Java tutorial
/* * 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.esigate.servlet; import java.io.IOException; import javax.servlet.Filter; import javax.servlet.FilterChain; import javax.servlet.FilterConfig; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.http.client.methods.CloseableHttpResponse; import org.esigate.DriverFactory; import org.esigate.HttpErrorPage; import org.esigate.http.IncomingRequest; import org.esigate.servlet.impl.RequestFactory; import org.esigate.servlet.impl.ResponseSender; /** * {@link Filter} that can mix local and distant contents using EsiGate. * * @author Francois-Xavier Bonnet * */ public class ProxyFilter implements Filter { private RequestFactory requestFactory; private final ResponseSender responseSender = new ResponseSender(); @Override public void init(FilterConfig filterConfig) { requestFactory = new RequestFactory(filterConfig.getServletContext()); // Force esigate configuration parsing to trigger errors right away (if // any) and prevent delay on first call. DriverFactory.ensureConfigured(); } @Override public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException { HttpServletRequest httpServletRequest = (HttpServletRequest) request; HttpServletResponse httpServletResponse = (HttpServletResponse) response; IncomingRequest incomingRequest = requestFactory.create(httpServletRequest, httpServletResponse, chain); try { CloseableHttpResponse driverResponse = DriverFactory.proxy(incomingRequest); responseSender.sendResponse(driverResponse, incomingRequest, httpServletResponse); } catch (HttpErrorPage e) { if (!httpServletResponse.isCommitted()) { responseSender.sendResponse(e.getHttpResponse(), incomingRequest, httpServletResponse); } } } @Override public void destroy() { // Nothing to do } }