SocketIOServlet.java

/**
 * The MIT License
 * Copyright (c) 2010 Tad Glines
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package com.glines.socketio.server;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.HashMap;
import java.util.Map;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.eclipse.jetty.util.IO;

import com.glines.socketio.server.transport.FlashSocketTransport;
import com.glines.socketio.server.transport.HTMLFileTransport;
import com.glines.socketio.server.transport.JSONPPollingTransport;
import com.glines.socketio.server.transport.WebSocketTransport;
import com.glines.socketio.server.transport.XHRMultipartTransport;
import com.glines.socketio.server.transport.XHRPollingTransport;

/**
 */
public abstract class SocketIOServlet extends HttpServlet {
	public static final String BUFFER_SIZE_INIT_PARAM = "bufferSize";
	public static final String MAX_IDLE_TIME_INIT_PARAM = "maxIdleTime";
	public static final int BUFFER_SIZE_DEFAULT = 8192;
	public static final int MAX_IDLE_TIME_DEFAULT = 300*1000;
	private static final long serialVersionUID = 1L;
	private SocketIOSessionManager sessionManager = null;
	private Map<String, Transport> transports = new HashMap<String, Transport>();

	@Override
	public void init() throws ServletException {
		super.init();
		String str = this.getInitParameter(BUFFER_SIZE_INIT_PARAM);
		int bufferSize = str==null ? BUFFER_SIZE_DEFAULT : Integer.parseInt(str);
		str = this.getInitParameter(MAX_IDLE_TIME_INIT_PARAM);
		int maxIdleTime = str==null ? MAX_IDLE_TIME_DEFAULT : Integer.parseInt(str);

		sessionManager = new SocketIOSessionManager();
		WebSocketTransport websocketTransport = new WebSocketTransport(bufferSize, maxIdleTime);
		FlashSocketTransport flashsocketTransport = new FlashSocketTransport(bufferSize, maxIdleTime);
		HTMLFileTransport htmlFileTransport = new HTMLFileTransport(bufferSize, maxIdleTime);
		XHRMultipartTransport xhrMultipartTransport = new XHRMultipartTransport(bufferSize, maxIdleTime);
		XHRPollingTransport xhrPollingTransport = new XHRPollingTransport(bufferSize, maxIdleTime);
		JSONPPollingTransport jsonpPollingTransport = new JSONPPollingTransport(bufferSize, maxIdleTime);
		transports.put(websocketTransport.getName(), websocketTransport);
		transports.put(flashsocketTransport.getName(), flashsocketTransport);
		transports.put(htmlFileTransport.getName(), htmlFileTransport);
		transports.put(xhrMultipartTransport.getName(), xhrMultipartTransport);
		transports.put(xhrPollingTransport.getName(), xhrPollingTransport);
		transports.put(jsonpPollingTransport.getName(), jsonpPollingTransport);
		
		for (Transport t: transports.values()) {
			t.init(this.getServletConfig());
		}
	}

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        serve(req, resp);
    }

	@Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        serve(req, resp);
	}

    private void serve(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    	String path = request.getPathInfo();
    	if (path == null || path.length() == 0 || "/".equals(path)) {
    		response.sendError(HttpServletResponse.SC_BAD_REQUEST, "Missing SocketIO transport");
    		return;
    	}
    	if (path.startsWith("/")) path = path.substring(1);
    	String[] parts = path.split("/");

    	Transport transport = transports.get(parts[0]);
    	if (transport == null) {
    		if ("GET".equals(request.getMethod()) && "socket.io.js".equals(parts[0])) {
				response.setContentType("text/javascript");
				InputStream is = this.getClass().getClassLoader().getResourceAsStream("com/glines/socketio/socket.io.js");
				OutputStream os = response.getOutputStream();
				IO.copy(is, os);
				return;
    		} else {
	    		response.sendError(HttpServletResponse.SC_BAD_REQUEST, "Unknown SocketIO transport");
	    		return;
    		}
    	}

  		transport.handle(request, response, new Transport.InboundFactory() {

			@Override
			public SocketIOInbound getInbound(HttpServletRequest request) {
				return SocketIOServlet.this.doSocketIOConnect(request);
			}
  			
  		}, sessionManager);
    }

    @Override
    public void destroy() {
    	for (Transport t: transports.values()) {
    		t.destroy();
    	}
    	super.destroy();
    }

    /**
     * Returns an instance of SocketIOInbound or null if the connection is to be denied.
     * The value of cookies and protocols may be null.
     */
	protected abstract SocketIOInbound doSocketIOConnect(HttpServletRequest request);
}