ng4j-namedgraphs — Discussion of Named Graphs in RDF

[namedgraphs] Using NG4J With SDB

[Chris S. <chr...@is...>]

Hello,
    I am really interested in using NG4J in a project I am working on.  However, the only thing holding me back is that I'd like to back the NG4J usage with the Jena SDB datastore.  I noticed that NG4J has its own Database storage implementation but I was wondering if anyone has been able to successfully plugin SDB in use with NG4J?  Since they both work with the Jena configuration and support named graphs it seems that there should be a way to work with both - I'm having trouble getting it to work however.  If anyone could help, I'd greatly appreciate it.

Thanks,
Chris

Re: [namedgraphs] Maven Coordinates?

[Jennifer C. <jen...@at...>]

I meant to also mention that Tim has been kind enough to host the maven
repository for us.  Looks like I have a chance to say that now since I
neglected to cc the mailing list in the earlier message.  
 
Jennifer

  _____  

From: Jennifer Cormier [mailto:jen...@at...] 
Sent: Tuesday, February 02, 2010 10:28 AM
To: 'Chris Shellenbarger'
Subject: RE: [namedgraphs] Maven Coordinates?


Chris,
 
Sorry for the inconvenience.  I did not realize that the maven information
is not posted somewhere easy to find.  We'll have to add more details to
the project wiki.
 
This old mailing list post
(http://sourceforge.net/mailarchive/message.php?msg_name=200908261646.0428
8.tim.pizey%40oucs.ox.ac.uk) by Tim says "I have just deployed to maven
repository at http://melati.org/maven2/ and deployed the maven generated
project web site at http://paneris.net/ng4j/index.html".
 
I don't yet use Maven myself, so if you (or anyone who does) would like to
add some information on that to the wiki just request an account as
described here
(http://sourceforge.net/apps/mediawiki/ng4j/index.php?title=NG4J_Wiki#Wiki
_Information).  Or send me some basic information and I can format and
post it.
 
Let us know if there are any problems accessing the maven repository.  And
thanks for using NG4J!
 
Jennifer
 


  _____  

From: Chris Shellenbarger [mailto:chr...@is...] 
Sent: Tuesday, February 02, 2010 8:59 AM
To: ng4...@li...
Subject: [namedgraphs] Maven Coordinates?



Hello,

    Could anyone please assist me in locating the maven
coordinates/repository information which will allow me to download NG4J
from a maven repository?   Any help would be greatly appreciated.

 

Thanks,

Chris

[namedgraphs] Maven Coordinates?

[Chris S. <chr...@is...>]

Hello,
    Could anyone please assist me in locating the maven coordinates/repository information which will allow me to download NG4J from a maven repository?   Any help would be greatly appreciated.

Thanks,
Chris

Re: [namedgraphs] Twitter: @olafhartig Arrived in Siem Reap, Cambodia, finally!

[<ha...@in...>]

Hey,

> Hi Jennifer,
>
> I think we can probably take it that Olaf won't be answering mail for a
> bit.

Yes, i'm on vacation at the moment. I'll be back in the middle of Feb.

Greetings,
Olaf

[namedgraphs] Twitter: @olafhartig Arrived in Siem Reap, Cambodia, finally!

[Tim P. <ti...@pa...>]

Hi Jennifer,

I think we can probably take it that Olaf won't be answering mail for a bit.

cheers
Tim

Re: [namedgraphs] [Fwd: Re: Problem related to Jena 2.6.0]

[Tim P. <ti...@pa...>]

Hi Jennifer, 

On Thursday 21 January 2010 00:21:53 Jennifer Cormier wrote:
> Hi Tim,
> 
> Thanks very much for your work on this!
> 
> > Shall I commit these changes?
> 
> That's a good question.  If the changes are backwards-compatible (i.e.
> don't require anything from Jena 2.6.2 or its dependencies) then it
> shouldn't be a problem.  If they're not then we need to decide.
> 
> In what package (and jar) does the LiteralLabelFactory class live?
> 
> 
> Jennifer

All I did was change the version of the jar (jenatest is no longer a dependency, 
if I remember correctly we knew this was the plan at the next version)

All the tests pass. 

As far as I can see this is a minor refactoring in Jena which we are just copying.

Indeed the code even has a comment to the effect that the original was 
copied without comprehension.

So I would say that the thing to do is to commit these minor changes, 
update the jar files in lib and issue another version. 

This is getting increasingly easy. 

The important thing, in my view, is to remain in lock step with Jena. 
I may not notice when new versions of Jena are released and am happy 
to be nudged when this happens. 

cheers
Tim




-- 
We are in dialogue.

Re: [namedgraphs] [Fwd: Re: Problem related to Jena 2.6.0]

[Jennifer C. <jen...@at...>]

Hi Tim,

Thanks very much for your work on this!

> Shall I commit these changes?

That's a good question.  If the changes are backwards-compatible (i.e.
don't require anything from Jena 2.6.2 or its dependencies) then it
shouldn't be a problem.  If they're not then we need to decide.

In what package (and jar) does the LiteralLabelFactory class live?


Jennifer



-----Original Message-----
From: Tim Pizey [mailto:ti...@pa...]
Sent: Wednesday, January 20, 2010 7:44 AM
To: Riccardo Tasso; ng4...@li...
Subject: Re: [namedgraphs] [Fwd: Re: Problem related to Jena 2.6.0]

Hi Riccardo,

 I have done a fresh checkout.
 I use Maven to build ng4j.

 Editted pom.xml to use 2.6.0 for jena and jenatest..

 then executed:

 mvn install

 However the connection to the jena repository timed out.
 As you probably know there have been some upheavals in the jena
ecosystem.

