For efficiency reasons I can see why you are using String[] here and not
List.add()...
Anyway, I have a fix (sort of) for this bug. The number of names needs to be
calculated a little differently to what it currently is...
public String[] getPropertyNames() {
/* @todo do something about the sorting - LIKE WHAT? - MJB */
if (names == null) {
DynaClass dynaClass = dynaBean.getDynaClass();
DynaProperty[] properties = dynaClass.getDynaProperties();
int count = properties.length;
boolean hasClass = dynaClass.getDynaProperty("class") != null;
//count the number of property names we have
count = 0;
for (int i = 0; i < properties.length; i++) {
String name = properties[i].getName();
if (!hasClass || !name.equals("class")) {
count++; //it's only a property is it's not a class and
doesn't just have a class property.
}
}
//read the property names into a String[] to return
names = new String[count];
for (int i = 0, j = 0; i < properties.length; i++) {
String name = properties[i].getName();
if (!hasClass || !name.equals("class")) {
names[j++] = name;
}
}
Arrays.sort(names);
}
return names;
}
Now I can sort of sucessfully run all my expressions, yippee!! However, I
now have a problem with multiple deep results. Queries like //dog/* I would
expect to return all "dog's"[] but this just returns the first one it finds.
Maybe this is asking a little too much of JXPath and child/node
step-up/step-down traversal? Matt can probably tell me if this is or is not
the case pleeeease :)
On Wed, Mar 4, 2009 at 9:38 AM, Andrew Hughes <ahhug...@gmail.com> wrote:
> Pretty sure this is a bug in JXPath - and it is not tested by the current
> unit tests.
> I can't quite work out 100% of what's going on here... but it has to do
> with gathering the property names from a DynaBean child member of a (parent)
> DynaBean. Especially, when it try's to deal with the property named 'name'
> and 'class'.
>
> The problem with query '//dog' etc's 'ArrayOutOfBoundsException 0' occurs
> below. And rightfully so, names[] is a zero length array and for some
> reason JXPath is trying to set a value for the first entry of a zero length
> array. That aint ever going to work! But why is the array length zero?
> Because the properties.length==1, however the 'hasClass==true' and it's
> count-- then negates the correct count calculated from properties.length. I
> think the problem is in the hasClass calculation... 'boolean hasClass =
> dynaClass.getDynaProperty("class") != null;' or the conditional 'if'
> statement. I don't understand the JXPath logic here completely, but I know
> it doesn't deal with the way I am using it and I genuinely feel this is a
> bug we can fix :'(
>
>
> public String[] getPropertyNames() {
> /* @todo do something about the sorting - LIKE WHAT? - MJB */
> if (names == null) {
> DynaClass dynaClass = dynaBean.getDynaClass();
> DynaProperty[] properties = dynaClass.getDynaProperties();
> //returns one property 'name=root' (correct)
> int count = properties.length; //returns/set's '1' (correct)
> boolean hasClass = dynaClass.getDynaProperty("class") != null;
> //returns/sets 'true' (?unknown?)
> if (hasClass) { //this is true and executes
> count--; // Exclude "class" from properties
> }
> names = new String[count]; //names is a zero length array.....
> WRONG!!! I do have at least 1 property called 'name'!!!!
> for (int i = 0, j = 0; i < properties.length; i++) {
> String name = properties[i].getName();
> if (!hasClass || !name.equals("class")) {
> names[j++] = name; //it breaks here
> ArrayOutOfBoundsException 0!!!!! WRONG :'(
> }
> }
> Arrays.sort(names);
> }
> return names;
> }
>
>
>
>
> On Fri, Feb 27, 2009 at 10:02 AM, Andrew Hughes <ahhug...@gmail.com>wrote:
>
>> Thanks again Matt, good to hear that it's working at your end :) At my end
>> JXPath's DynaBeanPropertyPointer seems to get into problems
>> with ArraIndexOutOfBounds exceptions on the PropertyNames of my DynaBean (see
>> the strack trace below) with many of the queries. I can only speculate
>> why this might be... and I won't speculate publically. I'm running the code
>> with JXPath 1.3, BeanUtils 1.8.0, and Java 1.6_u11 (within eclipse 3.4). The
>> code I'm trying to run is pasted below VERBATIM.... if that works on your
>> environment and not mine then it must be a compatibility/platform problem.
>> You've helped me out heaps so far Matt but can I please ask you to
>> copy/paste the VERBATIM code and test?
