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Posted to users@sling.apache.org by Roger Reed <Ro...@yahoo.com> on 2011/12/03 02:52:21 UTC
JsonQueryServlet NullPointerException on Simple XPATH Query
Hello,
I¹m getting a NullPointerException when executing a simple XPATH query via
the JsonQueryServlet. How stable is the JsonQueryServlet? I¹m using the
servlet in version 6 WAR. This does work fine when I have different/less
data in the repository.
Thanks,
Roger
http://localhost:7070/sling/content.query.json?queryType=xpath&statement=//*
[@jcr:primaryType='test:imageReference']
java.lang.NullPointerException
at
org.apache.sling.servlets.get.impl.JsonQueryServlet.dumpResult(JsonQueryServ
let.java:193)
at
org.apache.sling.servlets.get.impl.JsonQueryServlet.doGet(JsonQueryServlet.j
ava:106)
at
org.apache.sling.api.servlets.SlingSafeMethodsServlet.mayService(SlingSafeMe
thodsServlet.java:268)
at
org.apache.sling.api.servlets.SlingSafeMethodsServlet.service(SlingSafeMetho
dsServlet.java:344)
at
org.apache.sling.api.servlets.SlingSafeMethodsServlet.service(SlingSafeMetho
dsServlet.java:375)
at
org.apache.sling.engine.impl.request.RequestData.service(RequestData.java:52
9)
at
org.apache.sling.engine.impl.SlingRequestProcessorImpl.processComponent(Slin
gRequestProcessorImpl.java:274)
at
org.apache.sling.engine.impl.filter.RequestSlingFilterChain.render(RequestSl
ingFilterChain.java:49)
at
org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(Abstra
ctSlingFilterChain.java:64)
at
org.apache.sling.engine.impl.debug.RequestProgressTrackerLogFilter.doFilter(
RequestProgressTrackerLogFilter.java:59)
at
org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(Abstra
ctSlingFilterChain.java:60)
at
org.apache.sling.engine.impl.SlingRequestProcessorImpl.processRequest(SlingR
equestProcessorImpl.java:161)
at
org.apache.sling.engine.impl.SlingMainServlet.service(SlingMainServlet.java:
183)
at
org.apache.felix.http.base.internal.handler.ServletHandler.doHandle(ServletH
andler.java:96)
at
org.apache.felix.http.base.internal.handler.ServletHandler.handle(ServletHan
dler.java:79)
at
org.apache.felix.http.base.internal.dispatch.ServletPipeline.handle(ServletP
ipeline.java:42)
at
org.apache.felix.http.base.internal.dispatch.InvocationFilterChain.doFilter(
InvocationFilterChain.java:49)
at
org.apache.felix.http.base.internal.dispatch.HttpFilterChain.doFilter(HttpFi
lterChain.java:33)
at
org.apache.felix.http.base.internal.dispatch.FilterPipeline.dispatch(FilterP
ipeline.java:48)
at
org.apache.felix.http.base.internal.dispatch.Dispatcher.dispatch(Dispatcher.
java:39)
at
org.apache.felix.http.base.internal.DispatcherServlet.service(DispatcherServ
let.java:67)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at
org.apache.felix.http.proxy.ProxyServlet.service(ProxyServlet.java:60)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at
org.apache.sling.launchpad.base.webapp.SlingServletDelegate.service(SlingSer
vletDelegate.java:277)
at
org.apache.sling.launchpad.webapp.SlingServlet.service(SlingServlet.java:148
)
at
weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSe
curityHelper.java:227)
at
weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelpe
r.java:125)
at
weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:292)
at
weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:175)
at
weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(W
ebAppServletContext.java:3498)
at
weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubjec
t.java:321)
at weblogic.security.service.SecurityManager.runAs(Unknown Source)
at
weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletC
ontext.java:2180)
at
weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.
java:2086)
at
weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:140
6)
at weblogic.work.ExecuteThread.execute(ExecuteThread.java:201)
at weblogic.work.ExecuteThread.run(ExecuteThread.java:173)
Re: JsonQueryServlet NullPointerException on Simple XPATH Query
Posted by Roger Reed <Ro...@yahoo.com>.