 I changed the repository location to http://openjena.org/repo/
 (not strictly necessary as these are mirrored)

 This resulted in:

 INFO] Compilation failure


/home/timp/workspace/ng4j/src/de/fuberlin/wiwiss/ng4j/trix/TriXReader.java
:[162,35]
 com.hp.hpl.jena.graph.impl.LiteralLabel is abstract; cannot be
 instantiated


/home/timp/workspace/ng4j/src/de/fuberlin/wiwiss/ng4j/trix/TriXReader.java
:[172,35]
 com.hp.hpl.jena.graph.impl.LiteralLabel is abstract; cannot be
 instantiated


/home/timp/workspace/ng4j/src/de/fuberlin/wiwiss/ng4j/trix/TriXReaderWithE
xtensions.java:[168,35]
 com.hp.hpl.jena.graph.impl.LiteralLabel is abstract; cannot be
 instantiated


/home/timp/workspace/ng4j/src/de/fuberlin/wiwiss/ng4j/trix/TriXReaderWithE
xtensions.java:[178,35]
 com.hp.hpl.jena.graph.impl.LiteralLabel is abstract; cannot be
 instantiated


 which is the same problem as you.

 I then did
  mvn -DdownloadJavadocs=true -DdownloadSources=true eclipse:clean
 eclipse:eclipse
 which creates a new set of eclipse configuration files.

 In TriXReader substitute:

        public void objectPlainLiteral(String value, String lang) {
                LiteralLabel ll = LiteralLabelFactory.create(value, lang);
        this.object =  Node.createLiteral(ll);
                addTriple();
        }

        public void objectTypedLiteral(String value, String datatypeURI) {
                // No idea what that line does, is copy&paste from
ModelCom.createTypedLiteral
                RDFDatatype dt =
TypeMapper.getInstance().getSafeTypeByName(datatypeURI);
                LiteralLabel ll =
LiteralLabelFactory.createLiteralLabel( value, "", dt );
        this.object =  Node.createLiteral(ll);
                addTriple();
        }


 In TriXReaderWithExtensions we do the same (cut and paste issues :( )

        public void objectPlainLiteral(String value, String lang) {
                LiteralLabel ll = LiteralLabelFactory.create(value, lang);
        this.object =  Node.createLiteral(ll);
                addTriple();
        }

        public void objectTypedLiteral(String value, String datatypeURI) {
                // No idea what that line does, is copy&paste from
ModelCom.createTypedLiteral
                RDFDatatype dt =
TypeMapper.getInstance().getSafeTypeByName(datatypeURI);
                LiteralLabel ll =
LiteralLabelFactory.createLiteralLabel( value, "", dt );
        this.object =  Node.createLiteral(ll);
                addTriple();
        }

 This gets us working with Eclipse and Maven.

 Shall I commit these changes?

 cheers
 Tim


2010/1/18 Riccardo Tasso wrote:
> Hi Tim,
>   I've just imported NG4J 0.9.2 sourcecode as an Eclipse project and
changed
> every library referring to jena 2.6.0 in the corresponding jena 2.6.2.
> I have 4 errors (of the same type fortunately). Two of them in the class
> de.fuberlin.wiwiss.ng4j.trix.TriXReader (lines 162 and 172) and two in
the
> class de.fuberlin.wiwiss.ng4j.trix.TriXReaderWithExtensions (lines 168
and
> 178).
>
> The error is in the instructions:
>   new LiteralLabel(value, lang);
>   new LiteralLabel(value, null, dt);
> and the report is:
> "Cannot instantiate the type LiteralLabel"
>
> Can you help me in solving this issue?
> Thank you,
>   Riccardo
>

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Re: [namedgraphs] [Fwd: Re: Problem related to Jena 2.6.0]

[Tim P. <ti...@pa...>]

Hi Riccardo,

 I have done a fresh checkout.
 I use Maven to build ng4j.

 Editted pom.xml to use 2.6.0 for jena and jenatest..

 then executed:

 mvn install

 However the connection to the jena repository timed out.
 As you probably know there have been some upheavals in the jena ecosystem.

 I changed the repository location to http://openjena.org/repo/
 (not strictly necessary as these are mirrored)

 This resulted in:

 INFO] Compilation failure

 /home/timp/workspace/ng4j/src/de/fuberlin/wiwiss/ng4j/trix/TriXReader.java:[162,35]
 com.hp.hpl.jena.graph.impl.LiteralLabel is abstract; cannot be
 instantiated

 /home/timp/workspace/ng4j/src/de/fuberlin/wiwiss/ng4j/trix/TriXReader.java:[172,35]
 com.hp.hpl.jena.graph.impl.LiteralLabel is abstract; cannot be
 instantiated

 /home/timp/workspace/ng4j/src/de/fuberlin/wiwiss/ng4j/trix/TriXReaderWithExtensions.java:[168,35]
 com.hp.hpl.jena.graph.impl.LiteralLabel is abstract; cannot be
 instantiated

 /home/timp/workspace/ng4j/src/de/fuberlin/wiwiss/ng4j/trix/TriXReaderWithExtensions.java:[178,35]
 com.hp.hpl.jena.graph.impl.LiteralLabel is abstract; cannot be
 instantiated


 which is the same problem as you.

 I then did
  mvn -DdownloadJavadocs=true -DdownloadSources=true eclipse:clean
 eclipse:eclipse
 which creates a new set of eclipse configuration files.

 In TriXReader substitute:

        public void objectPlainLiteral(String value, String lang) {
                LiteralLabel ll = LiteralLabelFactory.create(value, lang);
        this.object =  Node.createLiteral(ll);
                addTriple();
        }

        public void objectTypedLiteral(String value, String datatypeURI) {
                // No idea what that line does, is copy&paste from
ModelCom.createTypedLiteral
                RDFDatatype dt =
TypeMapper.getInstance().getSafeTypeByName(datatypeURI);
                LiteralLabel ll =
LiteralLabelFactory.createLiteralLabel( value, "", dt );
        this.object =  Node.createLiteral(ll);
                addTriple();
        }


 In TriXReaderWithExtensions we do the same (cut and paste issues :( )

        public void objectPlainLiteral(String value, String lang) {
                LiteralLabel ll = LiteralLabelFactory.create(value, lang);
        this.object =  Node.createLiteral(ll);
                addTriple();
        }

        public void objectTypedLiteral(String value, String datatypeURI) {
                // No idea what that line does, is copy&paste from
ModelCom.createTypedLiteral
                RDFDatatype dt =
TypeMapper.getInstance().getSafeTypeByName(datatypeURI);
                LiteralLabel ll =
LiteralLabelFactory.createLiteralLabel( value, "", dt );
        this.object =  Node.createLiteral(ll);
                addTriple();
        }

 This gets us working with Eclipse and Maven.

