bundles/org.eclipse.rap.rwt/src/org/eclipse/rap/rwt/internal/service/LifeCycleServiceHandler.java - rap/org.eclipse.rap - Git at Google

 /*******************************************************************************
  * Copyright (c) 2002, 2015 Innoopract Informationssysteme GmbH and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  *    Innoopract Informationssysteme GmbH - initial API and implementation
  *    EclipseSource - ongoing development
  ******************************************************************************/
 package org.eclipse.rap.rwt.internal.service;

 import static javax.servlet.http.HttpServletResponse.SC_FORBIDDEN;
 import static javax.servlet.http.HttpServletResponse.SC_PRECONDITION_FAILED;
 import static org.eclipse.rap.rwt.internal.protocol.ClientMessageConst.RWT_INITIALIZE;
 import static org.eclipse.rap.rwt.internal.protocol.ClientMessageConst.SHUTDOWN;
 import static org.eclipse.rap.rwt.internal.service.ContextProvider.getContext;
 import static org.eclipse.rap.rwt.internal.service.ContextProvider.getServiceStore;
 import static org.eclipse.rap.rwt.internal.service.ContextProvider.getUISession;
 import static org.eclipse.rap.rwt.internal.util.HTTP.CHARSET_UTF_8;
 import static org.eclipse.rap.rwt.internal.util.HTTP.CONTENT_TYPE_JSON;
 import static org.eclipse.rap.rwt.internal.util.HTTP.METHOD_POST;

 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.io.Reader;

 import javax.servlet.ServletRequest;
 import javax.servlet.ServletResponse;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;

 import org.eclipse.rap.json.JsonObject;
 import org.eclipse.rap.json.JsonValue;
 import org.eclipse.rap.rwt.internal.lifecycle.RequestCounter;
 import org.eclipse.rap.rwt.internal.protocol.ClientMessage;
 import org.eclipse.rap.rwt.internal.protocol.ProtocolMessageWriter;
 import org.eclipse.rap.rwt.internal.protocol.ProtocolUtil;
 import org.eclipse.rap.rwt.internal.protocol.RequestMessage;
 import org.eclipse.rap.rwt.internal.protocol.ResponseMessage;
 import org.eclipse.rap.rwt.internal.remote.MessageChainReference;
 import org.eclipse.rap.rwt.internal.util.HTTP;
 import org.eclipse.rap.rwt.service.ServiceHandler;
 import org.eclipse.rap.rwt.service.UISession;


 public class LifeCycleServiceHandler implements ServiceHandler {

   private static final String PROP_ERROR = "error";
   private static final String PROP_REQUEST_COUNTER = "requestCounter";
   private static final String ATTR_LAST_RESPONSE_MESSAGE
     = LifeCycleServiceHandler.class.getName() + "#lastResponseMessage";
   private static final String ATTR_SESSION_STARTED
     = LifeCycleServiceHandler.class.getName() + "#isSessionStarted";

   private final MessageChainReference messageChainReference;
   private final StartupPage startupPage;

   public LifeCycleServiceHandler( MessageChainReference messageChainReference,
                                   StartupPage startupPage )
   {
     this.messageChainReference = messageChainReference;
     this.startupPage = startupPage;
   }

   public void service( HttpServletRequest request, HttpServletResponse response )
     throws IOException
   {
     // Do not use session store itself as a lock
     // see bug https://bugs.eclipse.org/bugs/show_bug.cgi?id=372946
     UISessionImpl uiSession = ( UISessionImpl )getUISession();
     synchronized( uiSession.getRequestLock() ) {
       synchronizedService( request, response );
     }
   }

   void synchronizedService( HttpServletRequest request, HttpServletResponse response )
     throws IOException
   {
     if( METHOD_POST.equals( request.getMethod() ) && isContentTypeValid( request ) ) {
       handleUIRequest( request, response );
     } else {
       handleStartupRequest( request, response );
     }
   }