Hey Eric,
Thanks for the clarification. That makes sense. Good reason for moving it
out of default install.
Cheers,
Roger
On 12/5/11 9:29 PM, "Eric Norman" <er...@gmail.com> wrote:
> Hi Roger,
>
> For your reference, the discussion related to discouraging the query
> servlet is at [1]. So basically the query servlet has been moved to a
> compatibility bundle that will not be installed by default, but if you
> really need it you can still install it.
>
> Allowing the full query string to be supplied as a request parameter can be
> easily abused to do denial-of-service or unintended information
> disclosure attack.
>
> 1. http://markmail.org/message/sxurvywelnyt3ntz
>
>
> On Mon, Dec 5, 2011 at 5:21 PM, Roger Reed <Ro...@yahoo.com> wrote:
>
>> Thanks for pointing me to the related JIRA ticket.
>>
>> I'm assuming the get servlets are still safe to use, and those are the only
>> available servlets that come with the default Sling install.
>>
>> Are there any plans to add a working query servlet? I think a query
>> servlet
>> with the ability to output entire nodes' as JSON, and not just the path,
>> would be very useful.
>>
>>
>> On 12/4/11 12:20 PM, "Eric Norman" <er...@gmail.com> wrote:
>>
>>> Per SLING-2226 (see [1] ) usage of the JsonQueryServlet is discouraged.
>>>
>>> As to the cause of this NPE, I believe [2] is the revision of that class
>>> that you are using. On line 193 of that file where the NPE was thrown,
>> it
>>> looks like either the row returned by the query was null or the row
>> didn't
>>> have a 'jcr:path' column value for some reason. You may be able to tell
>>> for sure by attaching a java debugger to the sling process.
>>>
>>> I also see some code changes for SLING-1533 [3] that injects the
>> 'jcr:path'
>>> if it is missing from the column list, so perhaps your problem is related
>>> to what that was fixing.
>>>
>>> 1. https://issues.apache.org/jira/browse/SLING-2226
>>> 2.
>>>
>>
http://svn.apache.org/viewvc/sling/trunk/bundles/servlets/get/src/main/java/o>>
r
>>>
>>
g/apache/sling/servlets/get/impl/JsonQueryServlet.java?revision=983310&view=m>>
a
>>> rkup&pathrev=983310
>>> 3.
>>>
>>
https://fisheye6.atlassian.com/viewrep/sling/trunk/bundles/jcr/resource/src/m>>
a
>>>
>>
in/java/org/apache/sling/jcr/resource/internal/JcrResourceResolver.java?r1=11>>
3
>>> 1133&r2=1131257
>>>
>>> On Fri, Dec 2, 2011 at 5:52 PM, Roger Reed <Ro...@yahoo.com> wrote:
>>>
>>>> Hello,
>>>>
>>>> I¹m getting a NullPointerException when executing a simple XPATH query
>> via
>>>> the JsonQueryServlet. How stable is the JsonQueryServlet? I¹m using
>> the
>>>> servlet in version 6 WAR. This does work fine when I have
>> different/less
>>>> data in the repository.