 Shall I commit these changes?

 cheers
 Tim


2010/1/18 Riccardo Tasso wrote:
> Hi Tim,
>   I've just imported NG4J 0.9.2 sourcecode as an Eclipse project and changed
> every library referring to jena 2.6.0 in the corresponding jena 2.6.2.
> I have 4 errors (of the same type fortunately). Two of them in the class
> de.fuberlin.wiwiss.ng4j.trix.TriXReader (lines 162 and 172) and two in the
> class de.fuberlin.wiwiss.ng4j.trix.TriXReaderWithExtensions (lines 168 and
> 178).
>
> The error is in the instructions:
>   new LiteralLabel(value, lang);
>   new LiteralLabel(value, null, dt);
> and the report is:
> "Cannot instantiate the type LiteralLabel"
>
> Can you help me in solving this issue?
> Thank you,
>   Riccardo
>

[namedgraphs] Test subscriptiopn email address change, please ignore

[Tim P. <ti...@pa...>]

Hi,
posted from google.
Tim

Re: [namedgraphs] [Fwd: Re: Problem related to Jena 2.6.0]

[Riccardo T. <ta...@el...>]

Hi Tim,
    I've just imported NG4J 0.9.2 sourcecode as an Eclipse project and 
changed every library referring to jena 2.6.0 in the corresponding jena 
2.6.2.
I have 4 errors (of the same type fortunately). Two of them in the class 
de.fuberlin.wiwiss.ng4j.trix.TriXReader (lines 162 and 172) and two in 
the class de.fuberlin.wiwiss.ng4j.trix.TriXReaderWithExtensions (lines 
168 and 178).

The error is in the instructions:
    new LiteralLabel(value, lang);
    new LiteralLabel(value, null, dt);
and the report is:
"Cannot instantiate the type LiteralLabel"

Can you help me in solving this issue?
Thank you,
    Riccardo

Tim Pizey ha scritto:
> Hi Riccardo,
>
> It should be a relatively straight-forward thing to update to the latest jena.
>
> I would ask what is the functionality in ng4j that you want to use?
>
> ng4j has an assortment of features, only one of which is named graphs.
>
> My understanding is that the named graphs features have been
> re-implemented within jena itself.
>
> yours
> Tim Pizey
>
> 2010/1/12 Riccardo Tasso <ta...@el...>:
>   
>> -------- Messaggio Originale --------
>> Oggetto:        Re: [namedgraphs] Problem related to Jena 2.6.0
>> Data:   Tue, 12 Jan 2010 16:35:09 +0100
>> Da:     Riccardo Tasso <ta...@el...>
>> A:      Jennifer Cormier <jen...@at...>
>> CC:     ng4...@li..., 'Tim Pizey'
>> <tim...@ou...>
>> Referenze:      <4B4...@el...>
>> <00e901ca92ee$93f48db0$7801a8c0@ATC73>
>>
>>
>>
>> Thank you Jennifer,
>>  I'm really interested in the possibilities which named graphs could offer
>> to my project. In the next days I'll try to import in Eclipse the NG4J
>> source and to update Jena libraries to see if it's immediate. Then I'll make
>> you know my results.
>>
>> Riccardo
>>
>> Jennifer Cormier ha scritto:
>>     
>>> Hi Riccardo,
>>>
>>> It's great to hear you are using to NG4J!  Sorry that its version of Jena
>>> seems to be causing problems.
>>>
>>> Last summer Tim Pizey had NG4J working locally against a
>>> pre-Jena-2.6.2-snapshot.  I don't know whether anyone has worked on that
>>> since.
>>>
>>> Tim?  Anyone?
>>>
>>>
>>> Jennifer
>>>
>>> -----Original Message-----
>>> From: Riccardo Tasso [mailto:ta...@el...] Sent: Monday, January
>>> 11, 2010 8:47 AM
>>> To: ng4...@li...
>>> Subject: [namedgraphs] Problem related to Jena 2.6.0
>>>
>>> Hi everybody,
>>>    I'm starting a project using NG4J and I'm currently using the lastest
>>> version (0.9.2) which is based on Jena 2.6.0. In these days I tried to
>>> validate a RDF dataset with a RDF Schema but it gives me problems with Jena
>>> 2.6.0 but it works ok with Jena 2.6.2. Is it possible to update the NG4J
>>> making it use Jena 2.6.0?
>>>
>>> If you like I could get more specific about my problem, but I'm pretty
>>> sure it regards more Jena than NG4J.
>>>
>>> Thanks,
>>>    Riccardo
>>>
>>> --------------------------------------------------------------------------
>>> ----
>>> This SF.Net email is sponsored by the Verizon Developer Community
>>> Take advantage of Verizon's best-in-class app development support
>>> A streamlined, 14 day to market process makes app distribution fast and
>>> easy
>>> Join now and get one step closer to millions of Verizon customers
>>> http://p.sf.net/sfu/verizon-dev2dev
>>> _______________________________________________
>>> ng4j-namedgraphs mailing list
>>> ng4...@li...
>>> https://lists.sourceforge.net/lists/listinfo/ng4j-namedgraphs
>>>
>>>       
>>
>>     

Re: [namedgraphs] [Fwd: Re: Problem related to Jena 2.6.0]

[Riccardo T. <ta...@el...>]

I'm using NG4J for this task:

