You are viewing a plain text version of this content. The canonical link for it is here.
Posted to users@jena.apache.org by Andy Seaborne <an...@apache.org> on 2012/10/27 00:19:00 UTC
Re: ARQNotImplemented exception thrown by ARQ function calls
Oversight - I've just implemented it (it's not hard!). It wil be in
tonight's snapshot build of 2.7.5-SNAPSHOT (it builds at about 05:00 UTC)
https://repository.apache.org/content/repositories/snapshots/org/apache/jena/apache-jena/
By the way, you can execute algebra expressions directly:
DatasetGraph dsg = ...
QueryIterator qIter = Algebra.exec(op, dsg) ;
Not all algebra expressions can be turned into a query. If you are
manipulating the algebra, you can create forms OpAsQuery does not recognize.
Andy
On 26/10/12 22:24, John Liu wrote:
> I use some Jena arq apis to modify the query for adding filter in runtime.
>
> The query is
>
> PREFIX geo: <http://www.w3.org/2003/01/geo/wgs84_pos#>
> PREFIX onto: <http://dbpedia.org/ontology/>
> SELECT * WHERE {
> ?p a onto:Place .
> ?p geo:l* ?loc .
> }
>
> There is valid card in the line "?p geo:l* ?loc ."
>
> The funcations I used are:
>
> AlgebraGenerator ag = new AlgebraGenerator();
> Op op = ag.compile(query);
> op = OpFilter.filter(e, op);
> Query query2 = OpAsQuery.asQuery(op);
>
> This query causes an ARQNotImplemented exception thrown in the last function call. The exception stack trace is:
>
> com.hp.hpl.jena.sparql.ARQNotImplemented error occurred when handling the REST data service.
> Not implemented: OpPath
> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.visit(OpAsQuery.java:224)
> at com.hp.hpl.jena.sparql.algebra.op.OpPath.visit(OpPath.java:73)
> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.asElementGroup(OpAsQuery.java:97)
> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.asElement(OpAsQuery.java:88)
> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.visit(OpAsQuery.java:168)
> at com.hp.hpl.jena.sparql.algebra.op.OpSequence.visit(OpSequence.java:75)
> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.visit(OpAsQuery.java:473)
> at com.hp.hpl.jena.sparql.algebra.op.OpSlice.visit(OpSlice.java:50)
> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.asElementGroup(OpAsQuery.java:97)
> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.asElement(OpAsQuery.java:88)
> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.visit(OpAsQuery.java:310)
> at com.hp.hpl.jena.sparql.algebra.op.OpFilter.visit(OpFilter.java:110)
> at com.hp.hpl.jena.sparql.algebra.OpAsQuery.asQuery(OpAsQuery.java:50)
>
> The arq library I used is jena-arq-2.9.1 and the jean is jena-core-2.7.1
>
> My question is if this is bug in the arq functions? I have tested these functions without adding the filter(the third call), but it still throws the exception.
>
> If it isa bug, how can I file a defect to it?
>
> If it is not, how can I fix my code to avoid this exception.
>
> Thanks a lot for your help.
>
> John
>
Re: ARQNotImplemented exception thrown by ARQ function calls
Posted by Andy Seaborne <an...@apache.org>.
>> If it isa bug, how can I file a defect to it?
PS:
The issue tracker is here:
https://issues.apache.org/jira/browse/JENA
for both reports and sending patches.
Andy
Re: ARQNotImplemented exception thrown by ARQ function calls
Posted by John Liu <jo...@yahoo.com>.
Thanks Andy, for your detailed answers.
> Do you need to turn it back into query syntax? You can directly execute
> the algebra after modification.
Yes, I need to send the query to an endpoint after adding some filters.
John
________________________________
From: Andy Seaborne <an...@apache.org>
To: users@jena.apache.org
Sent: Monday, October 29, 2012 4:43:55 PM
Subject: Re: ARQNotImplemented exception thrown by ARQ function calls
On 29/10/12 16:31, John Liu wrote:
> Thank you very much Andy for your quick action.
>
>> It will be in tonight's snapshot build of 2.7.5-SNAPSHOT (it builds at about 05:00 UTC)
>
> When will Jena 2.7.5 be released?
We have just release 2.7.4 so not immediately.
We do, as a project, practice de facto, "green trunk" i.e. the trunk is
in a state to be released (svn code trunk and nightly build, which is a
build of trunk). The code even stamps the exact snapshot build and
build timestamp to identify precisely which code it is.
