Hi there!
I have an error (see full stack below), when I’m trying to open Vaadin page in my project. Other servlets works ok. I used maven to make this project, and I thinking something wrong with my pom.xml, becouse when I make project in eclipse (with same sources), it works fine.
java.lang.NullPointerException
at com.google.appengine.api.NamespaceManager.get(NamespaceManager.java:109)
at com.google.appengine.api.memcache.MemcacheServiceImpl.getEffectiveNamespace(MemcacheServiceImpl.java:247)
at com.google.appengine.api.memcache.MemcacheServiceImpl.doPut(MemcacheServiceImpl.java:384)
at com.google.appengine.api.memcache.MemcacheServiceImpl.put(MemcacheServiceImpl.java:443)
at com.vaadin.terminal.gwt.server.GAEApplicationServlet.service(GAEApplicationServlet.java:216)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:362)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:726)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:405)
at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:206)
at org.mortbay.jetty.handler.HandlerCollection.handle(HandlerCollection.java:114)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:324)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:505)
at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:829)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:514)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:211)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:380)
at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:395)
at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:488)Here is my pom.xml
pom.xml
and web.xml
web.xml
appengine-web.xml
<?xml version="1.0" encoding="utf-8"?>
<appengine-web-app xmlns="http://appengine.google.com/ns/1.0">
<application></application>
<version>1</version>
<sessions-enabled>true</sessions-enabled>
<!-- Configure java.util.logging -->
<system-properties>
<property name="java.util.logging.config.file" value="WEB-INF/logging.properties"/>
</system-properties>
</appengine-web-app>If anyone has working pom.xml for Vaadin+GAE project, I would be glad if you share it with me. I’ve spend two days to make it works, but with any success 
Many thanks!
Gregory