Hi, For an in house R&D project, I've recently been working with adding some functionality to the Fuseki UI.
First I start the server law@lawx:~/Downloads/Lewis/code/essem-fuseki/target/essem-fuseki-0.2.8-SNAPSHOT$ ./fuseki-server --update --mem /susman 14:15:45 INFO Server :: Dataset: in-memory 14:15:45 INFO Config :: Home Directory: /home/law/Downloads/Lewis/code/essem-fuseki/target/essem-fuseki-0.2.8-SNAPSHOT 14:15:45 INFO Server :: Dataset path = /susman 14:15:45 INFO Server :: Fuseki 0.2.8-SNAPSHOT 2013-08-01T14:15:02-0700 14:15:45 INFO Server :: Started 2013/08/01 14:15:45 PDT on port 3030 Then I manually upload some triples from four different OWL files 14:16:27 INFO Fuseki :: [1] POST http://localhost:3030/susman/upload 14:16:27 INFO Fuseki :: [1] Upload: Filename: AssemblyProcess.owl, Content-Type=text/xml, Charset=null => RDF/XML 14:16:27 INFO Fuseki :: [1] Upload: Filename: AutomobileManufacturing.owl, Content-Type=text/xml, Charset=null => RDF/XML 14:16:27 INFO Fuseki :: [1] Upload: Filename: JoiningProcess.owl, Content-Type=text/xml, Charset=null => RDF/XML 14:16:27 INFO Fuseki :: [1] Upload: Filename: MaterialHandlingEquipment.owl, Content-Type=text/xml, Charset=null => RDF/XML 14:16:27 INFO Fuseki :: [1] Upload: Graph: default (1148 triple(s)) 14:16:27 INFO Fuseki :: [1] 200 OK (306 ms) But I am experiencing a real nasty issue when I attempt to execute a query via the "Get Results" button. My query is as follows PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> PREFIX mheq: < http://eil.stanford.edu:443/svn/eil-repo/Users/Lewis/ontology/MaterialHandlingEquipment.owl# > DESCRIBE ?individual WHERE { ?individual rdf:type mheq:BeltConveyor. } I get the following 14:16:44 INFO Fuseki :: [2] GET http://localhost:3030/sparql?query=PREFIX+rdf%3A+%3Chttp%3A%2F%2Fwww.w3.org%2F1999%2F02%2F22-rdf-syntax-ns%23%3E%0D%0APREFIX+mheq%3A+%3Chttp%3A%2F%2Feil.stanford.edu%3A443%2Fsvn%2Feil-repo%2FUsers%2FLewis%2Fontology%2FMaterialHandlingEquipment.owl%23%3E%0D%0ADESCRIBE+%3Findividual%0D%0AWHERE+%7B%0D%0A+%3Findividual+rdf%3Atype+mheq%3ABeltConveyor.++%0D%0A%7D++&default-graph-uri=&output=json&stylesheet=%2Fxml-to-html.xsl 14:16:44 WARN Fuseki :: [2] RC = 500 : null java.lang.NullPointerException at org.apache.jena.fuseki.servlets.SPARQL_ServletBase.mapRequestToService(SPARQL_ServletBase.java:311) at org.apache.jena.fuseki.servlets.SPARQL_ServletBase.execCommonWorker(SPARQL_ServletBase.java:153) at org.apache.jena.fuseki.servlets.SPARQL_ServletBase.doCommon(SPARQL_ServletBase.java:78) at org.apache.jena.fuseki.servlets.SPARQL_Query.doGet(SPARQL_Query.java:64) at javax.servlet.http.HttpServlet.service(HttpServlet.java:735) at javax.servlet.http.HttpServlet.service(HttpServlet.java:848) at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:684) at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1448) at org.eclipse.jetty.servlets.UserAgentFilter.doFilter(UserAgentFilter.java:82) at org.eclipse.jetty.servlets.GzipFilter.doFilter(GzipFilter.java:294) at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1419) at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:455) at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:229) at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1075) at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:384) at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:193) at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1009) at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:135) at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:116) at org.eclipse.jetty.server.Server.handle(Server.java:370) at org.eclipse.jetty.server.AbstractHttpConnection.handleRequest(AbstractHttpConnection.java:489) at org.eclipse.jetty.server.BlockingHttpConnection.handleRequest(BlockingHttpConnection.java:53) at org.eclipse.jetty.server.AbstractHttpConnection.headerComplete(AbstractHttpConnection.java:949) at org.eclipse.jetty.server.AbstractHttpConnection$RequestHandler.headerComplete(AbstractHttpConnection.java:1011) at org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:644) at org.eclipse.jetty.http.HttpParser.parseAvailable(HttpParser.java:235) at org.eclipse.jetty.server.BlockingHttpConnection.handle(BlockingHttpConnection.java:72) at org.eclipse.jetty.server.nio.BlockingChannelConnector$BlockingChannelEndPoint.run(BlockingChannelConnector.java:298) at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:608) at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:543) at java.lang.Thread.run(Thread.java:724) 14:16:44 INFO Fuseki :: [2] 500 Server Error (3 ms) So line 311 of SPARQL_ServletBase.mapRequestToService(DatasetRef dsRef, String uri, String serviceName) looks like this... if ( dsRef.name.length() >= uri.length() ) A confession here is that I've come to the list before I begin debugging this in Eclipse... which is where I am working on the code. Has anyone had problems with "Getting Results" within the Fuseki WebApp before e.g. has anyone seen a NPE around SPARQL_ServletBase before? A quick look through the archives did not bring anything up for me so I'm sending it here in parallel with DEBUG'ing the code myself. Thanks in advance Best Lewis -- *Lewis*