>
>> Not all algebra expressions can be turned into a query. If you are
>> manipulating the algebra, you can create forms OpAsQuery does not recognize.
>
> Can I assume that all ops which are compiled from a sparql query can
be turned back to a sparql query? For example, the following codes are
always working fine:
Yes but test. The idea is any valid query will be reversed into an
equivalent query (equivalent => same answers ; it may not test .equals
with the input - surface details have been lost in the algebra). It is
a pragmatic reconstruction of an equivalent query, not a theoretically
proven process.
>
> AlgebraGenerator ag = new AlgebraGenerator();
> Op op = ag.compile(query);
Op op = Algebra.compile(query) ;
> Query query2 = OpAsQuery.asQuery(op);
>
>
> The reason why we use these functions is that we want to add filters
> into the query in runtime, for example modifying the op by adding a
> filter expression (op = OpFilter.filter(e, op);), is this the best
> way to do that(adding a filter)?
Do you need to turn it back into query syntax? You can directly execute
the algebra after modification.
Andy
>
> Thanks, John
>
>
>
>
> ________________________________
> From: Andy Seaborne <an...@apache.org>
> To: users@jena.apache.org
> Sent: Friday, October 26, 2012 6:19:00 PM
> Subject: Re: ARQNotImplemented exception thrown by ARQ function calls
>
> Oversight - I've just implemented it (it's not hard!). It wil be in
> tonight's snapshot build of 2.7.5-SNAPSHOT (it builds at about 05:00 UTC)
>
> https://repository.apache.org/content/repositories/snapshots/org/apache/jena/apache-jena/
>
> By the way, you can execute algebra expressions directly:
>
> DatasetGraph dsg = ...
> QueryIterator qIter = Algebra.exec(op, dsg) ;
>
> Not all algebra expressions can be turned into a query. If you are
> manipulating the algebra, you can create forms OpAsQuery does not recognize.
>
> Andy
>
> On 26/10/12 22:24, John Liu wrote:
>> I use some Jena arq apis to modify the query for adding filter in runtime.
>>
>> The query is
>>
>> PREFIX geo: <http://www.w3.org/2003/01/geo/wgs84_pos#>
>> PREFIX onto: <http://dbpedia.org/ontology/>
>> SELECT * WHERE {
>> ?p a onto:Place .
>> ?p geo:l* ?loc .
>> }
>>
>> There is valid card in the line "?p geo:l* ?loc ."
>>
>> The funcations I used are:
>>
>> AlgebraGenerator ag = new AlgebraGenerator();
>> Op op = ag.compile(query);
>> op = OpFilter.filter(e, op);
>> Query query2 = OpAsQuery.asQuery(op);
>>
>> This query causes an ARQNotImplemented exception thrown in the last function call. The exception stack trace is:
>>
>> com.hp.hpl.jena.sparql.ARQNotImplemented error occurred when handling the REST data service.
>> Not implemented: OpPath
>> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.visit(OpAsQuery.java:224)
>> at com.hp.hpl.jena.sparql.algebra.op.OpPath.visit(OpPath.java:73)
>> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.asElementGroup(OpAsQuery.java:97)
>> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.asElement(OpAsQuery.java:88)
>> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.visit(OpAsQuery.java:168)
>> at com.hp.hpl.jena.sparql.algebra.op.OpSequence.visit(OpSequence.java:75)
>> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.visit(OpAsQuery.java:473)
>> at com.hp.hpl.jena.sparql.algebra.op.OpSlice.visit(OpSlice.java:50)
>> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.asElementGroup(OpAsQuery.java:97)
>> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.asElement(OpAsQuery.java:88)
>> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.visit(OpAsQuery.java:310)
>> at com.hp.hpl.jena.sparql.algebra.op.OpFilter.visit(OpFilter.java:110)
>> at com.hp.hpl.jena.sparql.algebra.OpAsQuery.asQuery(OpAsQuery.java:50)
>>
>> The arq library I used is jena-arq-2.9.1 and the jean is jena-core-2.7.1
>>
>> My question is if this is bug in the arq functions? I have tested these functions without adding the filter(the third call), but it still throws the exception.
>>
>> If it isa bug, how can I file a defect to it?
>>
>> If it is not, how can I fix my code to avoid this exception.
>>
>> Thanks a lot for your help.
>>
>> John
>>
Re: ARQNotImplemented exception thrown by ARQ function calls
Posted by Andy Seaborne <an...@apache.org>.
On 29/10/12 16:31, John Liu wrote:
> Thank you very much Andy for your quick action.