* I have n RDF sources containing statements about many entities (e.g. 
name, email, SN);
* each source has a provenance, a date and a trust value, that's why I 
represent each one of them with a Named Graph;
* some sources may contain the same entities but with different URIs 
(e.g. John Smith in data source 1 is ds1:person1 but in data source 2 is 
ds2:person 47);
* I create a default graph containing only assertion such as:
        <default:person2, owl:sameAs, ds1:person1>
        <default:person2, owl:sameAs, ds1:person1>
* this match is performed by the key value of each entity (e.g. SN);
* if two data sources say something contraddictory (e.g. the same person 
has different salaries) I would like to perform queries such has:
       which is the salary of this person by the source with the highest 
trust value;
       which is the salary of this person by the most recent source;
       how many datasources state that this person has this salary;

Hence I need a model containing all the data from each datasource plus 
the default graph with a reasoner capable to infer owl:sameAs 
relationship without loosing the provenance of each triple.
Do you think NG4J is good for this task? I thought to try it because I 
didn't know about Jena TDB. Could anyone go into more depth about the 
different approaches?

Thanks,
    Riccardo

Jennifer Cormier ha scritto:
> I remember looking into the "named graphs" feature of the Jena TDB release
> last year.  Based on what I recall, it was quite different from NG4J's
> implementation.  Individual graphs are stored separately and must be
> loaded individually.
>
> In the NG4J implementation, a quad store is used so that each triple is
> associated with a 4th item, that being the graph name.  It is possible to
> search using SPARQL over an entire dataset, across graphs, and get only
> those quads of interest, whether or not they are in the same graph.
>
> It's possible that Jena offers another type of "named graph" support, or
> that I misremember the details.  This is based upon my recollection.
>
>
> Jennifer
>
>
> -----Original Message-----
> From: tim...@go... [mailto:tim...@go...] On Behalf
> Of Tim Pizey
> Sent: Tuesday, January 12, 2010 11:10 AM
> To: Riccardo Tasso; jen...@at...;
> ng4...@li...
> Subject: Re: [Fwd: Re: [namedgraphs] Problem related to Jena 2.6.0]
>
> Hi Riccardo,
>
> It should be a relatively straight-forward thing to update to the latest
> jena.
>
> I would ask what is the functionality in ng4j that you want to use?
>
> ng4j has an assortment of features, only one of which is named graphs.
>
> My understanding is that the named graphs features have been
> re-implemented within jena itself.
>
> yours
> Tim Pizey
>
> 2010/1/12 Riccardo Tasso <ta...@el...>:
>   
>> -------- Messaggio Originale --------
>> Oggetto:        Re: [namedgraphs] Problem related to Jena 2.6.0
>> Data:   Tue, 12 Jan 2010 16:35:09 +0100
>> Da:     Riccardo Tasso <ta...@el...>
>> A:      Jennifer Cormier <jen...@at...>
>> CC:     ng4...@li..., 'Tim Pizey'
>> <tim...@ou...>
>> Referenze:      <4B4...@el...>
>> <00e901ca92ee$93f48db0$7801a8c0@ATC73>
>>
>>
>>
>> Thank you Jennifer,
>>  I'm really interested in the possibilities which named graphs could
>>     
> offer
>   
>> to my project. In the next days I'll try to import in Eclipse the NG4J
>> source and to update Jena libraries to see if it's immediate. Then I'll
>>     
> make
>   
>> you know my results.
>>
>> Riccardo
>>
>> Jennifer Cormier ha scritto:
>>     
>>> Hi Riccardo,
>>>
>>> It's great to hear you are using to NG4J!  Sorry that its version of
>>>       
> Jena
>   
>>> seems to be causing problems.
>>>
>>> Last summer Tim Pizey had NG4J working locally against a
>>> pre-Jena-2.6.2-snapshot.  I don't know whether anyone has worked on
>>>       
> that
>   
>>> since.
>>>
>>> Tim?  Anyone?
>>>
>>>
>>> Jennifer
>>>
>>> -----Original Message-----
>>> From: Riccardo Tasso [mailto:ta...@el...] Sent: Monday,
>>>       
> January
>   
>>> 11, 2010 8:47 AM
>>> To: ng4...@li...
>>> Subject: [namedgraphs] Problem related to Jena 2.6.0
>>>
>>> Hi everybody,
>>>    I'm starting a project using NG4J and I'm currently using the
>>>       
> lastest
>   
>>> version (0.9.2) which is based on Jena 2.6.0. In these days I tried to
>>> validate a RDF dataset with a RDF Schema but it gives me problems with
>>>       
> Jena
>   
>>> 2.6.0 but it works ok with Jena 2.6.2. Is it possible to update the
>>>       
> NG4J
>   
>>> making it use Jena 2.6.0?
>>>
>>> If you like I could get more specific about my problem, but I'm pretty
>>> sure it regards more Jena than NG4J.
>>>
>>> Thanks,
>>>    Riccardo
>>>
>>>
>>>       
> --------------------------------------------------------------------------
>   
>>> ----
>>> This SF.Net email is sponsored by the Verizon Developer Community
>>> Take advantage of Verizon's best-in-class app development support
>>> A streamlined, 14 day to market process makes app distribution fast and
>>> easy
>>> Join now and get one step closer to millions of Verizon customers
>>> http://p.sf.net/sfu/verizon-dev2dev
>>> _______________________________________________
>>> ng4j-namedgraphs mailing list
>>> ng4...@li...
>>> https://lists.sourceforge.net/lists/listinfo/ng4j-namedgraphs
>>>
>>>       
>>
>>     

Re: [namedgraphs] [Fwd: Re: Problem related to Jena 2.6.0]

[Jennifer C. <jen...@at...>]

I remember looking into the "named graphs" feature of the Jena TDB release
last year.  Based on what I recall, it was quite different from NG4J's
implementation.  Individual graphs are stored separately and must be
loaded individually.

