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Posted to dev@abdera.apache.org by joe kim <jo...@gmail.com> on 2006/06/28 03:52:33 UTC
Getting started with Abdera
I setup an eclipse workspace and checked out the abdera code from SVN.
I had some trouble running the example class
org.apache.abdera.examples.simple.Parse. I made sure that the String
passed to getResourceAsStream() was a valid path to "simple.xml". Here
is the error I had:
Exception in thread "main" org.apache.abdera.parser.ParseException:
java.lang.NullPointerException
at org.apache.abdera.parser.stax.FOMParser.parse(FOMParser.java:74)
at org.apache.abdera.util.AbstractParser.parse(AbstractParser.java:41)
at org.apache.abdera.examples.simple.Parse.main(Parse.java:33)
Caused by: java.lang.NullPointerException
at com.ctc.wstx.io.StreamBootstrapper.initialLoad(StreamBootstrapper.java:457)
at com.ctc.wstx.io.StreamBootstrapper.resolveStreamEncoding(StreamBootstrapper.java:217)
at com.ctc.wstx.io.StreamBootstrapper.bootstrapInput(StreamBootstrapper.java:103)
at com.ctc.wstx.stax.WstxInputFactory.createSR(WstxInputFactory.java:533)
at com.ctc.wstx.stax.WstxInputFactory.createSR(WstxInputFactory.java:521)
at com.ctc.wstx.stax.WstxInputFactory.createXMLStreamReader(WstxInputFactory.java:266)
at org.apache.axiom.om.util.StAXUtils.createXMLStreamReader(StAXUtils.java:61)
at org.apache.axiom.om.impl.builder.StAXOMBuilder.<init>(StAXOMBuilder.java:96)
at org.apache.abdera.parser.stax.FOMBuilder.<init>(FOMBuilder.java:116)
at org.apache.abdera.parser.stax.FOMParser.parse(FOMParser.java:70)
... 2 more
Any thoughts? Are there plans to use other parsers such as JDOM?
Joe
Re: Getting started with Abdera
Posted by James M Snell <ja...@gmail.com>.
I'm giving some thought to this as we need something along these lines
for JSON/RDF conversions. I'll see if I can post some additional
information in the coming few days.
- James
Garrett Rooney wrote:
> On 6/28/06, joe kim <jo...@gmail.com> wrote:
>
>> You are right, I got it wrong. But, what is the advantage of only
>> pulling files from the classpath?
>
> The advantage is that the example is self contained ;-)
>
>> > Yep, although the barrier is a bit high. The FOM* impl classes are
>> > dependent on the Axiom implementation. So you either implement JDOM as
>> > a layer under Axiom or create a JDOM-based impl of the FOM* classes.
>>
>> Sounds quite involved. Are there no Atom model pojo's that can just
>> be populated with data by some arbitrary code?
>
> Currently, not that I'm aware of, at least not in Abdera's codebase.
>
> -garrett
>
Re: Getting started with Abdera
Posted by Garrett Rooney <ro...@electricjellyfish.net>.
On 6/28/06, joe kim <jo...@gmail.com> wrote:
> You are right, I got it wrong. But, what is the advantage of only
> pulling files from the classpath?
The advantage is that the example is self contained ;-)
> > Yep, although the barrier is a bit high. The FOM* impl classes are
> > dependent on the Axiom implementation. So you either implement JDOM as
> > a layer under Axiom or create a JDOM-based impl of the FOM* classes.
>
> Sounds quite involved. Are there no Atom model pojo's that can just
> be populated with data by some arbitrary code?
Currently, not that I'm aware of, at least not in Abdera's codebase.
-garrett
Re: Getting started with Abdera
Posted by joe kim <jo...@gmail.com>.
> Yep. I've seen this on several occasions and it always happens on a null
> stream. We need to add some error checking on that
I saw the patched. That's quick.
> > InputStream in =
> > Parse.class.getResourceAsStream("/home/rooneg/.../simple.xml");
> >
> > If so, that's incorrect, getResourceAsStream tries to pull a file out
> > of the classpath, so you need to make sure a directory containing that
> > file (i.e. the resources directory, or someplace the contents of that
> > directory are copied) is in the classpath when you run the test.
You are right, I got it wrong. But, what is the advantage of only
pulling files from the classpath?
