Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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.apache.camel.component.http; import java.io.IOException; import java.util.concurrent.ConcurrentHashMap; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.camel.Exchange; import org.apache.camel.ExchangePattern; import org.apache.camel.component.http.helper.HttpHelper; import org.apache.camel.impl.DefaultExchange; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /** * @version $Revision$ */ public class CamelServlet extends HttpServlet { private static final long serialVersionUID = -7061982839117697829L; protected final transient Log log = LogFactory.getLog(getClass()); private ConcurrentHashMap<String, HttpConsumer> consumers = new ConcurrentHashMap<String, HttpConsumer>(); @Override protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { if (log.isTraceEnabled()) { log.trace("Service: " + request); } // Is there a consumer registered for the request. HttpConsumer consumer = resolve(request); if (consumer == null) { response.sendError(HttpServletResponse.SC_NOT_FOUND); return; } // are we suspended? if (consumer.isSuspended()) { response.sendError(HttpServletResponse.SC_SERVICE_UNAVAILABLE); return; } // create exchange and set data on it Exchange exchange = new DefaultExchange(consumer.getEndpoint(), ExchangePattern.InOut); if (consumer.getEndpoint().isBridgeEndpoint()) { exchange.setProperty(Exchange.SKIP_GZIP_ENCODING, Boolean.TRUE); } if (consumer.getEndpoint().isDisableStreamCache()) { exchange.setProperty(Exchange.DISABLE_HTTP_STREAM_CACHE, Boolean.TRUE); } HttpHelper.setCharsetFromContentType(request.getContentType(), exchange); exchange.setIn(new HttpMessage(exchange, request, response)); try { if (log.isTraceEnabled()) { log.trace("Processing request for exchangeId: " + exchange.getExchangeId()); } // process the exchange consumer.getProcessor().process(exchange); } catch (Exception e) { exchange.setException(e); } try { if (log.isTraceEnabled()) { log.trace("Writing response for exchangeId: " + exchange.getExchangeId()); } // now lets output to the response consumer.getBinding().writeResponse(exchange, response); } catch (IOException e) { log.error("Error processing request", e); throw e; } catch (Exception e) { log.error("Error processing request", e); throw new ServletException(e); } } protected HttpConsumer resolve(HttpServletRequest request) { String path = request.getPathInfo(); if (path == null) { return null; } HttpConsumer answer = consumers.get(path); if (answer == null) { for (String key : consumers.keySet()) { if (consumers.get(key).getEndpoint().isMatchOnUriPrefix() && path.startsWith(key)) { answer = consumers.get(key); break; } } } return answer; } public void connect(HttpConsumer consumer) { consumers.put(consumer.getPath(), consumer); } public void disconnect(HttpConsumer consumer) { consumers.remove(consumer.getPath()); } }