>
>> It will be in tonight's snapshot build of 2.7.5-SNAPSHOT (it builds at about 05:00 UTC)
>
> When will Jena 2.7.5 be released?
We have just release 2.7.4 so not immediately.
We do, as a project, practice de facto, "green trunk" i.e. the trunk is
in a state to be released (svn code trunk and nightly build, which is a
build of trunk). The code even stamps the exact snapshot build and
build timestamp to identify precisely which code it is.
>
>> Not all algebra expressions can be turned into a query. If you are
>> manipulating the algebra, you can create forms OpAsQuery does not recognize.
>
> Can I assume that all ops which are compiled from a sparql query can
be turned back to a sparql query? For example, the following codes are
always working fine:
Yes but test. The idea is any valid query will be reversed into an
equivalent query (equivalent => same answers ; it may not test .equals
with the input - surface details have been lost in the algebra). It is
a pragmatic reconstruction of an equivalent query, not a theoretically
proven process.
>
> AlgebraGenerator ag = new AlgebraGenerator();
> Op op = ag.compile(query);
Op op = Algebra.compile(query) ;
> Query query2 = OpAsQuery.asQuery(op);
>
>
> The reason why we use these functions is that we want to add filters
> into the query in runtime, for example modifying the op by adding a
> filter expression (op = OpFilter.filter(e, op);), is this the best
> way to do that(adding a filter)?
Do you need to turn it back into query syntax? You can directly execute
the algebra after modification.
Andy
>
> Thanks, John
>
>
>
>
> ________________________________
> From: Andy Seaborne <an...@apache.org>
> To: users@jena.apache.org
> Sent: Friday, October 26, 2012 6:19:00 PM
> Subject: Re: ARQNotImplemented exception thrown by ARQ function calls
>
> Oversight - I've just implemented it (it's not hard!). It wil be in
> tonight's snapshot build of 2.7.5-SNAPSHOT (it builds at about 05:00 UTC)
>
> https://repository.apache.org/content/repositories/snapshots/org/apache/jena/apache-jena/
>
> By the way, you can execute algebra expressions directly:
>
> DatasetGraph dsg = ...
> QueryIterator qIter = Algebra.exec(op, dsg) ;
>
> Not all algebra expressions can be turned into a query. If you are
> manipulating the algebra, you can create forms OpAsQuery does not recognize.
>
> Andy
>
> On 26/10/12 22:24, John Liu wrote:
>> I use some Jena arq apis to modify the query for adding filter in runtime.
>>
>> The query is
>>
>> PREFIX geo: <http://www.w3.org/2003/01/geo/wgs84_pos#>
>> PREFIX onto: <http://dbpedia.org/ontology/>
>> SELECT * WHERE {
>> ?p a onto:Place .
>> ?p geo:l* ?loc .
>> }
>>
>> There is valid card in the line "?p geo:l* ?loc ."
>>
>> The funcations I used are:
>>
>> AlgebraGenerator ag = new AlgebraGenerator();
>> Op op = ag.compile(query);
>> op = OpFilter.filter(e, op);
>> Query query2 = OpAsQuery.asQuery(op);
>>
>> This query causes an ARQNotImplemented exception thrown in the last function call. The exception stack trace is:
>>
>> com.hp.hpl.jena.sparql.ARQNotImplemented error occurred when handling the REST data service.
>> Not implemented: OpPath
>> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.visit(OpAsQuery.java:224)
>> at com.hp.hpl.jena.sparql.algebra.op.OpPath.visit(OpPath.java:73)
>> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.asElementGroup(OpAsQuery.java:97)
>> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.asElement(OpAsQuery.java:88)
>> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.visit(OpAsQuery.java:168)
>> at com.hp.hpl.jena.sparql.algebra.op.OpSequence.visit(OpSequence.java:75)
>> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.visit(OpAsQuery.java:473)
>> at com.hp.hpl.jena.sparql.algebra.op.OpSlice.visit(OpSlice.java:50)
>> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.asElementGroup(OpAsQuery.java:97)
>> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.asElement(OpAsQuery.java:88)
>> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.visit(OpAsQuery.java:310)
>> at com.hp.hpl.jena.sparql.algebra.op.OpFilter.visit(OpFilter.java:110)
>> at com.hp.hpl.jena.sparql.algebra.OpAsQuery.asQuery(OpAsQuery.java:50)
>>
>> The arq library I used is jena-arq-2.9.1 and the jean is jena-core-2.7.1
>>
>> My question is if this is bug in the arq functions? I have tested these functions without adding the filter(the third call), but it still throws the exception.
