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Posted to dev@marmotta.apache.org by Sergio Fernández <se...@salzburgresearch.at> on 2014/01/07 18:08:14 UTC
Re: git commit: switched to "null" as default context (as Sesame
does)
should we discuss this change?
On Jan 7, 2014 5:23 PM, sschaffert@apache.org wrote:
>
> Updated Branches:
> refs/heads/develop 38620a9e4 -> 030a0a1df
>
>
> switched to "null" as default context (as Sesame does)
>
>
> Project: http://git-wip-us.apache.org/repos/asf/marmotta/repo
> Commit: http://git-wip-us.apache.org/repos/asf/marmotta/commit/030a0a1d
> Tree: http://git-wip-us.apache.org/repos/asf/marmotta/tree/030a0a1d
> Diff: http://git-wip-us.apache.org/repos/asf/marmotta/diff/030a0a1d
>
> Branch: refs/heads/develop
> Commit: 030a0a1df27fa22423c4dad643430269154e9ec2
> Parents: 38620a9
> Author: Sebastian Schaffert <ss...@apache.org>
> Authored: Tue Jan 7 17:23:34 2014 +0100
> Committer: Sebastian Schaffert <ss...@apache.org>
> Committed: Tue Jan 7 17:23:34 2014 +0100
>
> ----------------------------------------------------------------------
> .../kiwi/sparql/test/KiWiSparqlJoinTest.java | 12 ++++++++
> .../config/ConfigurationServiceImpl.java | 10 ++-----
> .../triplestore/ContextServiceImpl.java | 30 +++++++++++---------
> 3 files changed, 31 insertions(+), 21 deletions(-)
> ----------------------------------------------------------------------
>
>
> http://git-wip-us.apache.org/repos/asf/marmotta/blob/030a0a1d/libraries/kiwi/kiwi-sparql/src/test/java/org/apache/marmotta/kiwi/sparql/test/KiWiSparqlJoinTest.java
> ----------------------------------------------------------------------
> diff --git a/libraries/kiwi/kiwi-sparql/src/test/java/org/apache/marmotta/kiwi/sparql/test/KiWiSparqlJoinTest.java b/libraries/kiwi/kiwi-sparql/src/test/java/org/apache/marmotta/kiwi/sparql/test/KiWiSparqlJoinTest.java
> index 63f452e..b5a2028 100644
> --- a/libraries/kiwi/kiwi-sparql/src/test/java/org/apache/marmotta/kiwi/sparql/test/KiWiSparqlJoinTest.java
> +++ b/libraries/kiwi/kiwi-sparql/src/test/java/org/apache/marmotta/kiwi/sparql/test/KiWiSparqlJoinTest.java
> @@ -37,7 +37,9 @@ import org.junit.runner.Description;
> import org.junit.runner.RunWith;
> import org.openrdf.model.Statement;
> import org.openrdf.model.URI;
> +import org.openrdf.model.impl.URIImpl;
> import org.openrdf.query.*;
> +import org.openrdf.query.impl.DatasetImpl;
> import org.openrdf.repository.Repository;
> import org.openrdf.repository.RepositoryConnection;
> import org.openrdf.repository.RepositoryException;
> @@ -381,6 +383,16 @@ public class KiWiSparqlJoinTest {
> con1.begin();
>
> Update query1 = con1.prepareUpdate(QueryLanguage.SPARQL, queryString);
> + // workaround for a Sesame bug: we explicitly set the context for the query in the dataset
> +
> + URI context = new URIImpl("http://localhost/mycontext");
> + DatasetImpl ds = new DatasetImpl();
> + //ds.addDefaultGraph(context);
> + //ds.addNamedGraph(context);
> + //ds.addDefaultRemoveGraph(context);
> + ds.setDefaultInsertGraph(context);
> + query1.setDataset(ds);
> +
> query1.execute();
>
> con1.commit();
>
> http://git-wip-us.apache.org/repos/asf/marmotta/blob/030a0a1d/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/config/ConfigurationServiceImpl.java
> ----------------------------------------------------------------------
> diff --git a/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/config/ConfigurationServiceImpl.java b/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/config/ConfigurationServiceImpl.java
> index 752fe74..df13c5e 100644
> --- a/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/config/ConfigurationServiceImpl.java
> +++ b/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/config/ConfigurationServiceImpl.java