In the NG4J implementation, a quad store is used so that each triple is
associated with a 4th item, that being the graph name.  It is possible to
search using SPARQL over an entire dataset, across graphs, and get only
those quads of interest, whether or not they are in the same graph.

It's possible that Jena offers another type of "named graph" support, or
that I misremember the details.  This is based upon my recollection.


Jennifer


-----Original Message-----
From: tim...@go... [mailto:tim...@go...] On Behalf
Of Tim Pizey
Sent: Tuesday, January 12, 2010 11:10 AM
To: Riccardo Tasso; jen...@at...;
ng4...@li...
Subject: Re: [Fwd: Re: [namedgraphs] Problem related to Jena 2.6.0]

Hi Riccardo,

It should be a relatively straight-forward thing to update to the latest
jena.

I would ask what is the functionality in ng4j that you want to use?

ng4j has an assortment of features, only one of which is named graphs.

My understanding is that the named graphs features have been
re-implemented within jena itself.

yours
Tim Pizey

2010/1/12 Riccardo Tasso <ta...@el...>:
>
>
> -------- Messaggio Originale --------
> Oggetto:        Re: [namedgraphs] Problem related to Jena 2.6.0
> Data:   Tue, 12 Jan 2010 16:35:09 +0100
> Da:     Riccardo Tasso <ta...@el...>
> A:      Jennifer Cormier <jen...@at...>
> CC:     ng4...@li..., 'Tim Pizey'
> <tim...@ou...>
> Referenze:      <4B4...@el...>
> <00e901ca92ee$93f48db0$7801a8c0@ATC73>
>
>
>
> Thank you Jennifer,
>  I'm really interested in the possibilities which named graphs could
offer
> to my project. In the next days I'll try to import in Eclipse the NG4J
> source and to update Jena libraries to see if it's immediate. Then I'll
make
> you know my results.
>
> Riccardo
>
> Jennifer Cormier ha scritto:
>>
>> Hi Riccardo,
>>
>> It's great to hear you are using to NG4J!  Sorry that its version of
Jena
>> seems to be causing problems.
>>
>> Last summer Tim Pizey had NG4J working locally against a
>> pre-Jena-2.6.2-snapshot.  I don't know whether anyone has worked on
that
>> since.
>>
>> Tim?  Anyone?
>>
>>
>> Jennifer
>>
>> -----Original Message-----
>> From: Riccardo Tasso [mailto:ta...@el...] Sent: Monday,
January
>> 11, 2010 8:47 AM
>> To: ng4...@li...
>> Subject: [namedgraphs] Problem related to Jena 2.6.0
>>
>> Hi everybody,
>>    I'm starting a project using NG4J and I'm currently using the
lastest
>> version (0.9.2) which is based on Jena 2.6.0. In these days I tried to
>> validate a RDF dataset with a RDF Schema but it gives me problems with
Jena
>> 2.6.0 but it works ok with Jena 2.6.2. Is it possible to update the
NG4J
>> making it use Jena 2.6.0?
>>
>> If you like I could get more specific about my problem, but I'm pretty
>> sure it regards more Jena than NG4J.
>>
>> Thanks,
>>    Riccardo
>>
>>
--------------------------------------------------------------------------
>> ----
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>> Take advantage of Verizon's best-in-class app development support
>> A streamlined, 14 day to market process makes app distribution fast and
>> easy
>> Join now and get one step closer to millions of Verizon customers
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>>
>
>
>

Re: [namedgraphs] Problem related to Jena 2.6.0

[Riccardo T. <ta...@el...>]

Thank you Jennifer,
    I'm really interested in the possibilities which named graphs could 
offer to my project. In the next days I'll try to import in Eclipse the 
NG4J source and to update Jena libraries to see if it's immediate. Then 
I'll make you know my results.

Riccardo

Jennifer Cormier ha scritto:
> Hi Riccardo,
>
> It's great to hear you are using to NG4J!  Sorry that its version of Jena
> seems to be causing problems.
>
> Last summer Tim Pizey had NG4J working locally against a
> pre-Jena-2.6.2-snapshot.  I don't know whether anyone has worked on that
> since.
>
> Tim?  Anyone?
>
>
> Jennifer
>  
>
> -----Original Message-----
> From: Riccardo Tasso [mailto:ta...@el...] 
> Sent: Monday, January 11, 2010 8:47 AM
> To: ng4...@li...
> Subject: [namedgraphs] Problem related to Jena 2.6.0
>
> Hi everybody,
>     I'm starting a project using NG4J and I'm currently using the 
> lastest version (0.9.2) which is based on Jena 2.6.0. In these days I 
> tried to validate a RDF dataset with a RDF Schema but it gives me 
> problems with Jena 2.6.0 but it works ok with Jena 2.6.2. Is it possible 
> to update the NG4J making it use Jena 2.6.0?
>
> If you like I could get more specific about my problem, but I'm pretty 
> sure it regards more Jena than NG4J.
>
> Thanks,
>     Riccardo
>
> --------------------------------------------------------------------------
> ----
> This SF.Net email is sponsored by the Verizon Developer Community
> Take advantage of Verizon's best-in-class app development support
> A streamlined, 14 day to market process makes app distribution fast and
> easy
> Join now and get one step closer to millions of Verizon customers
> http://p.sf.net/sfu/verizon-dev2dev 
> _______________________________________________
> ng4j-namedgraphs mailing list
> ng4...@li...
> https://lists.sourceforge.net/lists/listinfo/ng4j-namedgraphs
>   

Re: [namedgraphs] Problem related to Jena 2.6.0

[Jennifer C. <jen...@at...>]

Hi Riccardo,

It's great to hear you are using to NG4J!  Sorry that its version of Jena
seems to be causing problems.

Last summer Tim Pizey had NG4J working locally against a
pre-Jena-2.6.2-snapshot.  I don't know whether anyone has worked on that
since.

Tim?  Anyone?