>>
>> If it isa bug, how can I file a defect to it?
>>
>> If it is not, how can I fix my code to avoid this exception.
>>
>> Thanks a lot for your help.
>>
>> John
>>
Re: ARQNotImplemented exception thrown by ARQ function calls
Posted by Martynas Jusevičius <ma...@graphity.org>.
There's another way to modify queries dynamically - as RDF using SPIN
vocabulary:
http://www.w3.org/Submission/2011/SUBM-spin-modeling-20110222/
Example QueryBuilder class:
https://github.com/Graphity/graphity-ldp/blob/master/src/main/java/org/graphity/util/QueryBuilder.java
Martynas
graphity.org
On Mon, Oct 29, 2012 at 6:31 PM, John Liu <jo...@yahoo.com> wrote:
> Thank you very much Andy for your quick action.
>
>>It will be in tonight's snapshot build of 2.7.5-SNAPSHOT (it builds at about 05:00 UTC)
>
> When will Jena 2.7.5 be released?
>
>>Not all algebra expressions can be turned into a query. If you are
>>manipulating the algebra, you can create forms OpAsQuery does not recognize.
>
> Can I assume that all ops which are compiled from a sparql query can be turned back to a sparql query? For example, the following codes are always working fine:
>
> AlgebraGenerator ag = new AlgebraGenerator();
> Op op = ag.compile(query);
> Query query2 = OpAsQuery.asQuery(op);
>
>
> The reason why we use these functions is that we want to add filters into the query in runtime, for example modifying the op by adding a filter expression (op = OpFilter.filter(e, op);), is this the best way to do that(adding a filter)?
>
> Thanks, John
>
>
>
>
> ________________________________
> From: Andy Seaborne <an...@apache.org>
> To: users@jena.apache.org
> Sent: Friday, October 26, 2012 6:19:00 PM
> Subject: Re: ARQNotImplemented exception thrown by ARQ function calls
>
> Oversight - I've just implemented it (it's not hard!). It wil be in
> tonight's snapshot build of 2.7.5-SNAPSHOT (it builds at about 05:00 UTC)
>
> https://repository.apache.org/content/repositories/snapshots/org/apache/jena/apache-jena/
>
> By the way, you can execute algebra expressions directly:
>
> DatasetGraph dsg = ...
> QueryIterator qIter = Algebra.exec(op, dsg) ;
>
> Not all algebra expressions can be turned into a query. If you are
> manipulating the algebra, you can create forms OpAsQuery does not recognize.
>
> Andy
>
> On 26/10/12 22:24, John Liu wrote:
>> I use some Jena arq apis to modify the query for adding filter in runtime.
>>
>> The query is
>>
>> PREFIX geo: <http://www.w3.org/2003/01/geo/wgs84_pos#>
>> PREFIX onto: <http://dbpedia.org/ontology/>
>> SELECT * WHERE {
>> ?p a onto:Place .
>> ?p geo:l* ?loc .
>> }
>>
>> There is valid card in the line "?p geo:l* ?loc ."
>>
>> The funcations I used are:
>>
>> AlgebraGenerator ag = new AlgebraGenerator();
>> Op op = ag.compile(query);
>> op = OpFilter.filter(e, op);
>> Query query2 = OpAsQuery.asQuery(op);
>>
>> This query causes an ARQNotImplemented exception thrown in the last function call. The exception stack trace is:
>>
>> com.hp.hpl.jena.sparql.ARQNotImplemented error occurred when handling the REST data service.
>> Not implemented: OpPath
>> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.visit(OpAsQuery.java:224)
>> at com.hp.hpl.jena.sparql.algebra.op.OpPath.visit(OpPath.java:73)
>> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.asElementGroup(OpAsQuery.java:97)
>> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.asElement(OpAsQuery.java:88)
>> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.visit(OpAsQuery.java:168)
>> at com.hp.hpl.jena.sparql.algebra.op.OpSequence.visit(OpSequence.java:75)
>> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.visit(OpAsQuery.java:473)
>> at com.hp.hpl.jena.sparql.algebra.op.OpSlice.visit(OpSlice.java:50)
>> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.asElementGroup(OpAsQuery.java:97)
>> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.asElement(OpAsQuery.java:88)
>> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.visit(OpAsQuery.java:310)
>> at com.hp.hpl.jena.sparql.algebra.op.OpFilter.visit(OpFilter.java:110)
>> at com.hp.hpl.jena.sparql.algebra.OpAsQuery.asQuery(OpAsQuery.java:50)
>>
>> The arq library I used is jena-arq-2.9.1 and the jean is jena-core-2.7.1
>>
>> My question is if this is bug in the arq functions? I have tested these functions without adding the filter(the third call), but it still throws the exception.
