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Posted to users@jena.apache.org by Chris Dollin <ch...@epimorphics.com> on 2017/11/17 16:14:42 UTC
problem with query builder
Hi,
I was experimenting with the query builder and hit a problem
when I was attempting to construct an Expr. This example:
package com.epimorphics.scratch;
import org.apache.jena.arq.querybuilder.ConstructBuilder;
import org.apache.jena.sparql.expr.E_GreaterThan;
import org.apache.jena.sparql.expr.Expr;
import org.apache.jena.sparql.expr.ExprVar;
import org.apache.jena.sparql.expr.nodevalue.NodeValueInteger;
import org.junit.Test;
public class Example {
@Test public void tryBuilding() {
ConstructBuilder cb = new ConstructBuilder();
Expr x = new NodeValueInteger(1);
Expr y = new ExprVar("y");
Expr e = new E_GreaterThan(x, y);
cb.addFilter(e);
System.err.println(cb.buildString());
}
}
when run fails with a null pointer exception:
java.lang.NullPointerException
at org.apache.jena.arq.querybuilder.rewriters.
AbstractRewriter.changeNode(AbstractRewriter.java:126)
at org.apache.jena.arq.querybuilder.rewriters.NodeValueRewriter.visit(
NodeValueRewriter.java:64)
at org.apache.jena.sparql.expr.nodevalue.NodeValueInteger.
visit(NodeValueInteger.java:78)
at org.apache.jena.arq.querybuilder.rewriters.ExprRewriter.visit(
ExprRewriter.java:127)
at org.apache.jena.sparql.expr.NodeValue.visit(NodeValue.java:1205)
at org.apache.jena.arq.querybuilder.rewriters.ExprRewriter.visit(
ExprRewriter.java:65)
at org.apache.jena.sparql.expr.ExprFunction2.visit(
ExprFunction2.java:109)
at org.apache.jena.arq.querybuilder.rewriters.ElementRewriter.visit(
ElementRewriter.java:70)
at org.apache.jena.sparql.syntax.ElementFilter.visit(
ElementFilter.java:35)
at org.apache.jena.arq.querybuilder.rewriters.ElementRewriter.visit(
ElementRewriter.java:141)
at org.apache.jena.sparql.syntax.ElementGroup.visit(
ElementGroup.java:120)
at org.apache.jena.arq.querybuilder.handlers.WhereHandler.addAll(
WhereHandler.java:81)
at org.apache.jena.arq.querybuilder.handlers.HandlerBlock.addAll(
HandlerBlock.java:218)
at org.apache.jena.arq.querybuilder.handlers.HandlerBlock.addAll(
HandlerBlock.java:245)
at org.apache.jena.arq.querybuilder.AbstractQueryBuilder.build(
AbstractQueryBuilder.java:555)
at org.apache.jena.arq.querybuilder.AbstractQueryBuilder.buildString(
AbstractQueryBuilder.java:522)
at com.epimorphics.scratch.Example.tryBuilding(Example.java:20)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(
NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(
DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(
FrameworkMethod.java:47)
at org.junit.internal.runners.model.ReflectiveCallable.run(
ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(
FrameworkMethod.java:44)
at org.junit.internal.runners.statements.InvokeMethod.
evaluate(InvokeMethod.java:17)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(
BlockJUnit4ClassRunner.java:70)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(
BlockJUnit4ClassRunner.java:50)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
at org.junit.runner.JUnitCore.run(JUnitCore.java:160)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(
JUnit4IdeaTestRunner.java:68)
at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.
startRunnerWithArgs(IdeaTestRunner.java:47)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(
JUnitStarter.java:242)
at com.intellij.rt.execution.junit.JUnitStarter.main(
JUnitStarter.java:70)
Replacing the addFilter line with
cb.addFilter("1 > ?y");
does not fail, terminating with the expected print-out
of a construct query
CONSTRUCT
{
}
WHERE
{ FILTER ( 1 > ?y )}
I tried poking around with the debugger but couldn't see anyhting
obvious. However, /sometimes/ stepping through the code
results in it working and sometimes not, presumably depending
on exactly when I give up through-stepping.
Am I doing anything obviously wrong (like misunderstanding
how to use the Expr functionality) or should I file a JIRA?
This is Jena 3.4.0.
Chris
--
"What I don't understand is this ..." Trevor Chaplin, /The Beiderbeck
Affair/
Epimorphics Ltd, http://www.epimorphics.com
Registered address: Court Lodge, 105 High Street, Portishead, Bristol BS20
6PT
Epimorphics Ltd. is a limited company registered in England (number 7016688)
Re: problem with query builder
Posted by Chris Dollin <ch...@epimorphics.com>.
Thanks for the diagnosis, workaround, and fix, Claude.
Chris
On 18 November 2017 at 18:27, Claude Warren <cl...@xenei.com> wrote:
> Fix coming shortly but the work around is...
>
> change:
>
> Expr x = new NodeValueInteger(1)
>
> to:
>
> NodeValue nv = new NodeValueInteger(1)
> nv.asNode()
> Expr x = nv;
>
> Claude
>
> On Sat, Nov 18, 2017 at 3:48 PM, Claude Warren <cl...@xenei.com> wrote:
>
> > Well done Andy. Right on the money, exactly what I discovered.
