected final String GZIPPED_RESPONSE = "gzip";
private Set<String> excludedURLs = new HashSet<String>();
protected boolean excludedPath(String pathInfo) {
boolean excluded = false;
if (pathInfo != null)
for (String exclude : excludedURLs)
excluded |= pathInfo.contains(exclude);
return excluded;
}
public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
boolean uncompressed = true;
if (req instanceof HttpServletRequest) {
HttpServletRequest request = (HttpServletRequest) req;
if (request.getAttribute(GZIPPED_RESPONSE) == null) {
request.setAttribute(GZIPPED_RESPONSE, true);
HttpServletResponse response = (HttpServletResponse) res;
String ae = request.getHeader("accept-encoding");
String pathInfo = request.getPathInfo();
if ((ae != null) && (ae.indexOf("gzip") != -1) && (!GZIPResponseWrapper.class.isInstance(res))) {
if (!excludedPath(pathInfo)) {
uncompressed = false;
GZIPResponseWrapper wrappedResponse = new GZIPResponseWrapper(response);
chain.doFilter(req, wrappedResponse);
wrappedResponse.finishResponse();
}
}
}
}
if (uncompressed) chain.doFilter(req, res);
}
public void init(FilterConfig filterConfig) {
String exclude = filterConfig.getInitParameter("excluded-urls");
if (StringUtils.hasText(exclude))
for (String url : exclude.split(","))
excludedURLs.add(url.trim());
}
public void destroy() {
excludedURLs.clear();
return;
}
}