> @@ -19,12 +19,7 @@ package org.apache.marmotta.platform.core.services.config;
>
> import com.google.common.base.Preconditions;
> import com.google.common.collect.Lists;
> -import org.apache.commons.configuration.AbstractConfiguration;
> -import org.apache.commons.configuration.CompositeConfiguration;
> -import org.apache.commons.configuration.Configuration;
> -import org.apache.commons.configuration.ConfigurationException;
> -import org.apache.commons.configuration.MapConfiguration;
> -import org.apache.commons.configuration.PropertiesConfiguration;
> +import org.apache.commons.configuration.*;
> import org.apache.commons.lang3.ObjectUtils;
> import org.apache.commons.lang3.StringUtils;
> import org.apache.marmotta.platform.core.api.config.ConfigurationService;
> @@ -1260,7 +1255,8 @@ public class ConfigurationServiceImpl implements ConfigurationService {
> */
> @Override
> public String getDefaultContext() {
> - return getBaseUri() + CONTEXT_PATH + "/" + CONTEXT_DEFAULT;
> + //return getBaseUri() + CONTEXT_PATH + "/" + CONTEXT_DEFAULT;
> + return null;
> }
>
> /**
>
> http://git-wip-us.apache.org/repos/asf/marmotta/blob/030a0a1d/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/triplestore/ContextServiceImpl.java
> ----------------------------------------------------------------------
> diff --git a/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/triplestore/ContextServiceImpl.java b/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/triplestore/ContextServiceImpl.java
> index 63c958e..b49c556 100644
> --- a/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/triplestore/ContextServiceImpl.java
> +++ b/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/triplestore/ContextServiceImpl.java
> @@ -17,20 +17,6 @@
> */
> package org.apache.marmotta.platform.core.services.triplestore;
>
> -import static org.apache.marmotta.commons.sesame.repository.ExceptionUtils.handleRepositoryException;
> -
> -import java.io.InputStream;
> -import java.net.URISyntaxException;
> -import java.util.ArrayList;
> -import java.util.List;
> -import java.util.Set;
> -
> -import javax.enterprise.context.ApplicationScoped;
> -import javax.enterprise.context.RequestScoped;
> -import javax.enterprise.inject.Produces;
> -import javax.inject.Inject;
> -import javax.inject.Named;
> -
> import org.apache.commons.lang3.StringUtils;
> import org.apache.marmotta.commons.http.UriUtil;
> import org.apache.marmotta.commons.sesame.repository.ResourceUtils;
> @@ -54,6 +40,19 @@ import org.openrdf.repository.RepositoryException;
> import org.openrdf.repository.RepositoryResult;
> import org.slf4j.Logger;
>
> +import javax.enterprise.context.ApplicationScoped;
> +import javax.enterprise.context.RequestScoped;
> +import javax.enterprise.inject.Produces;
> +import javax.inject.Inject;
> +import javax.inject.Named;
> +import java.io.InputStream;
> +import java.net.URISyntaxException;
> +import java.util.ArrayList;
> +import java.util.List;
> +import java.util.Set;
> +
> +import static org.apache.marmotta.commons.sesame.repository.ExceptionUtils.handleRepositoryException;
> +
> /**
> * The context (named graphs in Apache Marmotta, formerly "knowledge space" in KiWi) service offers convenience
> * functions for working with Apache Marmotta Contexts. Low level manipulation of contexts is offered by
> @@ -177,6 +176,9 @@ public class ContextServiceImpl implements ContextService {
>
> @Override
> public URI createContext(String uri, String label) throws URISyntaxException {
> + if(uri == null) {
> + return null;
> + }
> if (!UriUtil.validate(uri)) {
> uri = configurationService.getBaseContext() + uri;
> if (!UriUtil.validate(uri)) {
>
Re: git commit: switched to "null" as default context (as Sesame does)
Posted by Sebastian Schaffert <se...@gmail.com>.