> >
> > On Sat, Nov 18, 2017 at 3:39 PM, Andy Seaborne <an...@apache.org> wrote:
> >
> >> c.f. NodeValue.getNode and NodeValue.asNode
> >>
> >> Presumably something calls getNode when it wanted asNode.
> >>
> >>
> >> On 18/11/17 15:36, Claude Warren wrote:
> >>
> >>> This is a bug. The problem is that new NodeValueInteger(1);
> >>> does not set the Node value that the rewriter is trying to rewrite and
> >>> thus
> >>> the null pointer exception.
> >>>
> >>> I will get a fix out shortly.
> >>>
> >>> Claude
> >>>
> >>> On Fri, Nov 17, 2017 at 4:14 PM, Chris Dollin <
> >>> chris.dollin@epimorphics.com>
> >>> wrote:
> >>>
> >>> Hi,
> >>>>
> >>>> I was experimenting with the query builder and hit a problem
> >>>> when I was attempting to construct an Expr. This example:
> >>>>
> >>>> package com.epimorphics.scratch;
> >>>>
> >>>> import org.apache.jena.arq.querybuilder.ConstructBuilder;
> >>>> import org.apache.jena.sparql.expr.E_GreaterThan;
> >>>> import org.apache.jena.sparql.expr.Expr;
> >>>> import org.apache.jena.sparql.expr.ExprVar;
> >>>> import org.apache.jena.sparql.expr.nodevalue.NodeValueInteger;
> >>>> import org.junit.Test;
> >>>>
> >>>> public class Example {
> >>>>
> >>>> @Test public void tryBuilding() {
> >>>> ConstructBuilder cb = new ConstructBuilder();
> >>>>
> >>>> Expr x = new NodeValueInteger(1);
> >>>> Expr y = new ExprVar("y");
> >>>> Expr e = new E_GreaterThan(x, y);
> >>>> cb.addFilter(e);
> >>>> System.err.println(cb.buildString());
> >>>> }
> >>>> }
> >>>>
> >>>> when run fails with a null pointer exception:
> >>>>
> >>>> java.lang.NullPointerException
> >>>> at org.apache.jena.arq.querybuilder.rewriters.
> >>>> AbstractRewriter.changeNode(AbstractRewriter.java:126)
> >>>> at org.apache.jena.arq.querybuilder.rewriters.NodeValueRewriter
> >>>> .visit(
> >>>> NodeValueRewriter.java:64)
> >>>> at org.apache.jena.sparql.expr.nodevalue.NodeValueInteger.
> >>>> visit(NodeValueInteger.java:78)
> >>>> at org.apache.jena.arq.querybuilder.rewriters.
> ExprRewriter.visit(
> >>>> ExprRewriter.java:127)
> >>>> at org.apache.jena.sparql.expr.NodeValue.visit(NodeValue.java:1
> >>>> 205)
> >>>> at org.apache.jena.arq.querybuilder.rewriters.
> ExprRewriter.visit(
> >>>> ExprRewriter.java:65)
> >>>> at org.apache.jena.sparql.expr.ExprFunction2.visit(
> >>>> ExprFunction2.java:109)
> >>>> at org.apache.jena.arq.querybuilder.rewriters.ElementRewriter.v
> >>>> isit(
> >>>> ElementRewriter.java:70)
> >>>> at org.apache.jena.sparql.syntax.ElementFilter.visit(
> >>>> ElementFilter.java:35)
> >>>> at org.apache.jena.arq.querybuilder.rewriters.ElementRewriter.v
> >>>> isit(
> >>>> ElementRewriter.java:141)
> >>>> at org.apache.jena.sparql.syntax.ElementGroup.visit(
> >>>> ElementGroup.java:120)
> >>>> at org.apache.jena.arq.querybuilder.handlers.
> WhereHandler.addAll(
> >>>> WhereHandler.java:81)
> >>>> at org.apache.jena.arq.querybuilder.handlers.
> HandlerBlock.addAll(
> >>>> HandlerBlock.java:218)
> >>>> at org.apache.jena.arq.querybuilder.handlers.
> HandlerBlock.addAll(
> >>>> HandlerBlock.java:245)
> >>>> at org.apache.jena.arq.querybuilder.AbstractQueryBuilder.build(
> >>>> AbstractQueryBuilder.java:555)
> >>>> at org.apache.jena.arq.querybuilder.AbstractQueryBuilder.buildS
> >>>> tring(
> >>>> AbstractQueryBuilder.java:522)
> >>>> at com.epimorphics.scratch.Example.tryBuilding(Example.java:20)
> >>>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> >>>> at sun.reflect.NativeMethodAccessorImpl.invoke(
> >>>> NativeMethodAccessorImpl.java:62)
> >>>> at sun.reflect.DelegatingMethodAccessorImpl.invoke(
> >>>> DelegatingMethodAccessorImpl.java:43)
> >>>> at java.lang.reflect.Method.invoke(Method.java:498)
> >>>> at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(
> >>>> FrameworkMethod.java:47)
> >>>> at org.junit.internal.runners.model.ReflectiveCallable.run(
> >>>> ReflectiveCallable.java:12)
> >>>> at org.junit.runners.model.FrameworkMethod.invokeExplosively(
> >>>> FrameworkMethod.java:44)
> >>>> at org.junit.internal.runners.statements.InvokeMethod.