>>>>
>>>> Thanks,
>>>>
>>>> Roger
>>>>
>>>>
>>>>
>>>>
>> http://localhost:7070/sling/content.query.json?queryType=xpath&statement=//*
>>>> [@jcr:primaryType='test:imageReference']
>>>>
>>>> java.lang.NullPointerException
>>>> at
>>>>
>>>>
>> org.apache.sling.servlets.get.impl.JsonQueryServlet.dumpResult(JsonQueryServ
>>>> let.java:193)
>>>> at
>>>>
>>>>
>> org.apache.sling.servlets.get.impl.JsonQueryServlet.doGet(JsonQueryServlet.j
>>>> ava:106)
>>>> at
>>>>
>>>>
>> org.apache.sling.api.servlets.SlingSafeMethodsServlet.mayService(SlingSafeMe
>>>> thodsServlet.java:268)
>>>> at
>>>>
>>>>
>> org.apache.sling.api.servlets.SlingSafeMethodsServlet.service(SlingSafeMetho
>>>> dsServlet.java:344)
>>>> at
>>>>
>>>>
>> org.apache.sling.api.servlets.SlingSafeMethodsServlet.service(SlingSafeMetho
>>>> dsServlet.java:375)
>>>> at
>>>>
>>>>
>> org.apache.sling.engine.impl.request.RequestData.service(RequestData.java:52
>>>> 9)
>>>> at
>>>>
>>>>
>> org.apache.sling.engine.impl.SlingRequestProcessorImpl.processComponent(Slin
>>>> gRequestProcessorImpl.java:274)
>>>> at
>>>>
>>>>
>> org.apache.sling.engine.impl.filter.RequestSlingFilterChain.render(RequestSl
>>>> ingFilterChain.java:49)
>>>> at
>>>>
>>>>
>> org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(Abstra
>>>> ctSlingFilterChain.java:64)
>>>> at
>>>>
>>>>
>> org.apache.sling.engine.impl.debug.RequestProgressTrackerLogFilter.doFilter(
>>>> RequestProgressTrackerLogFilter.java:59)
>>>> at
>>>>
>>>>
>> org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(Abstra
>>>> ctSlingFilterChain.java:60)
>>>> at
>>>>
>>>>
>> org.apache.sling.engine.impl.SlingRequestProcessorImpl.processRequest(SlingR
>>>> equestProcessorImpl.java:161)
>>>> at
>>>>
>>>>
>> org.apache.sling.engine.impl.SlingMainServlet.service(SlingMainServlet.java:
>>>> 183)
>>>> at
>>>>
>>>>
>> org.apache.felix.http.base.internal.handler.ServletHandler.doHandle(ServletH
>>>> andler.java:96)
>>>> at
>>>>
>>>>
>> org.apache.felix.http.base.internal.handler.ServletHandler.handle(ServletHan
>>>> dler.java:79)
>>>> at
>>>>
>>>>
>> org.apache.felix.http.base.internal.dispatch.ServletPipeline.handle(ServletP
>>>> ipeline.java:42)
>>>> at
>>>>
>>>>
>> org.apache.felix.http.base.internal.dispatch.InvocationFilterChain.doFilter(
>>>> InvocationFilterChain.java:49)
>>>> at
>>>>
>>>>
>> org.apache.felix.http.base.internal.dispatch.HttpFilterChain.doFilter(HttpFi
>>>> lterChain.java:33)
>>>> at
>>>>
>>>>
>> org.apache.felix.http.base.internal.dispatch.FilterPipeline.dispatch(FilterP
>>>> ipeline.java:48)
>>>> at
>>>>
>>>>
>> org.apache.felix.http.base.internal.dispatch.Dispatcher.dispatch(Dispatcher.
>>>> java:39)
>>>> at
>>>>
>>>>
>> org.apache.felix.http.base.internal.DispatcherServlet.service(DispatcherServ
>>>> let.java:67)
>>>> at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
>>>> at
>>>> org.apache.felix.http.proxy.ProxyServlet.service(ProxyServlet.java:60)
>>>> at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
>>>> at
>>>>
>>>>
>> org.apache.sling.launchpad.base.webapp.SlingServletDelegate.service(SlingSer
>>>> vletDelegate.java:277)
>>>> at
>>>>
>>>>
>> org.apache.sling.launchpad.webapp.SlingServlet.service(SlingServlet.java:148
>>>> )
>>>> at
>>>>
>>>>
>> weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSe
>>>> curityHelper.java:227)
>>>> at
>>>>
>>>>
>> weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelpe
>>>> r.java:125)
>>>> at
>>>>
>> weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:292)
>>>> at
>>>>
>> weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:175)
>>>> at
>>>>
>>>>
>> weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(W
>>>> ebAppServletContext.java:3498)
>>>> at
>>>>
>>>>
>> weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubjec
>>>> t.java:321)
>>>> at weblogic.security.service.SecurityManager.runAs(Unknown Source)
>>>> at
>>>>
>>>>
>> weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletC
>>>> ontext.java:2180)
>>>> at
>>>>
>>>>
>> weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.