Hi Peter,
thanks for the feedback, comments below. :)
2014/1/7 Peter Ansell <an...@gmail.com>
> Hi All,
>
> It is a difficult issue, and has been discussed in a few places in
> relation to SPARQL, but not really in relation to the Statement or
> Repository/Sail APIs:
>
> http://www.openrdf.org/issues/browse/SES-848
> http://www.openrdf.org/issues/browse/SES-850
> https://openrdf.atlassian.net/browse/SES-850
>
> From experience on the sesame mailing list, it seems that most users
> have found it fairly simple to either use "null" for all statements,
> or avoid using the default context for any statements. I don't use the
> null context in my permanent repository instances for my projects.
> There are some users who specifically use the default context as a
> management graph referencing the other named graphs, but personally I
> prefer to use well-known URI graph names for that purpose as it is
> clearer what is happening in SPARQL queries and when using the
> Repository API.
>
I also personally prefer having an explicit default graph. However, the
null-context is unfortunately used implicitly or explicitly in many places
in Sesame, especially in SPARQL. The concrete case where I was having
trouble was an DELETE/INSERT/WHERE update query, e.g.
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
PREFIX dc: <http://purl.org/dc/elements/1.1/>
PREFIX mm: <http://marmotta.apache.org/vocabulary/sparql-functions#>
DELETE { ?s foaf:name ?o . }
INSERT { ?s foaf:name "Johannes Meier" }
WHERE { ?s foaf:name ?o . FILTER(?s = <
http://localhost:8080/LMF/resource/hans_meier>) }
In this case, the default insert graph set in the Dataset of the update
query is ignored in case the value factory already assigns a non-null
context to the ground statement instatiated from the insert statement
pattern and variable bindings. The reason is in
SailUpdateExecutor.insertBoundTriples, line 583 (if-statement). In this
line it checks if the context of the insert statement is null and only in
this case uses the default insert context from the dataset. Which makes
sense, in a way, because it is not an "override insert context" but a
"default insert context". Unfortunately, it also hard codes the semantics
of "null as default".
Funny thing is that it works for other kinds of SPARQL updates, e.g. INSERT
DATA. Unfortunately I don't know which other parts could be affected, so I
think it is safer to use the default Sesame semantics for now.
Greetings,
Sebastian
Re: git commit: switched to "null" as default context (as Sesame does)
Posted by Peter Ansell <an...@gmail.com>.
Hi All,
It is a difficult issue, and has been discussed in a few places in
relation to SPARQL, but not really in relation to the Statement or
Repository/Sail APIs:
http://www.openrdf.org/issues/browse/SES-848
http://www.openrdf.org/issues/browse/SES-850
https://openrdf.atlassian.net/browse/SES-850
>From experience on the sesame mailing list, it seems that most users
have found it fairly simple to either use "null" for all statements,
or avoid using the default context for any statements. I don't use the
null context in my permanent repository instances for my projects.
There are some users who specifically use the default context as a
management graph referencing the other named graphs, but personally I
prefer to use well-known URI graph names for that purpose as it is
clearer what is happening in SPARQL queries and when using the
Repository API.
Cheers,
Peter
On 8 January 2014 05:45, Sebastian Schaffert
<se...@gmail.com> wrote:
> Forward to mailing list for everyone to follow :-)
> Am 07.01.2014 19:43 schrieb "Sebastian Schaffert" <ss...@apache.org>:
>
>> The change is necessary because some Sesame functionality depends on the
>> default context being null. In this case it was a contextual SPARQL update
>> which went wrong because of the default not being null.
>>
>> The triple store supported the null context already for quite some time
>> because otherwise the Sesame test suite would not work. The current change
>> only affects the platform, which in my tests worked just fine (only thing
>> is the default context no longer appears in the context manager).
