Hi, You need to add commons.logging to your project. I saw this error when I tried to use rupdate from jena-arq, which also can be an exampe how to write SPARQL update.
Hope it helps, On Wed, Sep 19, 2012 at 3:17 PM, David Moss <[email protected]> wrote: > I've been banging my head against the wall until the early hours trying to > make Jena post an insert to a sparql endpoint. > I notice there is no code on the net to use as a guide on this topic. > > Initially I thought my server wasn't responding to update requests, but I > installed fuseki and set it it accept updates from the command line. Still > no joy. I could send updates with fuseki's web form, but not from Java > using Jena. > > The code I tried to use from Jena was: > > String update = "http://localhost:3030/ds/update";; > String query = "INSERT {<a> <b> <c>} WHERE {?s ?p ?o}"; > UpdateRequest u = UpdateFactory.create(); > u.add(query); > UpdateProcessRemote p = new UpdateProcessRemote(u, update); > p.execute(); > > No matter what I tried the code would fail deep in the processing of > p.execute() > > I even tried writing my own html page with a form to send the query, just > to prove it would be accepted and processed by fuseki. > It was. > > The error dump from the above code is as follows: > > ****************** > 0 [AWT-EventQueue-0] INFO jenatest.jenathing - creating jenathing > Jenathing created > 3382 [AWT-EventQueue-0] DEBUG com.hp.hpl.jena.sparql.mgt. > ARQMgt - Register MBean: com.hp.hpl.jena.sparql.system:type=Context > 3382 [AWT-EventQueue-0] DEBUG com.hp.hpl.jena.sparql.mgt.ARQMgt - Register > MBean: com.hp.hpl.jena.sparql.system:type=Engine > 3499 [AWT-EventQueue-0] DEBUG com.hp.hpl.jena.sparql.mgt.ARQMgt - Register > MBean: com.hp.hpl.jena.sparql.system:type=SystemInfo > 3501 [AWT-EventQueue-0] DEBUG com.hp.hpl.jena.sparql.mgt.ARQMgt - Register > MBean: com.hp.hpl.jena.sparql.system:type=SystemInfo > 3502 [AWT-EventQueue-0] DEBUG com.hp.hpl.jena.sparql.mgt.ARQMgt - Register > MBean: org.openjena.riot.system:type=SystemInfo > 4018 [AWT-EventQueue-0] DEBUG org.openjena.riot.web.HttpOp - [1] POST > http://localhost:3030/ds/update > Exception in thread "AWT-EventQueue-0" java.lang.NoClassDefFoundError: > org/apache/commons/logging/LogFactory > at > org.apache.http.impl.client.AbstractHttpClient.<init>(AbstractHttpClient.java:182) > at > org.apache.http.impl.client.DefaultHttpClient.<init>(DefaultHttpClient.java:150) > at org.openjena.riot.web.HttpOp.execHttpPost(HttpOp.java:206) > at org.openjena.riot.web.HttpOp.execHttpPost(HttpOp.java:154) > at org.openjena.riot.web.HttpOp.execHttpPost(HttpOp.java:128) > at > com.hp.hpl.jena.sparql.modify.UpdateProcessRemote.execute(UpdateProcessRemote.java:60) > at jenatest.jenathing.doUpdate(jenathing.java:65) > ************************* > and this seems to be the culprit: > <init>(AbstractHttpClient.java:182) > > when it gets to line 206 in HttpOp.java > > // Execute > HttpClient httpclient = new DefaultHttpClient(); > > it hangs for a bit and then never actually executes the subsequent lines: > > httppost.setEntity(provider) ; > HttpResponse response = httpclient.execute(httppost) ; > httpResponse(id, response, baseIRI, handlers) ; > > httpclient.getConnectionManager().shutdown(); > > it skips over these and > } catch (IOException ex) > { > ex.printStackTrace(System.err) ; > } > > straight to the finally clause: > > finally { closeEntity(provider) ; } > } > > So it doesn't work and the problem seems to be deeply hidden within the > Apache stuff. > > Eventually after staying up till past 3am and missing a days work today, I > sidestepped the issue entirely and wrote (or rather cut-and-pasted) an > update routine that ignored the Jena stuff altogether. Not my preferred > option, but enough is enough. > > I replaced the code above with: > > String update = "http://localhost:3030/ds/update";; > String query = "INSERT {<a> <b> <c>} WHERE {?s ?p ?o}"; > postthing p = new postthing(); > p.setEndpoint(update); > p.setUpdateString(query); > try { > p.execute(); > } > catch (Exception e) { > logger.error(e.toString()); > } > > where the postthing is defined as: > > > ****************************** > package jenatest; > > import java.io.BufferedReader; > import java.io.InputStreamReader; > import java.io.OutputStreamWriter; > import java.net.URL; > import java.net.URLConnection; > import java.net.URLEncoder; > > /** > * > * @author admos0 > */ > public class postthing { > > private String updateString = ""; > private String endpoint = ""; > > postthing() { > // empty constructor > } > > postthing(String input) { > this.updateString = input; > } > > /** > * @param set the endpoint > */ > public void setEndpoint(String endpoint) { > this.endpoint = endpoint; > } > > /** > * @return the endpoint > */ > public String getEndpoint() { > return this.endpoint; > } > > > /** > * @method execute the update > */ > void execute() throws Exception { > try { > > if (this.endpoint.equals("")) throw new Exception("No endpoint > specified"); > if (this.updateString.equals("")) throw new Exception("no > update string specified"); > > > // Construct data > String data = URLEncoder.encode("request", "UTF-8") + "=" + > URLEncoder.encode(this.getUpdateString(), "UTF-8"); > > > // Send data > URL url = new URL(endpoint); > > URLConnection conn = url.openConnection(); > conn.setDoOutput(true); > OutputStreamWriter wr = new > OutputStreamWriter(conn.getOutputStream()); > wr.write(data); > wr.flush(); > > // Get the response > BufferedReader rd = new BufferedReader(new > InputStreamReader(conn.getInputStream())); > String line; > while ((line = rd.readLine()) != null) { > // Process line... > } > wr.close(); > rd.close(); > } catch (Exception e) { throw e; > } > > } > > /** > * @return the updateString > */ > public String getUpdateString() { > return updateString; > } > > /** > * @param updateString the updateString to set > */ > public void setUpdateString(String updateString) { > this.updateString = updateString; > } > } > *********************** > > Now it works. I can insert triples into my sparql update endpoint. > > There has to be a deep bug in the Apache routines that come with Jena that > thwarted my previous efforts and I hope someone notices this and fixes it. > > In the meantime I'm happy that I have something that works, and I hope that > by posting here the recipe for updating a remote sparql endpoint will > become available and more people will take up Jena and Fuseki. > > David Moss
