JENA-1366: Fuseki embedded as a standalone server

[afs]

No description provided.

[kinow]

Planning to test it this weekend, but in case I take too long, the pull request is only adding code, that seems good to me. I want to give it a try so that I learn what it is doing, and can also perhaps help with the documentation later :-)

[kinow]

Pretty much everything worked. Here's what I did.

$ git fetch -p --all ; git checkout pr/265
$ mvn clean install -Pdev -skipTests
$ cd jena-fuseki2/jena-fuseki-basic
$ ./run-sparqler

Then went to http://localhost:3030, and all good. Quickly clicked on the menu items, trying to validate/parse the default queries...

Looked at the console and got the following when using the RDF data validator.

23:07:11 WARN  Request              :: Exception in validationRequest
org.apache.jena.riot.RiotException: No source specified
	at org.apache.jena.riot.RDFParserBuilder.build(RDFParserBuilder.java:459)
	at org.apache.jena.fuseki.validation.html.DataValidatorHTML.executeHTML(DataValidatorHTML.java:97)
	at org.apache.jena.fuseki.validation.DataValidator.executeHTML(DataValidator.java:36)
	at org.apache.jena.fuseki.validation.ValidatorBase.execute(ValidatorBase.java:119)
	at org.apache.jena.fuseki.validation.ValidatorBase.doPost(ValidatorBase.java:60)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
	at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:841)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1650)
	at org.apache.jena.fuseki.servlets.FusekiFilter.doFilter(FusekiFilter.java:99)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1637)
	at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:533)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:188)
	at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1253)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:168)
	at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:473)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:166)
	at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1155)
	at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
	at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
	at org.eclipse.jetty.server.Server.handle(Server.java:564)
	at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:317)
	at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:251)
	at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:279)
	at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:110)
	at org.eclipse.jetty.io.ChannelEndPoint$2.run(ChannelEndPoint.java:124)
	at org.eclipse.jetty.util.thread.Invocable.invokePreferred(Invocable.java:128)
	at org.eclipse.jetty.util.thread.Invocable$InvocableExecutor.invoke(Invocable.java:222)
	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:294)
	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:199)
	at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:672)
	at org.eclipse.jetty.util.thread.QueuedThreadPool$2.run(QueuedThreadPool.java:590)
	at java.lang.Thread.run(Thread.java:748)

Then I thought there could be something wrong with the default Turtle. Tried with the first example from https://www.w3.org/TR/turtle/, and left the checkbox selected to Turtle. Still same problem.

@base <http://example.org/> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix foaf: <http://xmlns.com/foaf/0.1/> .
@prefix rel: <http://www.perceive.net/schemas/relationship/> .

<#green-goblin>
    rel:enemyOf <#spiderman> ;
    a foaf:Person ;    # in the context of the Marvel universe
    foaf:name "Green Goblin" .

<#spiderman>
    rel:enemyOf <#green-goblin> ;
    a foaf:Person ;
    foaf:name "Spiderman", "Человек-паук"@ru .

The problem seems to happen here

jena/jena-arq/src/main/java/org/apache/jena/riot/RDFParserBuilder.java

Line 458 in 2e361da

if ( uri == null && path == null && content == null && inputStream == null && javaReader == null )

However, I'm not sure with that's expected behaviour or bug... I have the impression we want to validate it, but without having a file/stream/reader. Just the content?

Does that make sense?

Hope that helps
Bruno

[kinow]

Double checked the messages displayed to user, all look goods, no typos or confusing text. Very simple to understand how to use it. The provided shell scripts are helpful too, as well as comments in Java and shell in case users want to customize it.

shellcheck complains only about some strings not quoted in the run-sparqler script.

kinow@localhost:~/Development/java/jena/jena/jena-fuseki2/jena-fuseki-basic/sparqler$ shellcheck run-sparqler 

In run-sparqler line 55:
    exec java $JVM_ARGS $FUSEKI_LOG -jar $FUSEKI_JAR $SPARQLER_ARGS
              ^-- SC2086: Double quote to prevent globbing and word splitting.
                        ^-- SC2086: Double quote to prevent globbing and word splitting.
                                         ^-- SC2086: Double quote to prevent globbing and word splitting.
                                                     ^-- SC2086: Double quote to prevent globbing and word splitting.


In run-sparqler line 59:
    nohup java $JVM_ARGS $FUSEKI_LOG -jar $FUSEKI_JAR $SPARQLER_ARGS > nohup.log 2>&1 &
               ^-- SC2086: Double quote to prevent globbing and word splitting.
                         ^-- SC2086: Double quote to prevent globbing and word splitting.
                                          ^-- SC2086: Double quote to prevent globbing and word splitting.
                                                      ^-- SC2086: Double quote to prevent globbing and word splitting.

[afs]

shellcheck needs to try harder :-)

I'll fix $FUSEKI_JAR. The others are supposed to expand to zero, one or more exec arguments.

[afs]

Error No source specified fixed.

[kinow]

Everything working now 👍

[afs]

Thanks!

The module structure of Fuseki2 is now a bit messy, but tolerable. What the right structure is can wait; it needs to balance usefulness (not too many module) with detailed structure (each different aspect a module).