org.mortbay.proxy.AsyncProxy Maven / Gradle / Ivy
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//========================================================================
//Copyright 2006 Mort Bay Consulting Pty. 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.mortbay.proxy;
import java.io.IOException;
import java.net.URL;
import java.util.Random;
import java.util.concurrent.ConcurrentMap;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.mortbay.io.Buffer;
import org.mortbay.jetty.HttpMethods;
import org.mortbay.jetty.RetryRequest;
import org.mortbay.jetty.Server;
import org.mortbay.jetty.client.HttpClient;
import org.mortbay.jetty.client.HttpExchange;
import org.mortbay.jetty.nio.SelectChannelConnector;
import org.mortbay.jetty.servlet.Context;
import org.mortbay.jetty.servlet.ServletHolder;
import org.mortbay.thread.QueuedThreadPool;
import org.mortbay.thread.ThreadPool;
import org.mortbay.util.ajax.Continuation;
import org.mortbay.util.ajax.ContinuationSupport;
/* ------------------------------------------------------------ */
/** Ebay proxy servlet.
*
* Can be used as servlet or directly as a main.
* @author gregw
*
*/
public class AsyncProxy extends HttpServlet
{
static final long serialVersionUID = 1L;
private String _remoteUrl;
private HttpClient _client=new HttpClient();
private ServletContext _context;
public static void main(String[] args)
throws Exception
{
Server server = new Server();
SelectChannelConnector connector = new SelectChannelConnector();
connector.setPort(8090);
connector.setAcceptors(4);
connector.setHeaderBufferSize(4096);
connector.setRequestBufferSize(8182);
connector.setResponseBufferSize(32768);
server.addConnector(connector);
QueuedThreadPool threadpool = new QueuedThreadPool();
threadpool.setMinThreads(20);
threadpool.setMaxThreads(50);
threadpool.setMaxIdleTimeMs(60000);
server.setThreadPool(threadpool);
Context context = new Context(server,"/",Context.SESSIONS);
ServletHolder servlet=new ServletHolder(new AsyncProxy());
servlet.setInitParameter("remoteUrl","http://localhost:8080/test/dump");
context.addServlet(servlet, "/*");
context.setAttribute("threadpool",threadpool);
server.start();
server.join();
}
public void init() throws ServletException
{
try
{
_context = getServletConfig().getServletContext();
_remoteUrl = getServletConfig().getInitParameter("remoteUrl");
if (_remoteUrl==null)
_remoteUrl="http://localhost:8080/test/dump";
ThreadPool threadpool = (ThreadPool)_context.getAttribute("threadpool");
if (threadpool==null)
{
QueuedThreadPool qthreadpool = new QueuedThreadPool();
qthreadpool.setMinThreads(20);
qthreadpool.setMaxThreads(50);
qthreadpool.setMaxIdleTimeMs(60000);
threadpool=qthreadpool;
}
_client.setThreadPool(threadpool);
_client.setConnectorType(HttpClient.CONNECTOR_SELECT_CHANNEL);
_client.setMaxConnectionsPerAddress(10000); // needed as all go to same address!
_client.setHeaderBufferSize(4096);
_client.setRequestBufferSize(8182);
_client.setResponseBufferSize(32768);
_client.start();
}
catch (Exception e)
{
throw new ServletException(e);
}
}
@Override
protected void doGet(HttpServletRequest req, final HttpServletResponse response)
throws ServletException, IOException
{
final Continuation continuation = ContinuationSupport.getContinuation(req, null);
if (!continuation.isPending())
{
final String sessionId = req.getSession(true).getId();
System.out.println("");
System.out.println("Session id: " + sessionId + " ");
if (req.getParameter("remoteUrl") != null)
{
_remoteUrl = req.getParameter("remoteUrl");
_context.log("Changed remoteUrl: "+_remoteUrl);
}
String remoteUri = req.getParameter("remoteUri");
if (remoteUri == null)
remoteUri = "/remoteApp/page";
String url = _remoteUrl + remoteUri;
String latencyStr = req.getParameter("latency");
int latency = latencyStr == null ? 240 : Integer.parseInt(latencyStr);
// If the file being served has other URIs in it, like say images,
// subsequent calls are made to the remote app to retrieve those.
// We don't want to set new delay times and status codes then.
if (remoteUri.endsWith("page"))
{
Integer[] params = generateRandomParams(latency);
url+="?sessionId="+sessionId+
"&delay="+params[0]+
"&code="+params[1];
System.out.println(url);
}
else
{
System.out.println(url);
}
// Create the HTTP exchange as an anonymous object
HttpExchange exchange = new HttpExchange()
{
long _start=System.currentTimeMillis();
ServletOutputStream _out;
/* ------------------------------------------------------------ */
protected void onException(Throwable ex)
{
try
{
System.out.println(" Exception to " + sessionId + " in " + (System.currentTimeMillis() - _start));
response.sendError(500);
continuation.resume();
}
catch(Exception e)
{
_context.log("exception",e);
}
}
/* ------------------------------------------------------------ */
protected void onExpire()
{
try
{
System.out.println(" Timeout for " + sessionId + " in " + (System.currentTimeMillis() - _start));
response.sendError(500);
continuation.resume();
}
catch(Exception e)
{
_context.log("exception",e);
}
}
/* ------------------------------------------------------------ */
protected void onResponseContent(Buffer content) throws IOException
{
byte[] array = content.array();
if(array!=null)
_out.write(array,content.getIndex(),content.length());
else
_out.write(content.asArray()); // TODO consider avoiding this extra buffer!
}
/* ------------------------------------------------------------ */
protected void onResponseHeaderComplete() throws IOException
{
_out=response.getOutputStream();
}
/* ------------------------------------------------------------ */
protected void onResponseHeader(Buffer name, Buffer value) throws IOException
{
response.setHeader(name.toString(),value.toString());
}
/* ------------------------------------------------------------ */
protected void onResponseStatus(Buffer version, int status, Buffer reason) throws IOException
{
response.setStatus(status,reason.toString());
System.out.println(" onResponse() - Status:" + status + " - " + " " + sessionId);
}
/* ------------------------------------------------------------ */
protected void onResponseComplete() throws IOException
{
System.out.println(" Responded to " + sessionId + " in " + (System.currentTimeMillis() - _start));
continuation.resume();
}
};
exchange.setMethod(HttpMethods.GET);
exchange.setURL(url);
try
{
_client.send(exchange);
continuation.suspend(100*1000);
}
catch (RetryRequest r)
{
throw r;
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
/* ------------------------------------------------------------ */
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException
{
doGet(req, resp);
}
/* ------------------------------------------------------------ */
public static Integer[] generateRandomParams(int latency)
{
Integer[] params = new Integer[2];
final int[] codes = new int[] { 200, 302, 403, 404, 500};
Random generator = new Random();
// generate a random delay between 10ms and 10 + latency ms
int delay = generator.nextInt(latency) + 10;
params[0] = new Integer(delay);
// generate randomly one of http status codes.
int index = generator.nextInt(codes.length);
params[1] = new Integer(codes[index]);
return params;
}
}
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