>>>> java:2086)
>>>> at
>>>>
>>>>
>> weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:140
>>>> 6)
>>>> at weblogic.work.ExecuteThread.execute(ExecuteThread.java:201)
>>>> at weblogic.work.ExecuteThread.run(ExecuteThread.java:173)
>>>>
>>>>
>>>>
>>>>
>>
>>
>>
Re: JsonQueryServlet NullPointerException on Simple XPATH Query
Posted by Eric Norman <er...@gmail.com>.
Hi Roger,
For your reference, the discussion related to discouraging the query
servlet is at [1]. So basically the query servlet has been moved to a
compatibility bundle that will not be installed by default, but if you
really need it you can still install it.
Allowing the full query string to be supplied as a request parameter can be
easily abused to do denial-of-service or unintended information
disclosure attack.
1. http://markmail.org/message/sxurvywelnyt3ntz
On Mon, Dec 5, 2011 at 5:21 PM, Roger Reed <Ro...@yahoo.com> wrote:
> Thanks for pointing me to the related JIRA ticket.
>
> I'm assuming the get servlets are still safe to use, and those are the only
> available servlets that come with the default Sling install.
>
> Are there any plans to add a working query servlet? I think a query
> servlet
> with the ability to output entire nodes' as JSON, and not just the path,
> would be very useful.
>
>
> On 12/4/11 12:20 PM, "Eric Norman" <er...@gmail.com> wrote:
>
> > Per SLING-2226 (see [1] ) usage of the JsonQueryServlet is discouraged.
> >
> > As to the cause of this NPE, I believe [2] is the revision of that class
> > that you are using. On line 193 of that file where the NPE was thrown,
> it
> > looks like either the row returned by the query was null or the row
> didn't
> > have a 'jcr:path' column value for some reason. You may be able to tell
> > for sure by attaching a java debugger to the sling process.
> >
> > I also see some code changes for SLING-1533 [3] that injects the
> 'jcr:path'
> > if it is missing from the column list, so perhaps your problem is related
> > to what that was fixing.
> >
> > 1. https://issues.apache.org/jira/browse/SLING-2226
> > 2.
> >
> http://svn.apache.org/viewvc/sling/trunk/bundles/servlets/get/src/main/java/or
> >
> g/apache/sling/servlets/get/impl/JsonQueryServlet.java?revision=983310&view=ma
> > rkup&pathrev=983310
> > 3.
> >
> https://fisheye6.atlassian.com/viewrep/sling/trunk/bundles/jcr/resource/src/ma
> >
> in/java/org/apache/sling/jcr/resource/internal/JcrResourceResolver.java?r1=113
> > 1133&r2=1131257
> >
> > On Fri, Dec 2, 2011 at 5:52 PM, Roger Reed <Ro...@yahoo.com> wrote:
> >
> >> Hello,
> >>
> >> I¹m getting a NullPointerException when executing a simple XPATH query
> via
> >> the JsonQueryServlet. How stable is the JsonQueryServlet? I¹m using
> the
> >> servlet in version 6 WAR. This does work fine when I have
> different/less
> >> data in the repository.