> >>>> evaluate(InvokeMethod.java:17)
> >>>> at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
> >>>> at org.junit.runners.BlockJUnit4ClassRunner.runChild(
> >>>> BlockJUnit4ClassRunner.java:70)
> >>>> at org.junit.runners.BlockJUnit4ClassRunner.runChild(
> >>>> BlockJUnit4ClassRunner.java:50)
> >>>> at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
> >>>> at org.junit.runners.ParentRunner$1.schedule(
> ParentRunner.java:63)
> >>>> at org.junit.runners.ParentRunner.runChildren(ParentRunner.java
> >>>> :236)
> >>>> at org.junit.runners.ParentRunner.access$000(
> ParentRunner.java:53)
> >>>> at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:
> >>>> 229)
> >>>> at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
> >>>> at org.junit.runner.JUnitCore.run(JUnitCore.java:160)
> >>>> at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(
> >>>> JUnit4IdeaTestRunner.java:68)
> >>>> at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.
> >>>> startRunnerWithArgs(IdeaTestRunner.java:47)
> >>>> at com.intellij.rt.execution.junit.JUnitStarter.
> >>>> prepareStreamsAndStart(
> >>>> JUnitStarter.java:242)
> >>>> at com.intellij.rt.execution.junit.JUnitStarter.main(
> >>>> JUnitStarter.java:70)
> >>>>
> >>>> Replacing the addFilter line with
> >>>>
> >>>> cb.addFilter("1 > ?y");
> >>>>
> >>>> does not fail, terminating with the expected print-out
> >>>> of a construct query
> >>>>
> >>>> CONSTRUCT
> >>>> {
> >>>> }
> >>>> WHERE
> >>>> { FILTER ( 1 > ?y )}
> >>>>
> >>>> I tried poking around with the debugger but couldn't see anyhting
> >>>> obvious. However, /sometimes/ stepping through the code
> >>>> results in it working and sometimes not, presumably depending
> >>>> on exactly when I give up through-stepping.
> >>>>
> >>>> Am I doing anything obviously wrong (like misunderstanding
> >>>> how to use the Expr functionality) or should I file a JIRA?
> >>>> This is Jena 3.4.0.
> >>>>
> >>>> Chris
> >>>>
> >>>>
> >>>>
> >>>>
> >>>> --
> >>>> "What I don't understand is this ..." Trevor Chaplin, /The
> Beiderbeck
> >>>> Affair/
> >>>>
> >>>> Epimorphics Ltd, http://www.epimorphics.com
> >>>> Registered address: Court Lodge, 105 High Street, Portishead, Bristol
> >>>> BS20
> >>>> 6PT
> >>>> Epimorphics Ltd. is a limited company registered in England (number
> >>>> 7016688)
> >>>>
> >>>>
> >>>
> >>>
> >>>
> >
> >
> > --
> > I like: Like Like - The likeliest place on the web
> > <http://like-like.xenei.com>
> > LinkedIn: http://www.linkedin.com/in/claudewarren
> >
>
>
>
> --
> I like: Like Like - The likeliest place on the web
> <http://like-like.xenei.com>
> LinkedIn: http://www.linkedin.com/in/claudewarren
>
--
"What I don't understand is this ..." Trevor Chaplin, /The Beiderbeck
Affair/
Epimorphics Ltd, http://www.epimorphics.com
Registered address: Court Lodge, 105 High Street, Portishead, Bristol BS20
6PT
Epimorphics Ltd. is a limited company registered in England (number 7016688)
Re: problem with query builder
Posted by Claude Warren <cl...@xenei.com>.
Fix coming shortly but the work around is...
change:
Expr x = new NodeValueInteger(1)
to:
NodeValue nv = new NodeValueInteger(1)
nv.asNode()
Expr x = nv;
Claude
On Sat, Nov 18, 2017 at 3:48 PM, Claude Warren <cl...@xenei.com> wrote:
> Well done Andy. Right on the money, exactly what I discovered.
>
> On Sat, Nov 18, 2017 at 3:39 PM, Andy Seaborne <an...@apache.org> wrote:
>
>> c.f. NodeValue.getNode and NodeValue.asNode
>>
>> Presumably something calls getNode when it wanted asNode.
>>
>>
>> On 18/11/17 15:36, Claude Warren wrote:
>>
>>> This is a bug. The problem is that new NodeValueInteger(1);
>>> does not set the Node value that the rewriter is trying to rewrite and
>>> thus
>>> the null pointer exception.
>>>
>>> I will get a fix out shortly.