>>
>> To keep backwards compatibility the default context is now configurable -
>> when contexts.default is empty null is used, the default is the old URI
>> value.
>>
>> In the long run we should either use the Sesame way or Sesame needs some
>> extensions to support configurable defaults. Other backends than KiWi don't
>> support this anyways.
>>
>> Greetings
>>
>> Sebastian
>> Am 07.01.2014 18:09 schrieb "Sergio Fernández" <
>> sergio.fernandez@salzburgresearch.at>:
>>
>>> should we discuss this change?
>>>
>>> On Jan 7, 2014 5:23 PM, sschaffert@apache.org wrote:
>>> >
>>> > Updated Branches:
>>> > refs/heads/develop 38620a9e4 -> 030a0a1df
>>> >
>>> >
>>> > switched to "null" as default context (as Sesame does)
>>> >
>>> >
>>> > Project: http://git-wip-us.apache.org/repos/asf/marmotta/repo
>>> > Commit: http://git-wip-us.apache.org/repos/asf/marmotta/commit/030a0a1d
>>> > Tree: http://git-wip-us.apache.org/repos/asf/marmotta/tree/030a0a1d
>>> > Diff: http://git-wip-us.apache.org/repos/asf/marmotta/diff/030a0a1d
>>> >
>>> > Branch: refs/heads/develop
>>> > Commit: 030a0a1df27fa22423c4dad643430269154e9ec2
>>> > Parents: 38620a9
>>> > Author: Sebastian Schaffert <ss...@apache.org>
>>> > Authored: Tue Jan 7 17:23:34 2014 +0100
>>> > Committer: Sebastian Schaffert <ss...@apache.org>
>>> > Committed: Tue Jan 7 17:23:34 2014 +0100
>>> >
>>> > ----------------------------------------------------------------------
>>> > .../kiwi/sparql/test/KiWiSparqlJoinTest.java | 12 ++++++++
>>> > .../config/ConfigurationServiceImpl.java | 10 ++-----
>>> > .../triplestore/ContextServiceImpl.java | 30
>>> +++++++++++---------
>>> > 3 files changed, 31 insertions(+), 21 deletions(-)
>>> > ----------------------------------------------------------------------
>>> >
>>> >
>>> >
>>> http://git-wip-us.apache.org/repos/asf/marmotta/blob/030a0a1d/libraries/kiwi/kiwi-sparql/src/test/java/org/apache/marmotta/kiwi/sparql/test/KiWiSparqlJoinTest.java
>>> > ----------------------------------------------------------------------
>>> > diff --git
>>> a/libraries/kiwi/kiwi-sparql/src/test/java/org/apache/marmotta/kiwi/sparql/test/KiWiSparqlJoinTest.java
>>> b/libraries/kiwi/kiwi-sparql/src/test/java/org/apache/marmotta/kiwi/sparql/test/KiWiSparqlJoinTest.java
>>> > index 63f452e..b5a2028 100644
>>> > ---
>>> a/libraries/kiwi/kiwi-sparql/src/test/java/org/apache/marmotta/kiwi/sparql/test/KiWiSparqlJoinTest.java
>>> > +++
>>> b/libraries/kiwi/kiwi-sparql/src/test/java/org/apache/marmotta/kiwi/sparql/test/KiWiSparqlJoinTest.java
>>> > @@ -37,7 +37,9 @@ import org.junit.runner.Description;
>>> > import org.junit.runner.RunWith;
>>> > import org.openrdf.model.Statement;
>>> > import org.openrdf.model.URI;
>>> > +import org.openrdf.model.impl.URIImpl;
>>> > import org.openrdf.query.*;
>>> > +import org.openrdf.query.impl.DatasetImpl;
>>> > import org.openrdf.repository.Repository;
>>> > import org.openrdf.repository.RepositoryConnection;
>>> > import org.openrdf.repository.RepositoryException;
>>> > @@ -381,6 +383,16 @@ public class KiWiSparqlJoinTest {
>>> > con1.begin();
>>> >
>>> > Update query1 = con1.prepareUpdate(QueryLanguage.SPARQL,
>>> queryString);
>>> > + // workaround for a Sesame bug: we explicitly set the