Jennifer
 

-----Original Message-----
From: Riccardo Tasso [mailto:ta...@el...] 
Sent: Monday, January 11, 2010 8:47 AM
To: ng4...@li...
Subject: [namedgraphs] Problem related to Jena 2.6.0

Hi everybody,
    I'm starting a project using NG4J and I'm currently using the 
lastest version (0.9.2) which is based on Jena 2.6.0. In these days I 
tried to validate a RDF dataset with a RDF Schema but it gives me 
problems with Jena 2.6.0 but it works ok with Jena 2.6.2. Is it possible 
to update the NG4J making it use Jena 2.6.0?

If you like I could get more specific about my problem, but I'm pretty 
sure it regards more Jena than NG4J.

Thanks,
    Riccardo

--------------------------------------------------------------------------
----
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Take advantage of Verizon's best-in-class app development support
A streamlined, 14 day to market process makes app distribution fast and
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Join now and get one step closer to millions of Verizon customers
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_______________________________________________
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https://lists.sourceforge.net/lists/listinfo/ng4j-namedgraphs

[namedgraphs] Problem related to Jena 2.6.0

[Riccardo T. <ta...@el...>]

Hi everybody,
    I'm starting a project using NG4J and I'm currently using the 
lastest version (0.9.2) which is based on Jena 2.6.0. In these days I 
tried to validate a RDF dataset with a RDF Schema but it gives me 
problems with Jena 2.6.0 but it works ok with Jena 2.6.2. Is it possible 
to update the NG4J making it use Jena 2.6.0?

If you like I could get more specific about my problem, but I'm pretty 
sure it regards more Jena than NG4J.

Thanks,
    Riccardo

[namedgraphs] Persisting a TRIG file multiple times

[Arun R. <rao...@gm...>]

Hi,

I was trying to read a TRIG file multiple times into memory and then write
it back without making changes and I ran into errors with the parser.

Here is the sample code:

        String filename = "test.trig";
        NamedGraphSet graphSet = new NamedGraphSetImpl();
        NamedGraphModel ngModel = new NamedGraphModel(graphSet, "");
        InputStream in = FileManager.get().open(filename);
        if (in == null) {
            throw new IllegalArgumentException("File: not found");
        }

        graphSet.read(in, "TRIG", null);

        try {
            ngModel.write(new PrintWriter(new File(filename)), "TRIG");
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

test.trig:

@prefix ns0:     <http://example.com/> .

<http://graph1.com/> {ns0:aResource
          ns0:pProperty ns0:bResource ;
          ns0:qProperty ns0:xResource .
}

The first run, it creates an extra line:

<> {} in the TRIG file

The second run, it creates an extra line:

<null> {} in the TRIG file

The third run fails.

If however, I change:
graphSet.read(in, "TRIG", null);

to:
graphSet.read(in, "TRIG", "");

it works fine.

What could be the issue? Is this a bug?

Regards,
Arun

Re: [namedgraphs] Problems with getting raw named graph model from InfModel

[Olaf H. <ha...@in...>]

Hey,

On Friday 20 November 2009 06:50:37 Arun Rao wrote:
> [...]
> > > I am trying to create an InfModel object using a NG4J NamedGraphModel
> > > and when I get the raw model from the InfModel, I expect to get back
> > > the original NamedGraphModel.
> >
> > So? Do you get it?
> > (i.e. is infModel.getRawModel() an instance of NamedGraphModel?)
> 
> No, and that's the issue.
> 
> Here is some code:
> System.out.println("rawModel instanceof NamedGraphModel?: ");
> System.out.println(infModel.getRawModel() instanceof NamedGraphModel);
> NamedGraphSet ngSet = ((NamedGraphModel)
> infModel.getRawModel()).getNamedGraphSet();
> 
> Output:
> rawModel instanceof NamedGraphModel?:
> false
> java.lang.ClassCastException: com.hp.hpl.jena.rdf.model.impl.ModelCom
>  cannot be cast to de.fuberlin.wiwiss.ng4j.NamedGraphModel
>     at com.test.NG4JTest.main(NG4JTest.java:52)

Okay, after digging a bit into the Jena code I see the problem. Their 
implementation of the InfModel interface does not store the base model but it 
stores the graph of the base model (i.e. the object returned by the 'getGraph' 
method of the base model). Each call to 'getRawModel()' creates a new model 
from the stored base graph.
The problem is that 'getGraph' of a NamedGraphModel returns a union of all 
named graphs in the NamedGraphSet the NamedGraphModel is based on. The class 
that represents this union is an internal class -as you already experienced- 
for which there is no possibility to come back to the NamedGraphSet.
Hence, unfortunately, the only possibility to get back the original 
NamedGraphSet is to keep it seperately. You could create your own InfModel 
class (derived from Jena's InfModelImpl) and keep the reference to the 
NamedGraphSet there.

Olaf

Re: [namedgraphs] Problems with getting raw named graph model from InfModel

[Arun R. <rao...@gm...>]

Hi Olaf,

On Thu, Nov 19, 2009 at 2:59 PM, Olaf Hartig <ha...@in...
> wrote:

> Hey,
>
> On Thursday 19 November 2009 08:57:26 Arun Rao wrote:
> > Hi,
> >
> > I am trying to create an InfModel object using a NG4J NamedGraphModel and
> > when I get the raw model from the InfModel, I expect to get back the
> > original NamedGraphModel.
>
> So? Do you get it?
> (i.e. is infModel.getRawModel() an instance of NamedGraphModel?)
>

No, and that's the issue.