>>>
>>> Claude
>>>
>>> On Fri, Nov 17, 2017 at 4:14 PM, Chris Dollin <
>>> chris.dollin@epimorphics.com>
>>> wrote:
>>>
>>> Hi,
>>>>
>>>> I was experimenting with the query builder and hit a problem
>>>> when I was attempting to construct an Expr. This example:
>>>>
>>>> package com.epimorphics.scratch;
>>>>
>>>> import org.apache.jena.arq.querybuilder.ConstructBuilder;
>>>> import org.apache.jena.sparql.expr.E_GreaterThan;
>>>> import org.apache.jena.sparql.expr.Expr;
>>>> import org.apache.jena.sparql.expr.ExprVar;
>>>> import org.apache.jena.sparql.expr.nodevalue.NodeValueInteger;
>>>> import org.junit.Test;
>>>>
>>>> public class Example {
>>>>
>>>> @Test public void tryBuilding() {
>>>> ConstructBuilder cb = new ConstructBuilder();
>>>>
>>>> Expr x = new NodeValueInteger(1);
>>>> Expr y = new ExprVar("y");
>>>> Expr e = new E_GreaterThan(x, y);
>>>> cb.addFilter(e);
>>>> System.err.println(cb.buildString());
>>>> }
>>>> }
>>>>
>>>> when run fails with a null pointer exception:
>>>>
>>>> java.lang.NullPointerException
>>>> at org.apache.jena.arq.querybuilder.rewriters.
>>>> AbstractRewriter.changeNode(AbstractRewriter.java:126)
>>>> at org.apache.jena.arq.querybuilder.rewriters.NodeValueRewriter
>>>> .visit(
>>>> NodeValueRewriter.java:64)
>>>> at org.apache.jena.sparql.expr.nodevalue.NodeValueInteger.
>>>> visit(NodeValueInteger.java:78)
>>>> at org.apache.jena.arq.querybuilder.rewriters.ExprRewriter.visit(
>>>> ExprRewriter.java:127)
>>>> at org.apache.jena.sparql.expr.NodeValue.visit(NodeValue.java:1
>>>> 205)
>>>> at org.apache.jena.arq.querybuilder.rewriters.ExprRewriter.visit(
>>>> ExprRewriter.java:65)
>>>> at org.apache.jena.sparql.expr.ExprFunction2.visit(
>>>> ExprFunction2.java:109)
>>>> at org.apache.jena.arq.querybuilder.rewriters.ElementRewriter.v
>>>> isit(
>>>> ElementRewriter.java:70)
>>>> at org.apache.jena.sparql.syntax.ElementFilter.visit(
>>>> ElementFilter.java:35)
>>>> at org.apache.jena.arq.querybuilder.rewriters.ElementRewriter.v
>>>> isit(
>>>> ElementRewriter.java:141)
>>>> at org.apache.jena.sparql.syntax.ElementGroup.visit(
>>>> ElementGroup.java:120)
>>>> at org.apache.jena.arq.querybuilder.handlers.WhereHandler.addAll(
>>>> WhereHandler.java:81)
>>>> at org.apache.jena.arq.querybuilder.handlers.HandlerBlock.addAll(
>>>> HandlerBlock.java:218)
>>>> at org.apache.jena.arq.querybuilder.handlers.HandlerBlock.addAll(
>>>> HandlerBlock.java:245)
>>>> at org.apache.jena.arq.querybuilder.AbstractQueryBuilder.build(
>>>> AbstractQueryBuilder.java:555)
>>>> at org.apache.jena.arq.querybuilder.AbstractQueryBuilder.buildS
>>>> tring(
>>>> AbstractQueryBuilder.java:522)
>>>> at com.epimorphics.scratch.Example.tryBuilding(Example.java:20)
>>>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>>>> at sun.reflect.NativeMethodAccessorImpl.invoke(
>>>> NativeMethodAccessorImpl.java:62)
>>>> at sun.reflect.DelegatingMethodAccessorImpl.invoke(
>>>> DelegatingMethodAccessorImpl.java:43)
>>>> at java.lang.reflect.Method.invoke(Method.java:498)
>>>> at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(
>>>> FrameworkMethod.java:47)
>>>> at org.junit.internal.runners.model.ReflectiveCallable.run(
>>>> ReflectiveCallable.java:12)
>>>> at org.junit.runners.model.FrameworkMethod.invokeExplosively(
>>>> FrameworkMethod.java:44)
>>>> at org.junit.internal.runners.statements.InvokeMethod.
>>>> evaluate(InvokeMethod.java:17)
>>>> at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
>>>> at org.junit.runners.BlockJUnit4ClassRunner.runChild(
>>>> BlockJUnit4ClassRunner.java:70)
>>>> at org.junit.runners.BlockJUnit4ClassRunner.runChild(
>>>> BlockJUnit4ClassRunner.java:50)
>>>> at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
>>>> at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
>>>> at org.junit.runners.ParentRunner.runChildren(ParentRunner.java
>>>> :236)
>>>> at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
>>>> at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:
>>>> 229)
>>>> at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
>>>> at org.junit.runner.JUnitCore.run(JUnitCore.java:160)
>>>> at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(
>>>> JUnit4IdeaTestRunner.java:68)
>>>> at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.
>>>> startRunnerWithArgs(IdeaTestRunner.java:47)
>>>> at com.intellij.rt.execution.junit.JUnitStarter.
>>>> prepareStreamsAndStart(
>>>> JUnitStarter.java:242)
>>>> at com.intellij.rt.execution.junit.JUnitStarter.main(
>>>> JUnitStarter.java:70)
>>>>
>>>> Replacing the addFilter line with
>>>>
>>>> cb.addFilter("1 > ?y");
>>>>
>>>> does not fail, terminating with the expected print-out
>>>> of a construct query
>>>>
>>>> CONSTRUCT
>>>> {
>>>> }
>>>> WHERE
>>>> { FILTER ( 1 > ?y )}
>>>>
>>>> I tried poking around with the debugger but couldn't see anyhting
>>>> obvious. However, /sometimes/ stepping through the code
>>>> results in it working and sometimes not, presumably depending
>>>> on exactly when I give up through-stepping.