   private void handleStartupRequest( HttpServletRequest request, HttpServletResponse response )
     throws IOException
   {
     try {
       sendStartupContent( request, response );
     } finally {
       // The GET request currently creates a dummy UI session needed for accessing the client
       // information. It is not meant to be reused by other requests.
       shutdownUISession();
     }
   }

   private void handleUIRequest( HttpServletRequest request, HttpServletResponse response )
     throws IOException
   {
     try {
       processUIRequest( request, response );
     } catch( IOException exception ) {
       shutdownUISession();
       throw exception;
     } catch( RuntimeException exception ) {
       shutdownUISession();
       throw exception;
     }
   }

   private void sendStartupContent( HttpServletRequest request, HttpServletResponse response )
     throws IOException
   {
     String accept = request.getHeader( HTTP.HEADER_ACCEPT );
     if( accept != null && accept.contains( HTTP.CONTENT_TYPE_JSON ) ) {
       StartupJson.send( response );
     } else {
       startupPage.send( response );
     }
   }

   private void processUIRequest( HttpServletRequest request, HttpServletResponse response )
     throws IOException
   {
     RequestMessage requestMessage = readRequestMessage( request );
     setJsonResponseHeaders( response );
     if( isSessionShutdown( requestMessage ) ) {
       shutdownUISession();
       writeEmptyMessage( response );
     } else if( isSessionTimeout( requestMessage ) ) {
       writeSessionTimeoutError( response );
     } else if( !isRequestCounterValid( requestMessage ) ) {
       if( isDuplicateRequest( requestMessage ) ) {
         writeBufferedResponse( response );
       } else {
         writeInvalidRequestCounterError( response );
       }
     } else {
       if( isSessionRestart( requestMessage ) ) {
         reinitializeUISession( request );
         reinitializeServiceStore();
       }
       UrlParameters.merge( requestMessage );
       ResponseMessage responseMessage = processMessage( requestMessage );
       writeResponseMessage( responseMessage, response );
       markSessionStarted();
     }
   }

   private RequestMessage readRequestMessage( HttpServletRequest request ) {
     try {
       return new ClientMessage( JsonObject.readFrom( getReader( request ) ) );
     } catch( IOException ioe ) {
       throw new IllegalStateException( "Unable to read the json message", ioe );
     }
   }

   /*
    * Workaround for bug in certain servlet containers where the reader is sometimes empty.
    * 411616: Application crash with very long messages
    * https://bugs.eclipse.org/bugs/show_bug.cgi?id=411616
    */
   private static Reader getReader( HttpServletRequest request ) throws IOException {
     String encoding = request.getCharacterEncoding();
     if( encoding == null ) {
       encoding = CHARSET_UTF_8;
     }
     return new InputStreamReader( request.getInputStream(), encoding );
   }

   private ResponseMessage processMessage( RequestMessage requestMessage ) {
     return messageChainReference.get().handleMessage( requestMessage );
   }

   private static boolean isRequestCounterValid( RequestMessage requestMessage ) {
     return hasInitializeParameter( requestMessage ) || hasValidRequestCounter( requestMessage );
   }

   static boolean hasValidRequestCounter( RequestMessage requestMessage ) {
     int currentRequestId = RequestCounter.getInstance().currentRequestId();
     JsonValue sentRequestId = requestMessage.getHead().get( PROP_REQUEST_COUNTER );
     if( sentRequestId == null ) {
       return currentRequestId == 0;
     }
     return currentRequestId == sentRequestId.asInt();
   }

   private static boolean isDuplicateRequest( RequestMessage requestMessage ) {
     int currentRequestId = RequestCounter.getInstance().currentRequestId();
     JsonValue sentRequestId = requestMessage.getHead().get( PROP_REQUEST_COUNTER );
     return sentRequestId != null && sentRequestId.asInt() == currentRequestId - 1;
   }

   private static boolean isContentTypeValid( ServletRequest request ) {
     String contentType = request.getContentType();
     return contentType != null && contentType.startsWith( CONTENT_TYPE_JSON );
   }