>>> context for the query in the dataset
>>> > +
>>> > + URI context = new URIImpl("http://localhost/mycontext");
>>> > + DatasetImpl ds = new DatasetImpl();
>>> > + //ds.addDefaultGraph(context);
>>> > + //ds.addNamedGraph(context);
>>> > + //ds.addDefaultRemoveGraph(context);
>>> > + ds.setDefaultInsertGraph(context);
>>> > + query1.setDataset(ds);
>>> > +
>>> > query1.execute();
>>> >
>>> > con1.commit();
>>> >
>>> >
>>> http://git-wip-us.apache.org/repos/asf/marmotta/blob/030a0a1d/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/config/ConfigurationServiceImpl.java
>>> > ----------------------------------------------------------------------
>>> > diff --git
>>> a/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/config/ConfigurationServiceImpl.java
>>> b/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/config/ConfigurationServiceImpl.java
>>> > index 752fe74..df13c5e 100644
>>> > ---
>>> a/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/config/ConfigurationServiceImpl.java
>>> > +++
>>> b/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/config/ConfigurationServiceImpl.java
>>> > @@ -19,12 +19,7 @@ package
>>> org.apache.marmotta.platform.core.services.config;
>>> >
>>> > import com.google.common.base.Preconditions;
>>> > import com.google.common.collect.Lists;
>>> > -import org.apache.commons.configuration.AbstractConfiguration;
>>> > -import org.apache.commons.configuration.CompositeConfiguration;
>>> > -import org.apache.commons.configuration.Configuration;
>>> > -import org.apache.commons.configuration.ConfigurationException;
>>> > -import org.apache.commons.configuration.MapConfiguration;
>>> > -import org.apache.commons.configuration.PropertiesConfiguration;
>>> > +import org.apache.commons.configuration.*;
>>> > import org.apache.commons.lang3.ObjectUtils;
>>> > import org.apache.commons.lang3.StringUtils;
>>> > import
>>> org.apache.marmotta.platform.core.api.config.ConfigurationService;
>>> > @@ -1260,7 +1255,8 @@ public class ConfigurationServiceImpl implements
>>> ConfigurationService {
>>> > */
>>> > @Override
>>> > public String getDefaultContext() {
>>> > - return getBaseUri() + CONTEXT_PATH + "/" + CONTEXT_DEFAULT;
>>> > + //return getBaseUri() + CONTEXT_PATH + "/" + CONTEXT_DEFAULT;
>>> > + return null;
>>> > }
>>> >
>>> > /**
>>> >
>>> >
>>> http://git-wip-us.apache.org/repos/asf/marmotta/blob/030a0a1d/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/triplestore/ContextServiceImpl.java
>>> > ----------------------------------------------------------------------
>>> > diff --git
>>> a/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/triplestore/ContextServiceImpl.java
>>> b/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/triplestore/ContextServiceImpl.java
>>> > index 63c958e..b49c556 100644
>>> > ---
>>> a/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/triplestore/ContextServiceImpl.java
>>> > +++
>>> b/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/triplestore/ContextServiceImpl.java
>>> > @@ -17,20 +17,6 @@
>>> > */
>>> > package org.apache.marmotta.platform.core.services.triplestore;
>>> >
>>> > -import static
>>> org.apache.marmotta.commons.sesame.repository.ExceptionUtils.handleRepositoryException;