>>>>
>>>> Am I doing anything obviously wrong (like misunderstanding
>>>> how to use the Expr functionality) or should I file a JIRA?
>>>> This is Jena 3.4.0.
>>>>
>>>> Chris
>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> "What I don't understand is this ..." Trevor Chaplin, /The Beiderbeck
>>>> Affair/
>>>>
>>>> Epimorphics Ltd, http://www.epimorphics.com
>>>> Registered address: Court Lodge, 105 High Street, Portishead, Bristol
>>>> BS20
>>>> 6PT
>>>> Epimorphics Ltd. is a limited company registered in England (number
>>>> 7016688)
>>>>
>>>>
>>>
>>>
>>>
>
>
> --
> I like: Like Like - The likeliest place on the web
> <http://like-like.xenei.com>
> LinkedIn: http://www.linkedin.com/in/claudewarren
>
--
I like: Like Like - The likeliest place on the web
<http://like-like.xenei.com>
LinkedIn: http://www.linkedin.com/in/claudewarren
Re: problem with query builder
Posted by Claude Warren <cl...@xenei.com>.
Well done Andy. Right on the money, exactly what I discovered.
On Sat, Nov 18, 2017 at 3:39 PM, Andy Seaborne <an...@apache.org> wrote:
> c.f. NodeValue.getNode and NodeValue.asNode
>
> Presumably something calls getNode when it wanted asNode.
>
>
> On 18/11/17 15:36, Claude Warren wrote:
>
>> This is a bug. The problem is that new NodeValueInteger(1);
>> does not set the Node value that the rewriter is trying to rewrite and
>> thus
>> the null pointer exception.
>>
>> I will get a fix out shortly.
>>
>> Claude
>>
>> On Fri, Nov 17, 2017 at 4:14 PM, Chris Dollin <
>> chris.dollin@epimorphics.com>
>> wrote:
>>
>> Hi,
>>>
>>> I was experimenting with the query builder and hit a problem
>>> when I was attempting to construct an Expr. This example:
>>>
>>> package com.epimorphics.scratch;
>>>
>>> import org.apache.jena.arq.querybuilder.ConstructBuilder;
>>> import org.apache.jena.sparql.expr.E_GreaterThan;
>>> import org.apache.jena.sparql.expr.Expr;
>>> import org.apache.jena.sparql.expr.ExprVar;
>>> import org.apache.jena.sparql.expr.nodevalue.NodeValueInteger;
>>> import org.junit.Test;
>>>
>>> public class Example {
>>>
>>> @Test public void tryBuilding() {
>>> ConstructBuilder cb = new ConstructBuilder();
>>>
>>> Expr x = new NodeValueInteger(1);
>>> Expr y = new ExprVar("y");
>>> Expr e = new E_GreaterThan(x, y);
>>> cb.addFilter(e);
>>> System.err.println(cb.buildString());
>>> }
>>> }
>>>
>>> when run fails with a null pointer exception:
>>>
>>> java.lang.NullPointerException
>>> at org.apache.jena.arq.querybuilder.rewriters.
>>> AbstractRewriter.changeNode(AbstractRewriter.java:126)
>>> at org.apache.jena.arq.querybuilder.rewriters.NodeValueRewriter
>>> .visit(
>>> NodeValueRewriter.java:64)
>>> at org.apache.jena.sparql.expr.nodevalue.NodeValueInteger.
>>> visit(NodeValueInteger.java:78)
>>> at org.apache.jena.arq.querybuilder.rewriters.ExprRewriter.visit(
>>> ExprRewriter.java:127)
>>> at org.apache.jena.sparql.expr.NodeValue.visit(NodeValue.java:1205)
>>> at org.apache.jena.arq.querybuilder.rewriters.ExprRewriter.visit(
>>> ExprRewriter.java:65)
>>> at org.apache.jena.sparql.expr.ExprFunction2.visit(
>>> ExprFunction2.java:109)
>>> at org.apache.jena.arq.querybuilder.rewriters.ElementRewriter.
>>> visit(
>>> ElementRewriter.java:70)
>>> at org.apache.jena.sparql.syntax.ElementFilter.visit(
>>> ElementFilter.java:35)
>>> at org.apache.jena.arq.querybuilder.rewriters.ElementRewriter.