   private static void shutdownUISession() {
     UISessionImpl uiSession = ( UISessionImpl )getUISession();
     uiSession.shutdown();
   }

   private static void writeInvalidRequestCounterError( HttpServletResponse response )
     throws IOException
   {
     writeError( response, SC_PRECONDITION_FAILED, "invalid request counter" );
   }

   private static void writeSessionTimeoutError( HttpServletResponse response ) throws IOException {
     writeError( response, SC_FORBIDDEN, "session timeout" );
   }

   private static void writeError( HttpServletResponse response,
                                   int statusCode,
                                   String errorType ) throws IOException
   {
     response.setStatus( statusCode );
     ProtocolMessageWriter writer = new ProtocolMessageWriter();
     writer.appendHead( PROP_ERROR, JsonValue.valueOf( errorType ) );
     writer.createMessage().toJson().writeTo( response.getWriter() );
   }

   private static void reinitializeUISession( HttpServletRequest request ) {
     ServiceContext serviceContext = getContext();
     UISessionImpl uiSession = ( UISessionImpl )getUISession();
     uiSession.shutdown();
     UISessionBuilder builder = new UISessionBuilder( serviceContext );
     uiSession = builder.buildUISession();
     serviceContext.setUISession( uiSession );
   }

   private static void reinitializeServiceStore() {
     ClientMessage clientMessage = ProtocolUtil.getClientMessage();
     getServiceStore().clear();
     ProtocolUtil.setClientMessage( clientMessage );
   }

   /*
    * Session restart: we're in the same HttpSession and start over (e.g. by pressing F5)
    */
   private static boolean isSessionRestart( RequestMessage requestMessage ) {
     return isSessionStarted() && hasInitializeParameter( requestMessage );
   }

   private static boolean isSessionTimeout( RequestMessage message ) {
     // Session is not initialized because we got a new HTTPSession
     return !isSessionStarted() && !hasInitializeParameter( message );
   }

   static void markSessionStarted() {
     getUISession().setAttribute( ATTR_SESSION_STARTED, Boolean.TRUE );
   }

   private static boolean isSessionStarted() {
     return Boolean.TRUE.equals( getUISession().getAttribute( ATTR_SESSION_STARTED ) );
   }

   private static boolean isSessionShutdown( RequestMessage requestMessage ) {
     return JsonValue.TRUE.equals( requestMessage.getHead().get( SHUTDOWN ) );
   }

   private static boolean hasInitializeParameter( RequestMessage requestMessage ) {
     return JsonValue.TRUE.equals( requestMessage.getHead().get( RWT_INITIALIZE ) );
   }

   private static void setJsonResponseHeaders( ServletResponse response ) {
     response.setContentType( CONTENT_TYPE_JSON );
     response.setCharacterEncoding( CHARSET_UTF_8 );
   }

   private static void writeEmptyMessage( ServletResponse response ) throws IOException {
     new ProtocolMessageWriter().createMessage().toJson().writeTo( response.getWriter() );
   }

   private static void writeResponseMessage( ResponseMessage responseMessage,
                                             ServletResponse response )
     throws IOException
   {
     bufferMessage( responseMessage );
     responseMessage.toJson().writeTo( response.getWriter() );
   }

   private static void writeBufferedResponse( HttpServletResponse response ) throws IOException {
     getBufferedMessage().toJson().writeTo( response.getWriter() );
   }

   private static void bufferMessage( ResponseMessage responseMessage ) {
     UISession uiSession = getUISession();
     if( uiSession != null ) {
       uiSession.setAttribute( ATTR_LAST_RESPONSE_MESSAGE, responseMessage );
     }
   }

   private static ResponseMessage getBufferedMessage() {
     return ( ResponseMessage )getUISession().getAttribute( ATTR_LAST_RESPONSE_MESSAGE );
   }

