GWTP CrawlService OfyFactory is Null

Question

I am trying to use GWTP CrawlerService to make my GWTP app crawlable by search engines. I followed the wiki instructions to set it up.

When accessing the crawl service with the correct key and URL arguments I get a NullPointer exception on line 121 of ObjectifyDao.java beecause ofyFactory is null.

However, I cannot see anywhere that ofyFactory is ever instantiated, so I am not sure how it would ever not be null. What am I missing?

Here's a stacktrace:

java.lang.NullPointerException
    at com.gwtplatform.crawlerservice.server.service.ObjectifyDao.ofy(ObjectifyDao.java:121)
    at com.gwtplatform.crawlerservice.server.service.ObjectifyDao.listKeysByProperty(ObjectifyDao.java:102)
    at com.gwtplatform.crawlerservice.server.CrawlServiceServlet.doGet(CrawlServiceServlet.java:90)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    at com.google.inject.servlet.ServletDefinition.doService(ServletDefinition.java:263)
    at com.google.inject.servlet.ServletDefinition.service(ServletDefinition.java:178)
    at com.google.inject.servlet.ManagedServletPipeline.service(ManagedServletPipeline.java:91)
    at com.google.inject.servlet.FilterChainInvocation.doFilter(FilterChainInvocation.java:62)
    at com.pixelelephant.server.filters.EncodingFilter.doFilter(EncodingFilter.java:22)
    at com.google.inject.servlet.FilterDefinition.doFilter(FilterDefinition.java:163)
    at com.google.inject.servlet.FilterChainInvocation.doFilter(FilterChainInvocation.java:58)
    at com.googlecode.objectify.cache.AsyncCacheFilter.doFilter(AsyncCacheFilter.java:59)
    at com.googlecode.objectify.ObjectifyFilter.doFilter(ObjectifyFilter.java:49)
    at com.google.inject.servlet.FilterDefinition.doFilter(FilterDefinition.java:163)
    at com.google.inject.servlet.FilterChainInvocation.doFilter(FilterChainInvocation.java:58)
    at com.google.inject.servlet.ManagedFilterPipeline.dispatch(ManagedFilterPipeline.java:118)
    at com.google.inject.servlet.GuiceFilter.doFilter(GuiceFilter.java:113)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.appstats.AppstatsFilter.doFilter(AppstatsFilter.java:141)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.api.socket.dev.DevSocketFilter.doFilter(DevSocketFilter.java:74)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.ResponseRewriterFilter.doFilter(ResponseRewriterFilter.java:123)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:34)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:63)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:125)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.DevAppServerServersFilter.doDirectRequest(DevAppServerServersFilter.java:369)
    at com.google.appengine.tools.development.DevAppServerServersFilter.doDirectServerRequest(DevAppServerServersFilter.java:352)
    at com.google.appengine.tools.development.DevAppServerServersFilter.doFilter(DevAppServerServersFilter.java:115)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
    at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
    at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
    at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
    at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
    at com.google.appengine.tools.development.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:97)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:480)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at org.mortbay.jetty.Server.handle(Server.java:326)
    at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
    at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923)
    at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:547)
    at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212)
    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
    at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
    at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)

Answer 1

This is definitely a bug in the crawler service and I submitted a patch on github ( https://github.com/ArcBees/GWTP/pull/299 ).

Stay tuned for the next version :)