>>> visit(
>>> ElementRewriter.java:141)
>>> at org.apache.jena.sparql.syntax.ElementGroup.visit(
>>> ElementGroup.java:120)
>>> at org.apache.jena.arq.querybuilder.handlers.WhereHandler.addAll(
>>> WhereHandler.java:81)
>>> at org.apache.jena.arq.querybuilder.handlers.HandlerBlock.addAll(
>>> HandlerBlock.java:218)
>>> at org.apache.jena.arq.querybuilder.handlers.HandlerBlock.addAll(
>>> HandlerBlock.java:245)
>>> at org.apache.jena.arq.querybuilder.AbstractQueryBuilder.build(
>>> AbstractQueryBuilder.java:555)
>>> at org.apache.jena.arq.querybuilder.AbstractQueryBuilder.buildS
>>> tring(
>>> AbstractQueryBuilder.java:522)
>>> at com.epimorphics.scratch.Example.tryBuilding(Example.java:20)
>>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>>> at sun.reflect.NativeMethodAccessorImpl.invoke(
>>> NativeMethodAccessorImpl.java:62)
>>> at sun.reflect.DelegatingMethodAccessorImpl.invoke(
>>> DelegatingMethodAccessorImpl.java:43)
>>> at java.lang.reflect.Method.invoke(Method.java:498)
>>> at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(
>>> FrameworkMethod.java:47)
>>> at org.junit.internal.runners.model.ReflectiveCallable.run(
>>> ReflectiveCallable.java:12)
>>> at org.junit.runners.model.FrameworkMethod.invokeExplosively(
>>> FrameworkMethod.java:44)
>>> at org.junit.internal.runners.statements.InvokeMethod.
>>> evaluate(InvokeMethod.java:17)
>>> at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
>>> at org.junit.runners.BlockJUnit4ClassRunner.runChild(
>>> BlockJUnit4ClassRunner.java:70)
>>> at org.junit.runners.BlockJUnit4ClassRunner.runChild(
>>> BlockJUnit4ClassRunner.java:50)
>>> at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
>>> at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
>>> at org.junit.runners.ParentRunner.runChildren(ParentRunner.
>>> java:236)
>>> at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
>>> at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
>>> at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
>>> at org.junit.runner.JUnitCore.run(JUnitCore.java:160)
>>> at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(
>>> JUnit4IdeaTestRunner.java:68)
>>> at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.
>>> startRunnerWithArgs(IdeaTestRunner.java:47)
>>> at com.intellij.rt.execution.junit.JUnitStarter.
>>> prepareStreamsAndStart(
>>> JUnitStarter.java:242)
>>> at com.intellij.rt.execution.junit.JUnitStarter.main(
>>> JUnitStarter.java:70)
>>>
>>> Replacing the addFilter line with
>>>
>>> cb.addFilter("1 > ?y");
>>>
>>> does not fail, terminating with the expected print-out
>>> of a construct query
>>>
>>> CONSTRUCT
>>> {
>>> }
>>> WHERE
>>> { FILTER ( 1 > ?y )}
>>>
>>> I tried poking around with the debugger but couldn't see anyhting
>>> obvious. However, /sometimes/ stepping through the code
>>> results in it working and sometimes not, presumably depending
>>> on exactly when I give up through-stepping.
>>>
>>> Am I doing anything obviously wrong (like misunderstanding
>>> how to use the Expr functionality) or should I file a JIRA?
>>> This is Jena 3.4.0.
>>>
>>> Chris
>>>
>>>
>>>
>>>
>>> --
>>> "What I don't understand is this ..." Trevor Chaplin, /The Beiderbeck
>>> Affair/
>>>
>>> Epimorphics Ltd, http://www.epimorphics.com
>>> Registered address: Court Lodge, 105 High Street, Portishead, Bristol
>>> BS20
>>> 6PT
>>> Epimorphics Ltd. is a limited company registered in England (number
>>> 7016688)
>>>
>>>
>>
>>
>>
--
I like: Like Like - The likeliest place on the web
<http://like-like.xenei.com>
LinkedIn: http://www.linkedin.com/in/claudewarren
Re: problem with query builder
Posted by Andy Seaborne <an...@apache.org>.
c.f. NodeValue.getNode and NodeValue.asNode
Presumably something calls getNode when it wanted asNode.
On 18/11/17 15:36, Claude Warren wrote:
> This is a bug. The problem is that new NodeValueInteger(1);
> does not set the Node value that the rewriter is trying to rewrite and thus
> the null pointer exception.
>
> I will get a fix out shortly.
>
> Claude
>
> On Fri, Nov 17, 2017 at 4:14 PM, Chris Dollin <ch...@epimorphics.com>
> wrote:
>
>> Hi,
>>
>> I was experimenting with the query builder and hit a problem
>> when I was attempting to construct an Expr. This example:
>>
>> package com.epimorphics.scratch;
>>
>> import org.apache.jena.arq.querybuilder.ConstructBuilder;
>> import org.apache.jena.sparql.expr.E_GreaterThan;
>> import org.apache.jena.sparql.expr.Expr;
>> import org.apache.jena.sparql.expr.ExprVar;
>> import org.apache.jena.sparql.expr.nodevalue.NodeValueInteger;
>> import org.junit.Test;
>>
>> public class Example {
>>
>> @Test public void tryBuilding() {
>> ConstructBuilder cb = new ConstructBuilder();
>>
>> Expr x = new NodeValueInteger(1);
>> Expr y = new ExprVar("y");
>> Expr e = new E_GreaterThan(x, y);
>> cb.addFilter(e);
>> System.err.println(cb.buildString());
>> }
>> }
>>
>> when run fails with a null pointer exception:
>>
>> java.lang.NullPointerException
>> at org.apache.jena.arq.querybuilder.rewriters.
>> AbstractRewriter.changeNode(AbstractRewriter.java:126)
>> at org.apache.jena.arq.querybuilder.rewriters.NodeValueRewriter.visit(
>> NodeValueRewriter.java:64)
>> at org.apache.jena.sparql.expr.nodevalue.NodeValueInteger.