> >>
> >> Thanks,
> >>
> >> Roger
> >>
> >>
> >>
> >>
> http://localhost:7070/sling/content.query.json?queryType=xpath&statement=//*
> >> [@jcr:primaryType='test:imageReference']
> >>
> >> java.lang.NullPointerException
> >> at
> >>
> >>
> org.apache.sling.servlets.get.impl.JsonQueryServlet.dumpResult(JsonQueryServ
> >> let.java:193)
> >> at
> >>
> >>
> org.apache.sling.servlets.get.impl.JsonQueryServlet.doGet(JsonQueryServlet.j
> >> ava:106)
> >> at
> >>
> >>
> org.apache.sling.api.servlets.SlingSafeMethodsServlet.mayService(SlingSafeMe
> >> thodsServlet.java:268)
> >> at
> >>
> >>
> org.apache.sling.api.servlets.SlingSafeMethodsServlet.service(SlingSafeMetho
> >> dsServlet.java:344)
> >> at
> >>
> >>
> org.apache.sling.api.servlets.SlingSafeMethodsServlet.service(SlingSafeMetho
> >> dsServlet.java:375)
> >> at
> >>
> >>
> org.apache.sling.engine.impl.request.RequestData.service(RequestData.java:52
> >> 9)
> >> at
> >>
> >>
> org.apache.sling.engine.impl.SlingRequestProcessorImpl.processComponent(Slin
> >> gRequestProcessorImpl.java:274)
> >> at
> >>
> >>
> org.apache.sling.engine.impl.filter.RequestSlingFilterChain.render(RequestSl
> >> ingFilterChain.java:49)
> >> at
> >>
> >>
> org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(Abstra
> >> ctSlingFilterChain.java:64)
> >> at
> >>
> >>
> org.apache.sling.engine.impl.debug.RequestProgressTrackerLogFilter.doFilter(
> >> RequestProgressTrackerLogFilter.java:59)
> >> at
> >>
> >>
> org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(Abstra
> >> ctSlingFilterChain.java:60)
> >> at
> >>
> >>
> org.apache.sling.engine.impl.SlingRequestProcessorImpl.processRequest(SlingR
> >> equestProcessorImpl.java:161)
> >> at
> >>
> >>
> org.apache.sling.engine.impl.SlingMainServlet.service(SlingMainServlet.java:
> >> 183)
> >> at
> >>
> >>
> org.apache.felix.http.base.internal.handler.ServletHandler.doHandle(ServletH
> >> andler.java:96)
> >> at
> >>
> >>
> org.apache.felix.http.base.internal.handler.ServletHandler.handle(ServletHan
> >> dler.java:79)
> >> at
> >>
> >>
> org.apache.felix.http.base.internal.dispatch.ServletPipeline.handle(ServletP
> >> ipeline.java:42)
> >> at
> >>
> >>
> org.apache.felix.http.base.internal.dispatch.InvocationFilterChain.doFilter(
> >> InvocationFilterChain.java:49)
> >> at
> >>
> >>
> org.apache.felix.http.base.internal.dispatch.HttpFilterChain.doFilter(HttpFi
> >> lterChain.java:33)
> >> at
> >>
> >>
> org.apache.felix.http.base.internal.dispatch.FilterPipeline.dispatch(FilterP
> >> ipeline.java:48)
> >> at
> >>
> >>
> org.apache.felix.http.base.internal.dispatch.Dispatcher.dispatch(Dispatcher.
> >> java:39)
> >> at
> >>
> >>
> org.apache.felix.http.base.internal.DispatcherServlet.service(DispatcherServ
> >> let.java:67)
> >> at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
> >> at
> >> org.apache.felix.http.proxy.ProxyServlet.service(ProxyServlet.java:60)
> >> at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
> >> at
> >>
> >>
> org.apache.sling.launchpad.base.webapp.SlingServletDelegate.service(SlingSer
> >> vletDelegate.java:277)
> >> at
> >>
> >>
> org.apache.sling.launchpad.webapp.SlingServlet.service(SlingServlet.java:148
> >> )
> >> at
> >>
> >>
> weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSe
> >> curityHelper.java:227)
> >> at
> >>
> >>
> weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelpe
> >> r.java:125)
> >> at
> >>
> weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:292)
> >> at
> >>
> weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:175)
> >> at
> >>
> >>
> weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(W
> >> ebAppServletContext.java:3498)
> >> at
> >>
> >>
> weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubjec
> >> t.java:321)
> >> at weblogic.security.service.SecurityManager.runAs(Unknown Source)
> >> at
> >>
> >>
> weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletC
> >> ontext.java:2180)
> >> at
> >>
> >>
> weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.
> >> java:2086)
> >> at
> >>
> >>
> weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:140
> >> 6)
> >> at weblogic.work.ExecuteThread.execute(ExecuteThread.java:201)
> >> at weblogic.work.ExecuteThread.run(ExecuteThread.java:173)
> >>
> >>
> >>
> >>
>
>
>
Re: JsonQueryServlet NullPointerException on Simple XPATH Query
Posted by Roger Reed <Ro...@yahoo.com>.