>>> > -
>>> > -import java.io.InputStream;
>>> > -import java.net.URISyntaxException;
>>> > -import java.util.ArrayList;
>>> > -import java.util.List;
>>> > -import java.util.Set;
>>> > -
>>> > -import javax.enterprise.context.ApplicationScoped;
>>> > -import javax.enterprise.context.RequestScoped;
>>> > -import javax.enterprise.inject.Produces;
>>> > -import javax.inject.Inject;
>>> > -import javax.inject.Named;
>>> > -
>>> > import org.apache.commons.lang3.StringUtils;
>>> > import org.apache.marmotta.commons.http.UriUtil;
>>> > import org.apache.marmotta.commons.sesame.repository.ResourceUtils;
>>> > @@ -54,6 +40,19 @@ import org.openrdf.repository.RepositoryException;
>>> > import org.openrdf.repository.RepositoryResult;
>>> > import org.slf4j.Logger;
>>> >
>>> > +import javax.enterprise.context.ApplicationScoped;
>>> > +import javax.enterprise.context.RequestScoped;
>>> > +import javax.enterprise.inject.Produces;
>>> > +import javax.inject.Inject;
>>> > +import javax.inject.Named;
>>> > +import java.io.InputStream;
>>> > +import java.net.URISyntaxException;
>>> > +import java.util.ArrayList;
>>> > +import java.util.List;
>>> > +import java.util.Set;
>>> > +
>>> > +import static
>>> org.apache.marmotta.commons.sesame.repository.ExceptionUtils.handleRepositoryException;
>>> > +
>>> > /**
>>> > * The context (named graphs in Apache Marmotta, formerly "knowledge
>>> space" in KiWi) service offers convenience
>>> > * functions for working with Apache Marmotta Contexts. Low level
>>> manipulation of contexts is offered by
>>> > @@ -177,6 +176,9 @@ public class ContextServiceImpl implements
>>> ContextService {
>>> >
>>> > @Override
>>> > public URI createContext(String uri, String label) throws
>>> URISyntaxException {
>>> > + if(uri == null) {
>>> > + return null;
>>> > + }
>>> > if (!UriUtil.validate(uri)) {
>>> > uri = configurationService.getBaseContext() + uri;
>>> > if (!UriUtil.validate(uri)) {
>>> >
>>>
>>
Re: git commit: switched to "null" as default context (as Sesame does)
Posted by Sebastian Schaffert <se...@gmail.com>.
Forward to mailing list for everyone to follow :-)
Am 07.01.2014 19:43 schrieb "Sebastian Schaffert" <ss...@apache.org>:
> The change is necessary because some Sesame functionality depends on the
> default context being null. In this case it was a contextual SPARQL update
> which went wrong because of the default not being null.
>
> The triple store supported the null context already for quite some time
> because otherwise the Sesame test suite would not work. The current change
> only affects the platform, which in my tests worked just fine (only thing
> is the default context no longer appears in the context manager).
>
> To keep backwards compatibility the default context is now configurable -
> when contexts.default is empty null is used, the default is the old URI
> value.
>
> In the long run we should either use the Sesame way or Sesame needs some
> extensions to support configurable defaults. Other backends than KiWi don't
> support this anyways.
>
> Greetings
>
> Sebastian
> Am 07.01.2014 18:09 schrieb "Sergio Fernández" <
> sergio.fernandez@salzburgresearch.at>:
>
>> should we discuss this change?