>> visit(NodeValueInteger.java:78)
>> at org.apache.jena.arq.querybuilder.rewriters.ExprRewriter.visit(
>> ExprRewriter.java:127)
>> at org.apache.jena.sparql.expr.NodeValue.visit(NodeValue.java:1205)
>> at org.apache.jena.arq.querybuilder.rewriters.ExprRewriter.visit(
>> ExprRewriter.java:65)
>> at org.apache.jena.sparql.expr.ExprFunction2.visit(
>> ExprFunction2.java:109)
>> at org.apache.jena.arq.querybuilder.rewriters.ElementRewriter.visit(
>> ElementRewriter.java:70)
>> at org.apache.jena.sparql.syntax.ElementFilter.visit(
>> ElementFilter.java:35)
>> at org.apache.jena.arq.querybuilder.rewriters.ElementRewriter.visit(
>> ElementRewriter.java:141)
>> at org.apache.jena.sparql.syntax.ElementGroup.visit(
>> ElementGroup.java:120)
>> at org.apache.jena.arq.querybuilder.handlers.WhereHandler.addAll(
>> WhereHandler.java:81)
>> at org.apache.jena.arq.querybuilder.handlers.HandlerBlock.addAll(
>> HandlerBlock.java:218)
>> at org.apache.jena.arq.querybuilder.handlers.HandlerBlock.addAll(
>> HandlerBlock.java:245)
>> at org.apache.jena.arq.querybuilder.AbstractQueryBuilder.build(
>> AbstractQueryBuilder.java:555)
>> at org.apache.jena.arq.querybuilder.AbstractQueryBuilder.buildString(
>> AbstractQueryBuilder.java:522)
>> at com.epimorphics.scratch.Example.tryBuilding(Example.java:20)
>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>> at sun.reflect.NativeMethodAccessorImpl.invoke(
>> NativeMethodAccessorImpl.java:62)
>> at sun.reflect.DelegatingMethodAccessorImpl.invoke(
>> DelegatingMethodAccessorImpl.java:43)
>> at java.lang.reflect.Method.invoke(Method.java:498)
>> at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(
>> FrameworkMethod.java:47)
>> at org.junit.internal.runners.model.ReflectiveCallable.run(
>> ReflectiveCallable.java:12)
>> at org.junit.runners.model.FrameworkMethod.invokeExplosively(
>> FrameworkMethod.java:44)
>> at org.junit.internal.runners.statements.InvokeMethod.
>> evaluate(InvokeMethod.java:17)
>> at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
>> at org.junit.runners.BlockJUnit4ClassRunner.runChild(
>> BlockJUnit4ClassRunner.java:70)
>> at org.junit.runners.BlockJUnit4ClassRunner.runChild(
>> BlockJUnit4ClassRunner.java:50)
>> at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
>> at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
>> at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
>> at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
>> at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
>> at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
>> at org.junit.runner.JUnitCore.run(JUnitCore.java:160)
>> at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(
>> JUnit4IdeaTestRunner.java:68)
>> at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.
>> startRunnerWithArgs(IdeaTestRunner.java:47)
>> at com.intellij.rt.execution.junit.JUnitStarter.
>> prepareStreamsAndStart(
>> JUnitStarter.java:242)
>> at com.intellij.rt.execution.junit.JUnitStarter.main(
>> JUnitStarter.java:70)
>>
>> Replacing the addFilter line with
>>
>> cb.addFilter("1 > ?y");
>>
>> does not fail, terminating with the expected print-out
>> of a construct query
>>
>> CONSTRUCT
>> {
>> }
>> WHERE
>> { FILTER ( 1 > ?y )}
>>
>> I tried poking around with the debugger but couldn't see anyhting
>> obvious. However, /sometimes/ stepping through the code
>> results in it working and sometimes not, presumably depending
>> on exactly when I give up through-stepping.
>>
>> Am I doing anything obviously wrong (like misunderstanding
>> how to use the Expr functionality) or should I file a JIRA?
>> This is Jena 3.4.0.
>>
>> Chris
>>
>>
>>
>>
>> --
>> "What I don't understand is this ..." Trevor Chaplin, /The Beiderbeck
>> Affair/
>>
>> Epimorphics Ltd, http://www.epimorphics.com
>> Registered address: Court Lodge, 105 High Street, Portishead, Bristol BS20
>> 6PT
>> Epimorphics Ltd. is a limited company registered in England (number
>> 7016688)
>>
>
>
>
Re: problem with query builder
Posted by Claude Warren <cl...@xenei.com>.
This is a bug. The problem is that new NodeValueInteger(1);
does not set the Node value that the rewriter is trying to rewrite and thus
the null pointer exception.
I will get a fix out shortly.
