crisp.wbwiki.server
Class WikiServiceImpl

java.lang.Object
  javax.servlet.GenericServlet
      javax.servlet.http.HttpServlet
          com.google.gwt.user.server.rpc.RemoteServiceServlet
              crisp.wbwiki.server.WikiServiceImpl

All Implemented Interfaces:

com.google.gwt.user.client.rpc.RemoteService, WikiService, Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig

public class WikiServiceImpl
extends com.google.gwt.user.server.rpc.RemoteServiceServlet
implements WikiService

Servlet that receives http requests from Whiteboard Wiki via AJAX. GWT handles the HTTP requests (in superclass RemoteServiceServlet) and translates them into simple RPC method calls on WikiServiceImpl.

Persistence logic is delegated to a WikiDb. This servlet requires a spring application context, which it uses to look up the WikiDb instance. Usually this means you should have a /WEB-INF/applicationContext.xml. For details see:

• http://www.springframework.org/docs/api/org/springframework/web/context/support/WebApplicationContextUtils.html
• http://www.springframework.org/docs/api/org/springframework/web/context/ContextLoader.html

Author:

Henrik Kniberg

See Also:

Serialized Form

Constructor Summary

WikiServiceImpl()

WikiServiceImpl(WikiDb wikiDb)

Method Summary

protected WikiDb	getWikiDb()
void	init()
protected void	setWikiDb(WikiDb wikiDb)
Page	synchronize(Integer lastVersionLoadedByClient, String modifiedContentInClient) Synchronizes the state between client and server.

Methods inherited from class com.google.gwt.user.server.rpc.RemoteServiceServlet

doPost, getThreadLocalRequest, getThreadLocalResponse, onAfterResponseSerialized, onBeforeRequestDeserialized, processCall, shouldCompressResponse

Methods inherited from class javax.servlet.http.HttpServlet

doDelete, doGet, doHead, doOptions, doPut, doTrace, getLastModified, service, service

Methods inherited from class javax.servlet.GenericServlet

destroy, getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, getServletName, init, log, log

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

WikiServiceImpl

public WikiServiceImpl()

WikiServiceImpl

public WikiServiceImpl(WikiDb wikiDb)

Method Detail

init

public void init()
          throws javax.servlet.ServletException

Overrides:

init in class javax.servlet.GenericServlet

Throws:

javax.servlet.ServletException

getWikiDb

protected WikiDb getWikiDb()

setWikiDb

protected void setWikiDb(WikiDb wikiDb)

synchronize

public Page synchronize(Integer lastVersionLoadedByClient,
                        String modifiedContentInClient)

Description copied from interface: WikiService

Synchronizes the state between client and server. More specifically, saves the given new content (if any) to the server and returns an up-to-date Page if necessary.

If the currently saved version of the page is the same as lastVersionLoadedByClient, then null is returned since the client's version is up-to-date already. In that case, if modifiedContentInClient is not null the client should increment his lastVersionLoadedByClient, effectively "pretending" that it has received an updated from the server.

If the currently saved version of the page is NOT the same as lastVersionLoadedByClient, some interference has occurred. Probably someone else has edited the page concurrently. In that case a new, up-to-date Page object will be returned to the client.

Specified by:

synchronize in interface WikiService

Parameters:

lastVersionLoadedByClient - ¨ which version the client last loaded from the server, or null if nothing has been loaded yet.

modifiedContentInClient - which content to save, or null if nothing has been changed in the client. in the client since lastVersionLoadedByClient

Returns:

an up-to-date Page object or null if the client is already up-to-date.