 }
	/*******************************************************************************
	* Copyright (c) 2002, 2015 Innoopract Informationssysteme GmbH and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v1.0
	* which accompanies this distribution, and is available at
	* http://www.eclipse.org/legal/epl-v10.html
	*
	* Contributors:
	* Innoopract Informationssysteme GmbH - initial API and implementation
	* EclipseSource - ongoing development
	******************************************************************************/
	package org.eclipse.rap.rwt.internal.service;

	import static javax.servlet.http.HttpServletResponse.SC_FORBIDDEN;
	import static javax.servlet.http.HttpServletResponse.SC_PRECONDITION_FAILED;
	import static org.eclipse.rap.rwt.internal.protocol.ClientMessageConst.RWT_INITIALIZE;
	import static org.eclipse.rap.rwt.internal.protocol.ClientMessageConst.SHUTDOWN;
	import static org.eclipse.rap.rwt.internal.service.ContextProvider.getContext;
	import static org.eclipse.rap.rwt.internal.service.ContextProvider.getServiceStore;
	import static org.eclipse.rap.rwt.internal.service.ContextProvider.getUISession;
	import static org.eclipse.rap.rwt.internal.util.HTTP.CHARSET_UTF_8;
	import static org.eclipse.rap.rwt.internal.util.HTTP.CONTENT_TYPE_JSON;
	import static org.eclipse.rap.rwt.internal.util.HTTP.METHOD_POST;

	import java.io.IOException;
	import java.io.InputStreamReader;
	import java.io.Reader;

	import javax.servlet.ServletRequest;
	import javax.servlet.ServletResponse;
	import javax.servlet.http.HttpServletRequest;
	import javax.servlet.http.HttpServletResponse;

	import org.eclipse.rap.json.JsonObject;
	import org.eclipse.rap.json.JsonValue;
	import org.eclipse.rap.rwt.internal.lifecycle.RequestCounter;
	import org.eclipse.rap.rwt.internal.protocol.ClientMessage;
	import org.eclipse.rap.rwt.internal.protocol.ProtocolMessageWriter;
	import org.eclipse.rap.rwt.internal.protocol.ProtocolUtil;
	import org.eclipse.rap.rwt.internal.protocol.RequestMessage;
	import org.eclipse.rap.rwt.internal.protocol.ResponseMessage;
	import org.eclipse.rap.rwt.internal.remote.MessageChainReference;
	import org.eclipse.rap.rwt.internal.util.HTTP;
	import org.eclipse.rap.rwt.service.ServiceHandler;
	import org.eclipse.rap.rwt.service.UISession;


	public class LifeCycleServiceHandler implements ServiceHandler {

	private static final String PROP_ERROR = "error";
	private static final String PROP_REQUEST_COUNTER = "requestCounter";
	private static final String ATTR_LAST_RESPONSE_MESSAGE
	= LifeCycleServiceHandler.class.getName() + "#lastResponseMessage";
	private static final String ATTR_SESSION_STARTED
	= LifeCycleServiceHandler.class.getName() + "#isSessionStarted";

	private final MessageChainReference messageChainReference;
	private final StartupPage startupPage;

	public LifeCycleServiceHandler( MessageChainReference messageChainReference,
	StartupPage startupPage )
	{
	this.messageChainReference = messageChainReference;
	this.startupPage = startupPage;
	}

	public void service( HttpServletRequest request, HttpServletResponse response )
	throws IOException
	{
	// Do not use session store itself as a lock
	// see bug https://bugs.eclipse.org/bugs/show_bug.cgi?id=372946
	UISessionImpl uiSession = ( UISessionImpl )getUISession();
	synchronized( uiSession.getRequestLock() ) {
	synchronizedService( request, response );
	}
	}

	void synchronizedService( HttpServletRequest request, HttpServletResponse response )
	throws IOException
	{
	if( METHOD_POST.equals( request.getMethod() ) && isContentTypeValid( request ) ) {
	handleUIRequest( request, response );
	} else {
	handleStartupRequest( request, response );
	}
	}