Claude
On Fri, Nov 17, 2017 at 4:14 PM, Chris Dollin <ch...@epimorphics.com>
wrote:
> Hi,
>
> I was experimenting with the query builder and hit a problem
> when I was attempting to construct an Expr. This example:
>
> package com.epimorphics.scratch;
>
> import org.apache.jena.arq.querybuilder.ConstructBuilder;
> import org.apache.jena.sparql.expr.E_GreaterThan;
> import org.apache.jena.sparql.expr.Expr;
> import org.apache.jena.sparql.expr.ExprVar;
> import org.apache.jena.sparql.expr.nodevalue.NodeValueInteger;
> import org.junit.Test;
>
> public class Example {
>
> @Test public void tryBuilding() {
> ConstructBuilder cb = new ConstructBuilder();
>
> Expr x = new NodeValueInteger(1);
> Expr y = new ExprVar("y");
> Expr e = new E_GreaterThan(x, y);
> cb.addFilter(e);
> System.err.println(cb.buildString());
> }
> }
>
> when run fails with a null pointer exception:
>
> java.lang.NullPointerException
> at org.apache.jena.arq.querybuilder.rewriters.
> AbstractRewriter.changeNode(AbstractRewriter.java:126)
> at org.apache.jena.arq.querybuilder.rewriters.NodeValueRewriter.visit(
> NodeValueRewriter.java:64)
> at org.apache.jena.sparql.expr.nodevalue.NodeValueInteger.
> visit(NodeValueInteger.java:78)
> at org.apache.jena.arq.querybuilder.rewriters.ExprRewriter.visit(
> ExprRewriter.java:127)
> at org.apache.jena.sparql.expr.NodeValue.visit(NodeValue.java:1205)
> at org.apache.jena.arq.querybuilder.rewriters.ExprRewriter.visit(
> ExprRewriter.java:65)
> at org.apache.jena.sparql.expr.ExprFunction2.visit(
> ExprFunction2.java:109)
> at org.apache.jena.arq.querybuilder.rewriters.ElementRewriter.visit(
> ElementRewriter.java:70)
> at org.apache.jena.sparql.syntax.ElementFilter.visit(
> ElementFilter.java:35)
> at org.apache.jena.arq.querybuilder.rewriters.ElementRewriter.visit(
> ElementRewriter.java:141)
> at org.apache.jena.sparql.syntax.ElementGroup.visit(
> ElementGroup.java:120)
> at org.apache.jena.arq.querybuilder.handlers.WhereHandler.addAll(
> WhereHandler.java:81)
> at org.apache.jena.arq.querybuilder.handlers.HandlerBlock.addAll(
> HandlerBlock.java:218)
> at org.apache.jena.arq.querybuilder.handlers.HandlerBlock.addAll(
> HandlerBlock.java:245)
> at org.apache.jena.arq.querybuilder.AbstractQueryBuilder.build(
> AbstractQueryBuilder.java:555)
> at org.apache.jena.arq.querybuilder.AbstractQueryBuilder.buildString(
> AbstractQueryBuilder.java:522)
> at com.epimorphics.scratch.Example.tryBuilding(Example.java:20)
> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> at sun.reflect.NativeMethodAccessorImpl.invoke(
> NativeMethodAccessorImpl.java:62)
> at sun.reflect.DelegatingMethodAccessorImpl.invoke(
> DelegatingMethodAccessorImpl.java:43)
> at java.lang.reflect.Method.invoke(Method.java:498)
> at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(
> FrameworkMethod.java:47)
> at org.junit.internal.runners.model.ReflectiveCallable.run(
> ReflectiveCallable.java:12)
> at org.junit.runners.model.FrameworkMethod.invokeExplosively(
> FrameworkMethod.java:44)
> at org.junit.internal.runners.statements.InvokeMethod.
> evaluate(InvokeMethod.java:17)
> at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
> at org.junit.runners.BlockJUnit4ClassRunner.runChild(
> BlockJUnit4ClassRunner.java:70)
> at org.junit.runners.BlockJUnit4ClassRunner.runChild(
> BlockJUnit4ClassRunner.java:50)
> at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
> at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
> at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
> at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
> at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
> at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
> at org.junit.runner.JUnitCore.run(JUnitCore.java:160)
> at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(
> JUnit4IdeaTestRunner.java:68)
> at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.
> startRunnerWithArgs(IdeaTestRunner.java:47)
> at com.intellij.rt.execution.junit.JUnitStarter.
> prepareStreamsAndStart(
> JUnitStarter.java:242)
> at com.intellij.rt.execution.junit.JUnitStarter.main(
> JUnitStarter.java:70)
>
> Replacing the addFilter line with
>
> cb.addFilter("1 > ?y");
>
> does not fail, terminating with the expected print-out
> of a construct query
>
> CONSTRUCT
> {
> }
> WHERE
> { FILTER ( 1 > ?y )}
>
> I tried poking around with the debugger but couldn't see anyhting
> obvious. However, /sometimes/ stepping through the code
> results in it working and sometimes not, presumably depending
> on exactly when I give up through-stepping.
>
> Am I doing anything obviously wrong (like misunderstanding
> how to use the Expr functionality) or should I file a JIRA?
> This is Jena 3.4.0.
>
> Chris
>
>
>
>
> --
> "What I don't understand is this ..." Trevor Chaplin, /The Beiderbeck
> Affair/
>
> Epimorphics Ltd, http://www.epimorphics.com
> Registered address: Court Lodge, 105 High Street, Portishead, Bristol BS20
> 6PT
> Epimorphics Ltd. is a limited company registered in England (number
> 7016688)
>
--
I like: Like Like - The likeliest place on the web
<http://like-like.xenei.com>
LinkedIn: http://www.linkedin.com/in/claudewarren