>>
>> On Jan 7, 2014 5:23 PM, sschaffert@apache.org wrote:
>> >
>> > Updated Branches:
>> > refs/heads/develop 38620a9e4 -> 030a0a1df
>> >
>> >
>> > switched to "null" as default context (as Sesame does)
>> >
>> >
>> > Project: http://git-wip-us.apache.org/repos/asf/marmotta/repo
>> > Commit: http://git-wip-us.apache.org/repos/asf/marmotta/commit/030a0a1d
>> > Tree: http://git-wip-us.apache.org/repos/asf/marmotta/tree/030a0a1d
>> > Diff: http://git-wip-us.apache.org/repos/asf/marmotta/diff/030a0a1d
>> >
>> > Branch: refs/heads/develop
>> > Commit: 030a0a1df27fa22423c4dad643430269154e9ec2
>> > Parents: 38620a9
>> > Author: Sebastian Schaffert <ss...@apache.org>
>> > Authored: Tue Jan 7 17:23:34 2014 +0100
>> > Committer: Sebastian Schaffert <ss...@apache.org>
>> > Committed: Tue Jan 7 17:23:34 2014 +0100
>> >
>> > ----------------------------------------------------------------------
>> > .../kiwi/sparql/test/KiWiSparqlJoinTest.java | 12 ++++++++
>> > .../config/ConfigurationServiceImpl.java | 10 ++-----
>> > .../triplestore/ContextServiceImpl.java | 30
>> +++++++++++---------
>> > 3 files changed, 31 insertions(+), 21 deletions(-)
>> > ----------------------------------------------------------------------
>> >
>> >
>> >
>> http://git-wip-us.apache.org/repos/asf/marmotta/blob/030a0a1d/libraries/kiwi/kiwi-sparql/src/test/java/org/apache/marmotta/kiwi/sparql/test/KiWiSparqlJoinTest.java
>> > ----------------------------------------------------------------------
>> > diff --git
>> a/libraries/kiwi/kiwi-sparql/src/test/java/org/apache/marmotta/kiwi/sparql/test/KiWiSparqlJoinTest.java
>> b/libraries/kiwi/kiwi-sparql/src/test/java/org/apache/marmotta/kiwi/sparql/test/KiWiSparqlJoinTest.java
>> > index 63f452e..b5a2028 100644
>> > ---
>> a/libraries/kiwi/kiwi-sparql/src/test/java/org/apache/marmotta/kiwi/sparql/test/KiWiSparqlJoinTest.java
>> > +++
>> b/libraries/kiwi/kiwi-sparql/src/test/java/org/apache/marmotta/kiwi/sparql/test/KiWiSparqlJoinTest.java
>> > @@ -37,7 +37,9 @@ import org.junit.runner.Description;
>> > import org.junit.runner.RunWith;
>> > import org.openrdf.model.Statement;
>> > import org.openrdf.model.URI;
>> > +import org.openrdf.model.impl.URIImpl;
>> > import org.openrdf.query.*;
>> > +import org.openrdf.query.impl.DatasetImpl;
>> > import org.openrdf.repository.Repository;
>> > import org.openrdf.repository.RepositoryConnection;
>> > import org.openrdf.repository.RepositoryException;
>> > @@ -381,6 +383,16 @@ public class KiWiSparqlJoinTest {
>> > con1.begin();
>> >
>> > Update query1 = con1.prepareUpdate(QueryLanguage.SPARQL,
>> queryString);
>> > + // workaround for a Sesame bug: we explicitly set the
>> context for the query in the dataset
>> > +
>> > + URI context = new URIImpl("http://localhost/mycontext");
>> > + DatasetImpl ds = new DatasetImpl();
>> > + //ds.addDefaultGraph(context);
>> > + //ds.addNamedGraph(context);
>> > + //ds.addDefaultRemoveGraph(context);
>> > + ds.setDefaultInsertGraph(context);
>> > + query1.setDataset(ds);
>> > +
>> > query1.execute();
>> >
>> > con1.commit();
>> >
>> >
>> http://git-wip-us.apache.org/repos/asf/marmotta/blob/030a0a1d/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/config/ConfigurationServiceImpl.java
>> > ----------------------------------------------------------------------
>> > diff --git
>> a/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/config/ConfigurationServiceImpl.java
>> b/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/config/ConfigurationServiceImpl.java
>> > index 752fe74..df13c5e 100644
>> > ---
>> a/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/config/ConfigurationServiceImpl.java
>> > +++
>> b/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/config/ConfigurationServiceImpl.java
>> > @@ -19,12 +19,7 @@ package
>> org.apache.marmotta.platform.core.services.config;
>> >