	private void handleStartupRequest( HttpServletRequest request, HttpServletResponse response )
	throws IOException
	{
	try {
	sendStartupContent( request, response );
	} finally {
	// The GET request currently creates a dummy UI session needed for accessing the client
	// information. It is not meant to be reused by other requests.
	shutdownUISession();
	}
	}

	private void handleUIRequest( HttpServletRequest request, HttpServletResponse response )
	throws IOException
	{
	try {
	processUIRequest( request, response );
	} catch( IOException exception ) {
	shutdownUISession();
	throw exception;
	} catch( RuntimeException exception ) {
	shutdownUISession();
	throw exception;
	}
	}

	private void sendStartupContent( HttpServletRequest request, HttpServletResponse response )
	throws IOException
	{
	String accept = request.getHeader( HTTP.HEADER_ACCEPT );
	if( accept != null && accept.contains( HTTP.CONTENT_TYPE_JSON ) ) {
	StartupJson.send( response );
	} else {
	startupPage.send( response );
	}
	}

	private void processUIRequest( HttpServletRequest request, HttpServletResponse response )
	throws IOException
	{
	RequestMessage requestMessage = readRequestMessage( request );
	setJsonResponseHeaders( response );
	if( isSessionShutdown( requestMessage ) ) {
	shutdownUISession();
	writeEmptyMessage( response );
	} else if( isSessionTimeout( requestMessage ) ) {
	writeSessionTimeoutError( response );
	} else if( !isRequestCounterValid( requestMessage ) ) {
	if( isDuplicateRequest( requestMessage ) ) {
	writeBufferedResponse( response );
	} else {
	writeInvalidRequestCounterError( response );
	}
	} else {
	if( isSessionRestart( requestMessage ) ) {
	reinitializeUISession( request );
	reinitializeServiceStore();
	}
	UrlParameters.merge( requestMessage );
	ResponseMessage responseMessage = processMessage( requestMessage );
	writeResponseMessage( responseMessage, response );
	markSessionStarted();
	}
	}

	private RequestMessage readRequestMessage( HttpServletRequest request ) {
	try {
	return new ClientMessage( JsonObject.readFrom( getReader( request ) ) );
	} catch( IOException ioe ) {
	throw new IllegalStateException( "Unable to read the json message", ioe );
	}
	}

	/*
	* Workaround for bug in certain servlet containers where the reader is sometimes empty.
	* 411616: Application crash with very long messages
	* https://bugs.eclipse.org/bugs/show_bug.cgi?id=411616
	*/
	private static Reader getReader( HttpServletRequest request ) throws IOException {
	String encoding = request.getCharacterEncoding();
	if( encoding == null ) {
	encoding = CHARSET_UTF_8;
	}
	return new InputStreamReader( request.getInputStream(), encoding );
	}

	private ResponseMessage processMessage( RequestMessage requestMessage ) {
	return messageChainReference.get().handleMessage( requestMessage );
	}

	private static boolean isRequestCounterValid( RequestMessage requestMessage ) {
	return hasInitializeParameter( requestMessage ) \|\| hasValidRequestCounter( requestMessage );
	}

	static boolean hasValidRequestCounter( RequestMessage requestMessage ) {
	int currentRequestId = RequestCounter.getInstance().currentRequestId();
	JsonValue sentRequestId = requestMessage.getHead().get( PROP_REQUEST_COUNTER );
	if( sentRequestId == null ) {
	return currentRequestId == 0;
	}
	return currentRequestId == sentRequestId.asInt();
	}

	private static boolean isDuplicateRequest( RequestMessage requestMessage ) {
	int currentRequestId = RequestCounter.getInstance().currentRequestId();
	JsonValue sentRequestId = requestMessage.getHead().get( PROP_REQUEST_COUNTER );
	return sentRequestId != null && sentRequestId.asInt() == currentRequestId - 1;
	}