>>
>> If it isa bug, how can I file a defect to it?
>>
>> If it is not, how can I fix my code to avoid this exception.
>>
>> Thanks a lot for your help.
>>
>> John
>>
Re: ARQNotImplemented exception thrown by ARQ function calls
Posted by John Liu <jo...@yahoo.com>.
Thank you very much Andy for your quick action.
>It will be in tonight's snapshot build of 2.7.5-SNAPSHOT (it builds at about 05:00 UTC)
When will Jena 2.7.5 be released?
>Not all algebra expressions can be turned into a query. If you are
>manipulating the algebra, you can create forms OpAsQuery does not recognize.
Can I assume that all ops which are compiled from a sparql query can be turned back to a sparql query? For example, the following codes are always working fine:
AlgebraGenerator ag = new AlgebraGenerator();
Op op = ag.compile(query);
Query query2 = OpAsQuery.asQuery(op);
The reason why we use these functions is that we want to add filters into the query in runtime, for example modifying the op by adding a filter expression (op = OpFilter.filter(e, op);), is this the best way to do that(adding a filter)?
Thanks, John
________________________________
From: Andy Seaborne <an...@apache.org>
To: users@jena.apache.org
Sent: Friday, October 26, 2012 6:19:00 PM
Subject: Re: ARQNotImplemented exception thrown by ARQ function calls
Oversight - I've just implemented it (it's not hard!). It wil be in
tonight's snapshot build of 2.7.5-SNAPSHOT (it builds at about 05:00 UTC)
https://repository.apache.org/content/repositories/snapshots/org/apache/jena/apache-jena/
By the way, you can execute algebra expressions directly:
DatasetGraph dsg = ...
QueryIterator qIter = Algebra.exec(op, dsg) ;
Not all algebra expressions can be turned into a query. If you are
manipulating the algebra, you can create forms OpAsQuery does not recognize.
Andy
On 26/10/12 22:24, John Liu wrote:
> I use some Jena arq apis to modify the query for adding filter in runtime.
>
> The query is
>
> PREFIX geo: <http://www.w3.org/2003/01/geo/wgs84_pos#>
> PREFIX onto: <http://dbpedia.org/ontology/>
> SELECT * WHERE {
> ?p a onto:Place .
> ?p geo:l* ?loc .
> }
>
> There is valid card in the line "?p geo:l* ?loc ."
>
> The funcations I used are:
>
> AlgebraGenerator ag = new AlgebraGenerator();
> Op op = ag.compile(query);
> op = OpFilter.filter(e, op);
> Query query2 = OpAsQuery.asQuery(op);
>
> This query causes an ARQNotImplemented exception thrown in the last function call. The exception stack trace is:
>
> com.hp.hpl.jena.sparql.ARQNotImplemented error occurred when handling the REST data service.
> Not implemented: OpPath
> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.visit(OpAsQuery.java:224)
> at com.hp.hpl.jena.sparql.algebra.op.OpPath.visit(OpPath.java:73)
> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.asElementGroup(OpAsQuery.java:97)
> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.asElement(OpAsQuery.java:88)
> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.visit(OpAsQuery.java:168)
> at com.hp.hpl.jena.sparql.algebra.op.OpSequence.visit(OpSequence.java:75)
> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.visit(OpAsQuery.java:473)
> at com.hp.hpl.jena.sparql.algebra.op.OpSlice.visit(OpSlice.java:50)
> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.asElementGroup(OpAsQuery.java:97)
> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.asElement(OpAsQuery.java:88)
> at com.hp.hpl.jena.sparql.algebra.OpAsQuery$Converter.visit(OpAsQuery.java:310)
> at com.hp.hpl.jena.sparql.algebra.op.OpFilter.visit(OpFilter.java:110)
> at com.hp.hpl.jena.sparql.algebra.OpAsQuery.asQuery(OpAsQuery.java:50)
>
> The arq library I used is jena-arq-2.9.1 and the jean is jena-core-2.7.1
>
> My question is if this is bug in the arq functions? I have tested these functions without adding the filter(the third call), but it still throws the exception.
>
> If it isa bug, how can I file a defect to it?
>
> If it is not, how can I fix my code to avoid this exception.
>
> Thanks a lot for your help.
>
> John
>