/**
*
* Copyright 2004 Protique Ltd
*
* 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.codehaus.activemq.transport.http;
import EDU.oswego.cs.dl.util.concurrent.BoundedLinkedQueue;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.codehaus.activemq.message.Packet;
import org.codehaus.activemq.message.TextWireFormat;
import org.codehaus.activemq.transport.TransportChannelListener;
import org.codehaus.activemq.util.JMSExceptionHelper;
import javax.jms.JMSException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
/**
* @version $Revision: 1.2 $
*/
public class HttpTunnelServlet extends HttpServlet {
private static final Log log = LogFactory.getLog(HttpTunnelServlet.class);
private TransportChannelListener listener;
private TextWireFormat wireFormat;
private Map clients = new HashMap();
private long requestTimeout = 30000L;
public void init() throws ServletException {
super.init();
listener = (TransportChannelListener) getServletContext().getAttribute("transportChannelListener");
if (listener == null) {
throw new ServletException("No such attribute 'transportChannelListener' available in the ServletContext");
}
wireFormat = (TextWireFormat) getServletContext().getAttribute("wireFormat");
if (wireFormat == null) {
throw new ServletException("No such attribute 'wireFormat' available in the ServletContext");
}
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// lets return the next response
Packet packet = null;
try {
HttpServerTransportChannel transportChannel = getTransportChannel(request);
if (transportChannel == null) {
return;
}
packet = (Packet) transportChannel.getChannel().poll(requestTimeout);
}
catch (InterruptedException e) {
// ignore
}
if (packet == null) {
response.setStatus(HttpServletResponse.SC_REQUEST_TIMEOUT);
}
else {
try {
wireFormat.writePacket(packet, new DataOutputStream(response.getOutputStream()));
}
catch (JMSException e) {
throw JMSExceptionHelper.newIOException(e);
}
}
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
HttpServerTransportChannel transportChannel = getTransportChannel(request);
if (transportChannel == null) {
response.setStatus(HttpServletResponse.SC_NOT_FOUND);
}
else {
try {
Packet packet = wireFormat.fromString(readRequestBody(request));
transportChannel.getPacketListener().consume(packet);
}
catch (IOException e) {
log.error("Caught: " + e, e);
}
catch (JMSException e) {
throw JMSExceptionHelper.newIOException(e);
}
}
}
protected String readRequestBody(HttpServletRequest request) throws IOException {
StringBuffer buffer = new StringBuffer();
BufferedReader reader = request.getReader();
while (true) {
String line = reader.readLine();
if (line == null) {
break;
}
else {
buffer.append(line);
buffer.append("\n");
}
}
return buffer.toString();
}
protected HttpServerTransportChannel getTransportChannel(HttpServletRequest request) {
String clientID = request.getHeader("clientID");
if (clientID == null) {
clientID = request.getParameter("clientID");
}
if (clientID == null) {
log.warn("No clientID header so ignoring request");
return null;
}
synchronized (this) {
HttpServerTransportChannel answer = (HttpServerTransportChannel) clients.get(clientID);
if (answer == null) {
answer = createTransportChannel();
clients.put(clientID, answer);
listener.addClient(answer);
}
else {
// this lookup should keep the client alive, otherwise we need to discard it
keepAlivePing(answer);
}
return answer;
}
}
/**
* Disable this channel from being auto-disconnected after a timeout period
*/
protected void keepAlivePing(HttpServerTransportChannel channel) {
/** TODO */
}
protected HttpServerTransportChannel createTransportChannel() {
return new HttpServerTransportChannel(new BoundedLinkedQueue(10));
}
}