Thanks for pointing me to the related JIRA ticket.
I'm assuming the get servlets are still safe to use, and those are the only
available servlets that come with the default Sling install.
Are there any plans to add a working query servlet? I think a query servlet
with the ability to output entire nodes' as JSON, and not just the path,
would be very useful.
On 12/4/11 12:20 PM, "Eric Norman" <er...@gmail.com> wrote:
> Per SLING-2226 (see [1] ) usage of the JsonQueryServlet is discouraged.
>
> As to the cause of this NPE, I believe [2] is the revision of that class
> that you are using. On line 193 of that file where the NPE was thrown, it
> looks like either the row returned by the query was null or the row didn't
> have a 'jcr:path' column value for some reason. You may be able to tell
> for sure by attaching a java debugger to the sling process.
>
> I also see some code changes for SLING-1533 [3] that injects the 'jcr:path'
> if it is missing from the column list, so perhaps your problem is related
> to what that was fixing.
>
> 1. https://issues.apache.org/jira/browse/SLING-2226
> 2.
> http://svn.apache.org/viewvc/sling/trunk/bundles/servlets/get/src/main/java/or
> g/apache/sling/servlets/get/impl/JsonQueryServlet.java?revision=983310&view=ma
> rkup&pathrev=983310
> 3.
> https://fisheye6.atlassian.com/viewrep/sling/trunk/bundles/jcr/resource/src/ma
> in/java/org/apache/sling/jcr/resource/internal/JcrResourceResolver.java?r1=113
> 1133&r2=1131257
>
> On Fri, Dec 2, 2011 at 5:52 PM, Roger Reed <Ro...@yahoo.com> wrote:
>
>> Hello,
>>
>> I¹m getting a NullPointerException when executing a simple XPATH query via
>> the JsonQueryServlet. How stable is the JsonQueryServlet? I¹m using the
>> servlet in version 6 WAR. This does work fine when I have different/less
>> data in the repository.
>>
>> Thanks,
>>
>> Roger
>>
>>
>>
>> http://localhost:7070/sling/content.query.json?queryType=xpath&statement=//*
>> [@jcr:primaryType='test:imageReference']
>>
>> java.lang.NullPointerException
>> at
>>
>> org.apache.sling.servlets.get.impl.JsonQueryServlet.dumpResult(JsonQueryServ
>> let.java:193)
>> at
>>
>> org.apache.sling.servlets.get.impl.JsonQueryServlet.doGet(JsonQueryServlet.j
>> ava:106)
>> at
>>
>> org.apache.sling.api.servlets.SlingSafeMethodsServlet.mayService(SlingSafeMe
>> thodsServlet.java:268)
>> at
>>
>> org.apache.sling.api.servlets.SlingSafeMethodsServlet.service(SlingSafeMetho
>> dsServlet.java:344)
>> at
>>
>> org.apache.sling.api.servlets.SlingSafeMethodsServlet.service(SlingSafeMetho
>> dsServlet.java:375)
>> at
>>
>> org.apache.sling.engine.impl.request.RequestData.service(RequestData.java:52
>> 9)
>> at
>>
>> org.apache.sling.engine.impl.SlingRequestProcessorImpl.processComponent(Slin
>> gRequestProcessorImpl.java:274)
>> at
>>
>> org.apache.sling.engine.impl.filter.RequestSlingFilterChain.render(RequestSl
>> ingFilterChain.java:49)
>> at
>>
>> org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(Abstra
>> ctSlingFilterChain.java:64)
>> at
>>
>> org.apache.sling.engine.impl.debug.RequestProgressTrackerLogFilter.doFilter(
>> RequestProgressTrackerLogFilter.java:59)
>> at
>>
>> org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(Abstra
>> ctSlingFilterChain.java:60)
>> at
>>
>> org.apache.sling.engine.impl.SlingRequestProcessorImpl.processRequest(SlingR
>> equestProcessorImpl.java:161)
>> at
>>
>> org.apache.sling.engine.impl.SlingMainServlet.service(SlingMainServlet.java:
>> 183)
>> at
>>
>> org.apache.felix.http.base.internal.handler.ServletHandler.doHandle(ServletH
>> andler.java:96)
>> at
>>
>> org.apache.felix.http.base.internal.handler.ServletHandler.handle(ServletHan
>> dler.java:79)
>> at
>>
>> org.apache.felix.http.base.internal.dispatch.ServletPipeline.handle(ServletP
>> ipeline.java:42)
>> at
>>
>> org.apache.felix.http.base.internal.dispatch.InvocationFilterChain.doFilter(
>> InvocationFilterChain.java:49)
>> at
>>
>> org.apache.felix.http.base.internal.dispatch.HttpFilterChain.doFilter(HttpFi
>> lterChain.java:33)
>> at
>>
>> org.apache.felix.http.base.internal.dispatch.FilterPipeline.dispatch(FilterP
>> ipeline.java:48)
>> at
>>
>> org.apache.felix.http.base.internal.dispatch.Dispatcher.dispatch(Dispatcher.