	private static boolean isContentTypeValid( ServletRequest request ) {
	String contentType = request.getContentType();
	return contentType != null && contentType.startsWith( CONTENT_TYPE_JSON );
	}

	private static void shutdownUISession() {
	UISessionImpl uiSession = ( UISessionImpl )getUISession();
	uiSession.shutdown();
	}

	private static void writeInvalidRequestCounterError( HttpServletResponse response )
	throws IOException
	{
	writeError( response, SC_PRECONDITION_FAILED, "invalid request counter" );
	}

	private static void writeSessionTimeoutError( HttpServletResponse response ) throws IOException {
	writeError( response, SC_FORBIDDEN, "session timeout" );
	}

	private static void writeError( HttpServletResponse response,
	int statusCode,
	String errorType ) throws IOException
	{
	response.setStatus( statusCode );
	ProtocolMessageWriter writer = new ProtocolMessageWriter();
	writer.appendHead( PROP_ERROR, JsonValue.valueOf( errorType ) );
	writer.createMessage().toJson().writeTo( response.getWriter() );
	}

	private static void reinitializeUISession( HttpServletRequest request ) {
	ServiceContext serviceContext = getContext();
	UISessionImpl uiSession = ( UISessionImpl )getUISession();
	uiSession.shutdown();
	UISessionBuilder builder = new UISessionBuilder( serviceContext );
	uiSession = builder.buildUISession();
	serviceContext.setUISession( uiSession );
	}

	private static void reinitializeServiceStore() {
	ClientMessage clientMessage = ProtocolUtil.getClientMessage();
	getServiceStore().clear();
	ProtocolUtil.setClientMessage( clientMessage );
	}

	/*
	* Session restart: we're in the same HttpSession and start over (e.g. by pressing F5)
	*/
	private static boolean isSessionRestart( RequestMessage requestMessage ) {
	return isSessionStarted() && hasInitializeParameter( requestMessage );
	}

	private static boolean isSessionTimeout( RequestMessage message ) {
	// Session is not initialized because we got a new HTTPSession
	return !isSessionStarted() && !hasInitializeParameter( message );
	}

	static void markSessionStarted() {
	getUISession().setAttribute( ATTR_SESSION_STARTED, Boolean.TRUE );
	}

	private static boolean isSessionStarted() {
	return Boolean.TRUE.equals( getUISession().getAttribute( ATTR_SESSION_STARTED ) );
	}

	private static boolean isSessionShutdown( RequestMessage requestMessage ) {
	return JsonValue.TRUE.equals( requestMessage.getHead().get( SHUTDOWN ) );
	}

	private static boolean hasInitializeParameter( RequestMessage requestMessage ) {
	return JsonValue.TRUE.equals( requestMessage.getHead().get( RWT_INITIALIZE ) );
	}

	private static void setJsonResponseHeaders( ServletResponse response ) {
	response.setContentType( CONTENT_TYPE_JSON );
	response.setCharacterEncoding( CHARSET_UTF_8 );
	}

	private static void writeEmptyMessage( ServletResponse response ) throws IOException {
	new ProtocolMessageWriter().createMessage().toJson().writeTo( response.getWriter() );
	}

	private static void writeResponseMessage( ResponseMessage responseMessage,
	ServletResponse response )
	throws IOException
	{
	bufferMessage( responseMessage );
	responseMessage.toJson().writeTo( response.getWriter() );
	}

	private static void writeBufferedResponse( HttpServletResponse response ) throws IOException {
	getBufferedMessage().toJson().writeTo( response.getWriter() );
	}

	private static void bufferMessage( ResponseMessage responseMessage ) {
	UISession uiSession = getUISession();
	if( uiSession != null ) {
	uiSession.setAttribute( ATTR_LAST_RESPONSE_MESSAGE, responseMessage );
	}
	}

	private static ResponseMessage getBufferedMessage() {
	return ( ResponseMessage )getUISession().getAttribute( ATTR_LAST_RESPONSE_MESSAGE );
	}

	}