Here is some code:
System.out.println("rawModel instanceof NamedGraphModel?: ");
System.out.println(infModel.getRawModel() instanceof NamedGraphModel);
NamedGraphSet ngSet = ((NamedGraphModel)
infModel.getRawModel()).getNamedGraphSet();

Output:
rawModel instanceof NamedGraphModel?:
false
java.lang.ClassCastException: com.hp.hpl.jena.rdf.model.impl.ModelCom cannot
be cast to de.fuberlin.wiwiss.ng4j.NamedGraphModel
    at com.test.NG4JTest.main(NG4JTest.java:52)


>
> > While this comparison returns true:
> > infModel.getRawModel().equals(ngModel)
> >
> > I am not able to cast infModel.getRawModel().getGraph() to NamedGraphSet
> > since infModel.getRawModel().getGraph() seems to be an instance of an
> inner
> > class of NamedGraphSetImpl.
>
> That's true.
>
> > There does not seem to be a simple way in which I can get NamedGraphModel
> > back.
>
> I would expect you get the NamedGraphModel by calling getRawModel() - at
> least
> that's what the Jena Javadoc says.
>
> The problem seems to be (I assume based on your use of the getGraph()
> method)
> that you are not interested in the NamedGraphModel that backs the infModel
> but
> you are interested in the NamedGraphSet that backs the NamedGraphModel.
> Right?
> If so, you should be able to call
>
> ( (NamedGraphModel) infModel.getRawModel() ).getNamedGraphSet()
>

Frankly, either would do. All I want is a way to get back the provenance
information.


>
> Greetings,
> Olaf
>
>
> ------------------------------------------------------------------------------
> Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day
> trial. Simplify your report design, integration and deployment - and focus
> on
> what you do best, core application coding. Discover what's new with
> Crystal Reports now.  http://p.sf.net/sfu/bobj-july
> _______________________________________________
> ng4j-namedgraphs mailing list
> ng4...@li...
> https://lists.sourceforge.net/lists/listinfo/ng4j-namedgraphs
>

Thanks,
Arun

Re: [namedgraphs] Problems with getting raw named graph model from InfModel

[Olaf H. <ha...@in...>]

Hey,

On Thursday 19 November 2009 08:57:26 Arun Rao wrote:
> Hi,
> 
> I am trying to create an InfModel object using a NG4J NamedGraphModel and
> when I get the raw model from the InfModel, I expect to get back the
> original NamedGraphModel.

So? Do you get it?
(i.e. is infModel.getRawModel() an instance of NamedGraphModel?)

> While this comparison returns true:
> infModel.getRawModel().equals(ngModel)
> 
> I am not able to cast infModel.getRawModel().getGraph() to NamedGraphSet
> since infModel.getRawModel().getGraph() seems to be an instance of an inner
> class of NamedGraphSetImpl.

That's true.

> There does not seem to be a simple way in which I can get NamedGraphModel
> back.

I would expect you get the NamedGraphModel by calling getRawModel() - at least 
that's what the Jena Javadoc says.

The problem seems to be (I assume based on your use of the getGraph() method) 
that you are not interested in the NamedGraphModel that backs the infModel but 
you are interested in the NamedGraphSet that backs the NamedGraphModel. Right?
If so, you should be able to call 

( (NamedGraphModel) infModel.getRawModel() ).getNamedGraphSet()

Greetings,
Olaf

[namedgraphs] Problems with getting raw named graph model from InfModel

[Arun R. <rao...@gm...>]

Hi,

I am trying to create an InfModel object using a NG4J NamedGraphModel and
when I get the raw model from the InfModel, I expect to get back the
original NamedGraphModel.

While this comparison returns true:
infModel.getRawModel().equals(
ngModel)

I am not able to cast
infModel.getRawModel().getGraph() to NamedGraphSet since
infModel.getRawModel().getGraph() seems to be an instance of an inner class
of NamedGraphSetImpl.

There does not seem to be a simple way in which I can get NamedGraphModel
back.

Is there a way in which I can get hold of the NamedGraphModel so that I can
just keep the InfModel in memory and discard the other objects and still
have provenance?

Regards,
Arun Rao

Re: [namedgraphs] NamedGraphSet to extend Iterable

[Olaf H. <ha...@in...>]

Hey Tim,

On Friday 25 September 2009 16:33:45 Tim Pizey wrote:
> Hi,
>
> for convenience would it be nice for NamedGraphSet to extend Iterable?
>
> It is trivial:
>
>   public Iterator<NamedGraph> iterator() {
>     return listGraphs();
>   }

Yes, why not

> though puting it in NamedGraphSetIO might be a bit ugly.

I wouldn't put it in NamedGraphSetIO but in the classes that implement methods 
of the interface that are related to the "set nature" of NamedGraphSet.

Olaf

[namedgraphs] NamedGraphSet to extend Iterable

[Tim P. <tim...@ou...>]

Hi, 

for convenience would it be nice for NamedGraphSet to extend Iterable?

It is trivial: 

  public Iterator<NamedGraph> iterator() {
    return listGraphs();
  }

though puting it in NamedGraphSetIO might be a bit ugly. 


Tim

Re: [namedgraphs] Base64 encoding

[Jennifer C. <jen...@at...>]

Thank you, Tim.  I should have run the tests locally before submitting.
Thanks for catching that omission!

Jennifer


-----Original Message-----
From: Tim Pizey [mailto:tim...@ou...] 
Sent: Tuesday, September 22, 2009 4:54 AM
To: ng4...@li...
Subject: Re: [namedgraphs] Base64 encoding

Hi Jennifer, 

I do not know the requirement here, but the tests reflected  what was done
previously. 
I have now corrected the tests to reflect your change. 