>> java:39)
>> at
>>
>> org.apache.felix.http.base.internal.DispatcherServlet.service(DispatcherServ
>> let.java:67)
>> at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
>> at
>> org.apache.felix.http.proxy.ProxyServlet.service(ProxyServlet.java:60)
>> at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
>> at
>>
>> org.apache.sling.launchpad.base.webapp.SlingServletDelegate.service(SlingSer
>> vletDelegate.java:277)
>> at
>>
>> org.apache.sling.launchpad.webapp.SlingServlet.service(SlingServlet.java:148
>> )
>> at
>>
>> weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSe
>> curityHelper.java:227)
>> at
>>
>> weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelpe
>> r.java:125)
>> at
>> weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:292)
>> at
>> weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:175)
>> at
>>
>> weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(W
>> ebAppServletContext.java:3498)
>> at
>>
>> weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubjec
>> t.java:321)
>> at weblogic.security.service.SecurityManager.runAs(Unknown Source)
>> at
>>
>> weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletC
>> ontext.java:2180)
>> at
>>
>> weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.
>> java:2086)
>> at
>>
>> weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:140
>> 6)
>> at weblogic.work.ExecuteThread.execute(ExecuteThread.java:201)
>> at weblogic.work.ExecuteThread.run(ExecuteThread.java:173)
>>
>>
>>
>>
Re: JsonQueryServlet NullPointerException on Simple XPATH Query
Posted by Eric Norman <er...@gmail.com>.
Per SLING-2226 (see [1] ) usage of the JsonQueryServlet is discouraged.
As to the cause of this NPE, I believe [2] is the revision of that class
that you are using. On line 193 of that file where the NPE was thrown, it
looks like either the row returned by the query was null or the row didn't
have a 'jcr:path' column value for some reason. You may be able to tell
for sure by attaching a java debugger to the sling process.
I also see some code changes for SLING-1533 [3] that injects the 'jcr:path'
if it is missing from the column list, so perhaps your problem is related
to what that was fixing.
1. https://issues.apache.org/jira/browse/SLING-2226
2.
http://svn.apache.org/viewvc/sling/trunk/bundles/servlets/get/src/main/java/org/apache/sling/servlets/get/impl/JsonQueryServlet.java?revision=983310&view=markup&pathrev=983310
3.
https://fisheye6.atlassian.com/viewrep/sling/trunk/bundles/jcr/resource/src/main/java/org/apache/sling/jcr/resource/internal/JcrResourceResolver.java?r1=1131133&r2=1131257
On Fri, Dec 2, 2011 at 5:52 PM, Roger Reed <Ro...@yahoo.com> wrote:
> Hello,
>
> I¹m getting a NullPointerException when executing a simple XPATH query via
> the JsonQueryServlet. How stable is the JsonQueryServlet? I¹m using the
> servlet in version 6 WAR. This does work fine when I have different/less
> data in the repository.