> Yep, although the barrier is a bit high. The FOM* impl classes are
> dependent on the Axiom implementation. So you either implement JDOM as
> a layer under Axiom or create a JDOM-based impl of the FOM* classes.
Sounds quite involved. Are there no Atom model pojo's that can just
be populated with data by some arbitrary code?
Joe
Re: Getting started with Abdera
Posted by James M Snell <ja...@gmail.com>.
Garrett Rooney wrote:
>[snip]
> That kind of error tends to result from passing a null stream to
> parse(). When you say that the path to simple.xml was "valid", do you
> mean you gave it a full system path, like:
>
Yep. I've seen this on several occasions and it always happens on a null
stream. We need to add some error checking on that
> InputStream in =
> Parse.class.getResourceAsStream("/home/rooneg/.../simple.xml");
>
> If so, that's incorrect, getResourceAsStream tries to pull a file out
> of the classpath, so you need to make sure a directory containing that
> file (i.e. the resources directory, or someplace the contents of that
> directory are copied) is in the classpath when you run the test.
>
>> Any thoughts? Are there plans to use other parsers such as JDOM?
>
> I don't know, do you plan to write a parser that uses JDOM? ;-)
>
> Seriously, as I understand it, Abdera is written in such a way as to
> allow multiple parser back ends, so the only limitation is the lack of
> volunteers to write parser back ends for whatever kind of XML parser
> is desired.
>
Yep, although the barrier is a bit high. The FOM* impl classes are
dependent on the Axiom implementation. So you either implement JDOM as
a layer under Axiom or create a JDOM-based impl of the FOM* classes.
> -garrett
>
Re: Getting started with Abdera
Posted by Garrett Rooney <ro...@electricjellyfish.net>.
On 6/27/06, joe kim <jo...@gmail.com> wrote:
> I setup an eclipse workspace and checked out the abdera code from SVN.
>
> I had some trouble running the example class
> org.apache.abdera.examples.simple.Parse. I made sure that the String
> passed to getResourceAsStream() was a valid path to "simple.xml". Here
> is the error I had:
>
> Exception in thread "main" org.apache.abdera.parser.ParseException:
> java.lang.NullPointerException
> at org.apache.abdera.parser.stax.FOMParser.parse(FOMParser.java:74)
> at org.apache.abdera.util.AbstractParser.parse(AbstractParser.java:41)
> at org.apache.abdera.examples.simple.Parse.main(Parse.java:33)
> Caused by: java.lang.NullPointerException
> at com.ctc.wstx.io.StreamBootstrapper.initialLoad(StreamBootstrapper.java:457)
> at com.ctc.wstx.io.StreamBootstrapper.resolveStreamEncoding(StreamBootstrapper.java:217)
> at com.ctc.wstx.io.StreamBootstrapper.bootstrapInput(StreamBootstrapper.java:103)
> at com.ctc.wstx.stax.WstxInputFactory.createSR(WstxInputFactory.java:533)
> at com.ctc.wstx.stax.WstxInputFactory.createSR(WstxInputFactory.java:521)
> at com.ctc.wstx.stax.WstxInputFactory.createXMLStreamReader(WstxInputFactory.java:266)
> at org.apache.axiom.om.util.StAXUtils.createXMLStreamReader(StAXUtils.java:61)
> at org.apache.axiom.om.impl.builder.StAXOMBuilder.<init>(StAXOMBuilder.java:96)
> at org.apache.abdera.parser.stax.FOMBuilder.<init>(FOMBuilder.java:116)
> at org.apache.abdera.parser.stax.FOMParser.parse(FOMParser.java:70)
> ... 2 more
That kind of error tends to result from passing a null stream to
parse(). When you say that the path to simple.xml was "valid", do you
mean you gave it a full system path, like:
InputStream in = Parse.class.getResourceAsStream("/home/rooneg/.../simple.xml");
If so, that's incorrect, getResourceAsStream tries to pull a file out
of the classpath, so you need to make sure a directory containing that
file (i.e. the resources directory, or someplace the contents of that
directory are copied) is in the classpath when you run the test.
> Any thoughts? Are there plans to use other parsers such as JDOM?
I don't know, do you plan to write a parser that uses JDOM? ;-)
Seriously, as I understand it, Abdera is written in such a way as to
allow multiple parser back ends, so the only limitation is the lack of
volunteers to write parser back ends for whatever kind of XML parser
is desired.
-garrett