I now have ng4j running under Hudson, unfortunately not on a public url,
so I was alerted when the tests failed. 

yours
Tim






On Thursday 17 Sep 2009 20:50:09 Jennifer Cormier wrote:
> Hi everyone,
> 
> The Base64 encoding is working slightly different since the change 
> away from the sun libraries.  (Note: I have no issues with the change, 
> and thank Tim for making it!  We needed to move away from those libs.)
> 
> If you run the SWPExample (in src/de.fuberlin.wiwiss.ng4j.examples) 
> and compare the functionality from the prior release, it can be seen 
> that the sun libraries didn't chunk the data when encoding.  (i.e. no 
> carriage return is added after 76 characters.)
> 
> The new code (e.g. in SWPSignatureUtilities.calculateDigest) is using 
> Base64.encodeBase64Chunked so it does insert the carriage return.
> 
> >From what I've read, it's actually standard to include the carriage
> return.
> 
> HOWEVER I'm not sure we want to do that for the digest in NG4J.  The 
> digest is then added to the warrantGraph as a literal (as the object 
> in an RDF statement about the digest).  Perhaps that's legal, but it 
> does look odd when the RDF is written in whatever format.
> 
> I'm assuming that change was made unintentionally and we could go back 
> to the chunk-less style?  i.e. change to use Base64.encodeBase64 in 
> all places?
> 
> Jennifer
> 
> Jennifer P. Cormier
> Sr. Computer Scientist
> ATC-NY
> www.atc-nycorp.com
>   
> 
> ----------------------------------------------------------------------
> -------- Come build with us! The BlackBerry® Developer Conference 
> in SF, CA is the only developer event you need to attend this year. 
> Jumpstart your developing skills, take BlackBerry mobile applications 
> to market and stay ahead of the curve. Join us from November 9-12, 
> 2009. Register now! http://p.sf.net/sfu/devconf 
> _______________________________________________
> ng4j-namedgraphs mailing list
> ng4...@li...
> https://lists.sourceforge.net/lists/listinfo/ng4j-namedgraphs
> 

--------------------------------------------------------------------------
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the only developer event you need to attend this year. Jumpstart your
developing skills, take BlackBerry mobile applications to market and stay
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Re: [namedgraphs] Base64 encoding

[Tim P. <tim...@ou...>]

Hi Jennifer, 

I do not know the requirement here, but the tests reflected  what was done previously. 
I have now corrected the tests to reflect your change. 

I now have ng4j running under Hudson, unfortunately not on a public url, so I was alerted when the tests failed. 

yours
Tim






On Thursday 17 Sep 2009 20:50:09 Jennifer Cormier wrote:
> Hi everyone,
> 
> The Base64 encoding is working slightly different since the change away
> from the sun libraries.  (Note: I have no issues with the change, and
> thank Tim for making it!  We needed to move away from those libs.)
> 
> If you run the SWPExample (in src/de.fuberlin.wiwiss.ng4j.examples) and
> compare the functionality from the prior release, it can be seen that the
> sun libraries didn't chunk the data when encoding.  (i.e. no carriage
> return is added after 76 characters.)
> 
> The new code (e.g. in SWPSignatureUtilities.calculateDigest) is using
> Base64.encodeBase64Chunked so it does insert the carriage return.
> 
> >From what I've read, it's actually standard to include the carriage
> return.
> 
> HOWEVER I'm not sure we want to do that for the digest in NG4J.  The
> digest is then added to the warrantGraph as a literal (as the object in an
> RDF statement about the digest).  Perhaps that's legal, but it does look
> odd when the RDF is written in whatever format.
> 
> I'm assuming that change was made unintentionally and we could go back to
> the chunk-less style?  i.e. change to use Base64.encodeBase64 in all
> places?
> 
> Jennifer
> 
> Jennifer P. Cormier
> Sr. Computer Scientist
> ATC-NY
> www.atc-nycorp.com
>   
> 
> ------------------------------------------------------------------------------
> Come build with us! The BlackBerry® Developer Conference in SF, CA
> is the only developer event you need to attend this year. Jumpstart your
> developing skills, take BlackBerry mobile applications to market and stay 
> ahead of the curve. Join us from November 9-12, 2009. Register now!
> http://p.sf.net/sfu/devconf
> _______________________________________________
> ng4j-namedgraphs mailing list
> ng4...@li...
> https://lists.sourceforge.net/lists/listinfo/ng4j-namedgraphs
> 

Re: [namedgraphs] Base64 encoding

[Jennifer C. <jen...@at...>]

Hi Tim,

Thank you for confirming that.  And thanks again for all your hard work to
move NG4J to current libraries!

Hearing nothing else yet I went ahead and committed the proposed change to
no longer chunk digests.  (If there's a reason to chunk digests then we
can re-visit this and make further modifications before the next release -
just let us know.)
 
Jennifer


-----Original Message-----
From: Tim Pizey [mailto:tim...@ou...] 
Sent: Friday, September 18, 2009 4:03 PM
To: ng4...@li...
Subject: Re: [namedgraphs] Base64 encoding

Hi Jennifer,

The change was, indeed, made on a best guess basis, only motivated by
removing warnings from the build, so please do as you see fit. 

yours
Tim


On Thursday 17 September 2009 20:50:09 Jennifer Cormier wrote:
> Hi everyone,
> 
> The Base64 encoding is working slightly different since the change 
> away from the sun libraries.  (Note: I have no issues with the change, 
> and thank Tim for making it!  We needed to move away from those libs.)
> 
> If you run the SWPExample (in src/de.fuberlin.wiwiss.ng4j.examples) 
> and compare the functionality from the prior release, it can be seen 
> that the sun libraries didn't chunk the data when encoding.  (i.e. no 
> carriage return is added after 76 characters.)
> 
> The new code (e.g. in SWPSignatureUtilities.calculateDigest) is using 
> Base64.encodeBase64Chunked so it does insert the carriage return.
> 
> >From what I've read, it's actually standard to include the carriage
> return.
> 
> HOWEVER I'm not sure we want to do that for the digest in NG4J.  The 
> digest is then added to the warrantGraph as a literal (as the object 
> in an RDF statement about the digest).  Perhaps that's legal, but it 
> does look odd when the RDF is written in whatever format.
> 
> I'm assuming that change was made unintentionally and we could go back 
> to the chunk-less style?  i.e. change to use Base64.encodeBase64 in 
> all places?
> 
> Jennifer
> 
> Jennifer P. Cormier
> Sr. Computer Scientist
> ATC-NY
> www.atc-nycorp.com