001 /**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017 package org.apache.camel.component.jetty;
018
019 import java.io.IOException;
020 import javax.servlet.ServletException;
021 import javax.servlet.http.HttpServletRequest;
022 import javax.servlet.http.HttpServletResponse;
023
024 import org.apache.camel.AsyncCallback;
025 import org.apache.camel.Exchange;
026 import org.apache.camel.ExchangePattern;
027 import org.apache.camel.component.http.CamelServlet;
028 import org.apache.camel.component.http.HttpConsumer;
029 import org.apache.camel.component.http.HttpMessage;
030 import org.apache.camel.impl.DefaultExchange;
031 import org.eclipse.jetty.continuation.Continuation;
032 import org.eclipse.jetty.continuation.ContinuationSupport;
033
034 /**
035 * Currently not in use.
036 *
037 * @version $Revision: 19985 $
038 */
039 public class CamelContinuationServlet extends CamelServlet {
040
041 private static final long serialVersionUID = 1L;
042
043 @Override
044 protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
045 try {
046 // Is there a consumer registered for the request.
047 HttpConsumer consumer = resolve(request);
048 if (consumer == null) {
049 response.sendError(HttpServletResponse.SC_NOT_FOUND);
050 return;
051 }
052
053 // are we suspended?
054 if (consumer.isSuspended()) {
055 response.sendError(HttpServletResponse.SC_SERVICE_UNAVAILABLE);
056 return;
057 }
058
059 final Continuation continuation = ContinuationSupport.getContinuation(request);
060 if (continuation.isInitial()) {
061
062 // a new request so create an exchange
063 final Exchange exchange = new DefaultExchange(consumer.getEndpoint(), ExchangePattern.InOut);
064 if (consumer.getEndpoint().isBridgeEndpoint()) {
065 exchange.setProperty(Exchange.SKIP_GZIP_ENCODING, Boolean.TRUE);
066 }
067 if (consumer.getEndpoint().isDisableStreamCache()) {
068 exchange.setProperty(Exchange.DISABLE_HTTP_STREAM_CACHE, Boolean.TRUE);
069 }
070 exchange.setIn(new HttpMessage(exchange, request, response));
071
072 // use the asynchronous API to process the exchange
073 boolean sync = consumer.getAsyncProcessor().process(exchange, new AsyncCallback() {
074 public void done(boolean doneSync) {
075 // we only have to handle async completion
076 if (doneSync) {
077 return;
078 }
079
080 // we should resume the continuation now that we are done asynchronously
081 if (log.isTraceEnabled()) {
082 log.trace("Resuming continuation of exchangeId: " + exchange.getExchangeId());
083 }
084 continuation.setAttribute("CamelExchange", exchange);
085 continuation.resume();
086 }
087 });
088
089 if (!sync) {
090 // wait for the exchange to get processed.
091 // this might block until it completes or it might return via an exception and
092 // then this method is re-invoked once the the exchange has finished processing
093 if (log.isTraceEnabled()) {
094 log.trace("Suspending continuation of exchangeId: " + exchange.getExchangeId());
095 }
096 continuation.suspend(response);
097 return;
098 }
099
100 // now lets output to the response
101 if (log.isTraceEnabled()) {
102 log.trace("Writing response of exchangeId: " + exchange.getExchangeId());
103 }
104 consumer.getBinding().writeResponse(exchange, response);
105 return;
106 }
107
108 if (continuation.isResumed()) {
109 Exchange exchange = (Exchange) continuation.getAttribute("CamelExchange");
110 if (log.isTraceEnabled()) {
111 log.trace("Resuming continuation of exchangeId: " + exchange.getExchangeId());
112 }
113
114 // now lets output to the response
115 if (log.isTraceEnabled()) {
116 log.trace("Writing response of exchangeId: " + exchange.getExchangeId());
117 }
118 consumer.getBinding().writeResponse(exchange, response);
119 return;
120 }
121 } catch (Exception e) {
122 log.error("Error processing request", e);
123 throw new ServletException(e);
124 }
125 }
126
127 }