>
> Thanks,
>
> Roger
>
>
>
> http://localhost:7070/sling/content.query.json?queryType=xpath&statement=//*
> [@jcr:primaryType='test:imageReference']
>
> java.lang.NullPointerException
> at
>
> org.apache.sling.servlets.get.impl.JsonQueryServlet.dumpResult(JsonQueryServ
> let.java:193)
> at
>
> org.apache.sling.servlets.get.impl.JsonQueryServlet.doGet(JsonQueryServlet.j
> ava:106)
> at
>
> org.apache.sling.api.servlets.SlingSafeMethodsServlet.mayService(SlingSafeMe
> thodsServlet.java:268)
> at
>
> org.apache.sling.api.servlets.SlingSafeMethodsServlet.service(SlingSafeMetho
> dsServlet.java:344)
> at
>
> org.apache.sling.api.servlets.SlingSafeMethodsServlet.service(SlingSafeMetho
> dsServlet.java:375)
> at
>
> org.apache.sling.engine.impl.request.RequestData.service(RequestData.java:52
> 9)
> at
>
> org.apache.sling.engine.impl.SlingRequestProcessorImpl.processComponent(Slin
> gRequestProcessorImpl.java:274)
> at
>
> org.apache.sling.engine.impl.filter.RequestSlingFilterChain.render(RequestSl
> ingFilterChain.java:49)
> at
>
> org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(Abstra
> ctSlingFilterChain.java:64)
> at
>
> org.apache.sling.engine.impl.debug.RequestProgressTrackerLogFilter.doFilter(
> RequestProgressTrackerLogFilter.java:59)
> at
>
> org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(Abstra
> ctSlingFilterChain.java:60)
> at
>
> org.apache.sling.engine.impl.SlingRequestProcessorImpl.processRequest(SlingR
> equestProcessorImpl.java:161)
> at
>
> org.apache.sling.engine.impl.SlingMainServlet.service(SlingMainServlet.java:
> 183)
> at
>
> org.apache.felix.http.base.internal.handler.ServletHandler.doHandle(ServletH
> andler.java:96)
> at
>
> org.apache.felix.http.base.internal.handler.ServletHandler.handle(ServletHan
> dler.java:79)
> at
>
> org.apache.felix.http.base.internal.dispatch.ServletPipeline.handle(ServletP
> ipeline.java:42)
> at
>
> org.apache.felix.http.base.internal.dispatch.InvocationFilterChain.doFilter(
> InvocationFilterChain.java:49)
> at
>
> org.apache.felix.http.base.internal.dispatch.HttpFilterChain.doFilter(HttpFi
> lterChain.java:33)
> at
>
> org.apache.felix.http.base.internal.dispatch.FilterPipeline.dispatch(FilterP
> ipeline.java:48)
> at
>
> org.apache.felix.http.base.internal.dispatch.Dispatcher.dispatch(Dispatcher.
> java:39)
> at
>
> org.apache.felix.http.base.internal.DispatcherServlet.service(DispatcherServ
> let.java:67)
> at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
> at
> org.apache.felix.http.proxy.ProxyServlet.service(ProxyServlet.java:60)
> at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
> at
>
> org.apache.sling.launchpad.base.webapp.SlingServletDelegate.service(SlingSer
> vletDelegate.java:277)
> at
>
> org.apache.sling.launchpad.webapp.SlingServlet.service(SlingServlet.java:148
> )
> at
>
> weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSe
> curityHelper.java:227)
> at
>
> weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelpe
> r.java:125)
> at
> weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:292)
> at
> weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:175)
> at
>
> weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(W
> ebAppServletContext.java:3498)
> at
>
> weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubjec
> t.java:321)
> at weblogic.security.service.SecurityManager.runAs(Unknown Source)
> at
>
> weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletC
> ontext.java:2180)
> at
>
> weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.
> java:2086)
> at
>
> weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:140
> 6)
> at weblogic.work.ExecuteThread.execute(ExecuteThread.java:201)
> at weblogic.work.ExecuteThread.run(ExecuteThread.java:173)
>
>
>
>