// Copyright (c) 2000 Just Objects B.V. <just@justobjects.nl>// Distributable under LGPL license. See terms of license at gnu.org.package nl.justobjects.pushlet.core;import nl.justobjects.pushlet.util.PushletException;import nl.justobjects.pushlet.util.Servlets;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;/** * Wraps pushlet request/response data. * * @author Just van den Broecke - Just Objects &copy; * @version $Id: Command.java,v 1.4 2007/11/23 14:33:07 justb Exp $ */public class Command implements Protocol {	/**	 * Pushlet request event.	 */	public final Event reqEvent;	/**	 * Pushlet response  event.	 */	private Event rspEvent;	/**	 * HTTP Servlet GET/POST request.	 */	public final HttpServletRequest httpReq;	/**	 * HTTP Servlet GET/POST response.	 */	public final HttpServletResponse httpRsp;	/**	 * Pushlet session.	 */	public final Session session;	/**	 * Per-response client adapter.	 */	private ClientAdapter clientAdapter;	/**	 * Constructor.	 */	private Command(Session aSession, Event aRequestEvent, HttpServletRequest aHTTPReq, HttpServletResponse aHTTPRsp) {		session = aSession;		reqEvent = aRequestEvent;		httpReq = aHTTPReq;		httpRsp = aHTTPRsp;	}	/**	 * Create new Command object.	 */	public static Command create(Session aSession, Event aReqEvent, HttpServletRequest aHTTPReq, HttpServletResponse aHTTPRsp) {		return new Command(aSession, aReqEvent, aHTTPReq, aHTTPRsp);	}	/**	 * Set pushlet response event.	 */	public void setResponseEvent(Event aResponseEvent) {		rspEvent = aResponseEvent;	}	/**	 * Get pushlet response event.	 */	public Event getResponseEvent() {		return rspEvent;	}	/**	 * Get client adapter for request.	 */	public ClientAdapter getClientAdapter() throws PushletException {		if (clientAdapter == null) {			// Create and initialize client-specific adapter.			clientAdapter = createClientAdapter();		}		return clientAdapter;	}	/**	 * Create client notifier based on "format" parameter passed in request.	 */	protected ClientAdapter createClientAdapter() throws PushletException {		// Assumed to be set by parent.		String outputFormat = session.getFormat();		// Determine client adapter to create.		if (outputFormat.equals(FORMAT_JAVASCRIPT)) {			// Client expects to receive Events as JavaScript dispatch calls..			return new BrowserAdapter(httpRsp);		} else if (outputFormat.equals(FORMAT_SERIALIZED_JAVA_OBJECT)) {			// Client expects to receive Events as Serialized Java Objects.			return new SerializedAdapter(httpRsp);		} else if (outputFormat.equals(FORMAT_XML)) {			// Client expects to receive Events as stream of XML docs.			return new XMLAdapter(httpRsp);		} else if (outputFormat.equals(FORMAT_XML_STRICT)) {			// Client expects to receive Events embedded in single XML doc.			return new XMLAdapter(httpRsp, true);		} else {			throw new PushletException("Null or invalid output format: " + outputFormat);		}	}	/**	 * Sends HTTP response headers.	 */	protected void sendResponseHeaders() {		// Just to try to prevent caching in any form.		Servlets.setNoCacheHeaders(httpRsp);		// Close connection for Java enabled browsers		if (session.getUserAgent().indexOf("java") > 0) {			// The connection should be closed after this request			// NB: this allows sending a "long response". Some clients			// in particular java.net.URL in VMs > 1.1 that use HTTP/1.1			// will block if			// - the content length is not sent			// - if Connection: close HTTP header is not sent.			//			// Since we don't know the content length we will assume			// the underlying servlet engine will use chunked encoding.			httpRsp.setHeader("Connection", "close");		}	}}/*  * $Log: Command.java,v $  * Revision 1.4  2007/11/23 14:33:07  justb  * core classes now configurable through factory  *  * Revision 1.3  2005/05/06 19:44:00  justb  * added xml-strict format  *  * Revision 1.2  2005/02/28 17:25:15  justb  * commented  *  * Revision 1.1  2005/02/28 12:45:59  justb  * introduced Command class  *  *  */