>> > import com.google.common.base.Preconditions;
>> > import com.google.common.collect.Lists;
>> > -import org.apache.commons.configuration.AbstractConfiguration;
>> > -import org.apache.commons.configuration.CompositeConfiguration;
>> > -import org.apache.commons.configuration.Configuration;
>> > -import org.apache.commons.configuration.ConfigurationException;
>> > -import org.apache.commons.configuration.MapConfiguration;
>> > -import org.apache.commons.configuration.PropertiesConfiguration;
>> > +import org.apache.commons.configuration.*;
>> > import org.apache.commons.lang3.ObjectUtils;
>> > import org.apache.commons.lang3.StringUtils;
>> > import
>> org.apache.marmotta.platform.core.api.config.ConfigurationService;
>> > @@ -1260,7 +1255,8 @@ public class ConfigurationServiceImpl implements
>> ConfigurationService {
>> > */
>> > @Override
>> > public String getDefaultContext() {
>> > - return getBaseUri() + CONTEXT_PATH + "/" + CONTEXT_DEFAULT;
>> > + //return getBaseUri() + CONTEXT_PATH + "/" + CONTEXT_DEFAULT;
>> > + return null;
>> > }
>> >
>> > /**
>> >
>> >
>> http://git-wip-us.apache.org/repos/asf/marmotta/blob/030a0a1d/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/triplestore/ContextServiceImpl.java
>> > ----------------------------------------------------------------------
>> > diff --git
>> a/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/triplestore/ContextServiceImpl.java
>> b/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/triplestore/ContextServiceImpl.java
>> > index 63c958e..b49c556 100644
>> > ---
>> a/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/triplestore/ContextServiceImpl.java
>> > +++
>> b/platform/marmotta-core/src/main/java/org/apache/marmotta/platform/core/services/triplestore/ContextServiceImpl.java
>> > @@ -17,20 +17,6 @@
>> > */
>> > package org.apache.marmotta.platform.core.services.triplestore;
>> >
>> > -import static
>> org.apache.marmotta.commons.sesame.repository.ExceptionUtils.handleRepositoryException;
>> > -
>> > -import java.io.InputStream;
>> > -import java.net.URISyntaxException;
>> > -import java.util.ArrayList;
>> > -import java.util.List;
>> > -import java.util.Set;
>> > -
>> > -import javax.enterprise.context.ApplicationScoped;
>> > -import javax.enterprise.context.RequestScoped;
>> > -import javax.enterprise.inject.Produces;
>> > -import javax.inject.Inject;
>> > -import javax.inject.Named;
>> > -
>> > import org.apache.commons.lang3.StringUtils;
>> > import org.apache.marmotta.commons.http.UriUtil;
>> > import org.apache.marmotta.commons.sesame.repository.ResourceUtils;
>> > @@ -54,6 +40,19 @@ import org.openrdf.repository.RepositoryException;
>> > import org.openrdf.repository.RepositoryResult;
>> > import org.slf4j.Logger;
>> >
>> > +import javax.enterprise.context.ApplicationScoped;
>> > +import javax.enterprise.context.RequestScoped;
>> > +import javax.enterprise.inject.Produces;
>> > +import javax.inject.Inject;
>> > +import javax.inject.Named;
>> > +import java.io.InputStream;
>> > +import java.net.URISyntaxException;
>> > +import java.util.ArrayList;
>> > +import java.util.List;
>> > +import java.util.Set;
>> > +
>> > +import static
>> org.apache.marmotta.commons.sesame.repository.ExceptionUtils.handleRepositoryException;
>> > +
>> > /**
>> > * The context (named graphs in Apache Marmotta, formerly "knowledge
>> space" in KiWi) service offers convenience
>> > * functions for working with Apache Marmotta Contexts. Low level
>> manipulation of contexts is offered by
>> > @@ -177,6 +176,9 @@ public class ContextServiceImpl implements
>> ContextService {
>> >
>> > @Override
>> > public URI createContext(String uri, String label) throws
>> URISyntaxException {
>> > + if(uri == null) {
>> > + return null;
>> > + }
>> > if (!UriUtil.validate(uri)) {
>> > uri = configurationService.getBaseContext() + uri;
>> > if (!UriUtil.validate(uri)) {
>> >
>>
>