>>
>> 2009-02-27 08:43:59,940 ERROR (Main.java:89) [runEvaluation] Failed to
>> evaluate /root/animal/cat/tiger[last()]
>>
>> java.lang.ArrayIndexOutOfBoundsException: 0
>>
>> at
>> org.apache.commons.jxpath.ri.model.dynabeans.DynaBeanPropertyPointer.getPropertyNames(DynaBeanPropertyPointer.java:84)
>>
>> at
>> org.apache.commons.jxpath.ri.model.beans.PropertyIterator.prepareForIndividualProperty(PropertyIterator.java:270)
>>
>> at
>> org.apache.commons.jxpath.ri.model.beans.PropertyIterator.setPositionIndividualProperty(PropertyIterator.java:154)
>>
>> at
>> org.apache.commons.jxpath.ri.model.beans.PropertyIterator.setPosition(PropertyIterator.java:139)
>>
>> at
>> org.apache.commons.jxpath.ri.axes.ChildContext.setPosition(ChildContext.java:101)
>>
>> at
>> org.apache.commons.jxpath.ri.axes.ChildContext.nextNode(ChildContext.java:87)
>>
>> at
>> org.apache.commons.jxpath.ri.EvalContext.nextSet(EvalContext.java:340)
>>
>> at
>> org.apache.commons.jxpath.ri.EvalContext.nextSet(EvalContext.java:339)
>>
>> at
>> org.apache.commons.jxpath.ri.EvalContext.nextSet(EvalContext.java:339)
>>
>> at
>> org.apache.commons.jxpath.ri.axes.PredicateContext.nextSet(PredicateContext.java:174)
>>
>> at
>> org.apache.commons.jxpath.ri.EvalContext.getSingleNodePointer(EvalContext.java:311)
>>
>> at
>> org.apache.commons.jxpath.ri.compiler.Path.searchForPath(Path.java:201)
>>
>> at
>> org.apache.commons.jxpath.ri.compiler.Path.getSingleNodePointerForSteps(Path.java:176)
>>
>> at
>> org.apache.commons.jxpath.ri.compiler.LocationPath.computeValue(LocationPath.java:87)
>>
>> at
>> org.apache.commons.jxpath.ri.JXPathContextReferenceImpl.getValue(JXPathContextReferenceImpl.java:353)
>>
>> at
>> org.apache.commons.jxpath.ri.JXPathContextReferenceImpl.getValue(JXPathContextReferenceImpl.java:313)
>>
>> at rnd.Main.runEvaluation(Main.java:68)
>>
>> at rnd.Main.main(Main.java:56)
>>
>> 2009-02-27 08:43:59,956 INFO (Main.java:66) [runEvaluation] About to
>> evaulate the expression: /root/animal/dog/*
>>
>> 2009-02-27 08:43:59,956 ERROR (Main.java:89) [runEvaluation] Failed to
>> evaluate /root/animal/dog/*
>>
>> java.lang.ArrayIndexOutOfBoundsException: 0
>>
>> at
>> org.apache.commons.jxpath.ri.model.dynabeans.DynaBeanPropertyPointer.getPropertyNames(DynaBeanPropertyPointer.java:84)
>>
>> at
>> org.apache.commons.jxpath.ri.model.beans.PropertyIterator.prepareForIndividualProperty(PropertyIterator.java:270)
>>
>> at
>> org.apache.commons.jxpath.ri.model.beans.PropertyIterator.setPositionIndividualProperty(PropertyIterator.java:154)
>>
>> at
>> org.apache.commons.jxpath.ri.model.beans.PropertyIterator.setPosition(PropertyIterator.java:139)
>>
>> at
>> org.apache.commons.jxpath.ri.axes.ChildContext.setPosition(ChildContext.java:101)
>>
>> at
>> org.apache.commons.jxpath.ri.axes.ChildContext.nextNode(ChildContext.java:87)
>>
>> at
>> org.apache.commons.jxpath.ri.EvalContext.nextSet(EvalContext.java:340)
>>
>> at
>> org.apache.commons.jxpath.ri.EvalContext.nextSet(EvalContext.java:339)
>>
>> at
>> org.apache.commons.jxpath.ri.EvalContext.nextSet(EvalContext.java:339)
>>
>> at
>> org.apache.commons.jxpath.ri.axes.ChildContext.getSingleNodePointer(ChildContext.java:70)
>>
>> at
>> org.apache.commons.jxpath.ri.compiler.Path.searchForPath(Path.java:201)
>>
>> at
>> org.apache.commons.jxpath.ri.compiler.Path.getSingleNodePointerForSteps(Path.java:176)
>>
>> at
>> org.apache.commons.jxpath.ri.compiler.LocationPath.computeValue(LocationPath.java:87)
>>
>> at
>> org.apache.commons.jxpath.ri.JXPathContextReferenceImpl.getValue(JXPathContextReferenceImpl.java:353)
>>
>> at
>> org.apache.commons.jxpath.ri.JXPathContextReferenceImpl.getValue(JXPathContextReferenceImpl.java:313)
>>
>> at rnd.Main.runEvaluation(Main.java:68)
>>
>> at rnd.Main.main(Main.java:57)
>>
>> 2009-02-27 08:43:59,956 INFO (Main.java:66) [runEvaluation] About to
>> evaulate the expression: //dog
>>
>> 2009-02-27 08:43:59,956 ERROR (Main.java:89) [runEvaluation] Failed to
>> evaluate //dog
>>
>> java.lang.ArrayIndexOutOfBoundsException: 0
>>
>> at
>> org.apache.commons.jxpath.ri.model.dynabeans.DynaBeanPropertyPointer.getPropertyNames(DynaBeanPropertyPointer.java:84)
>>
>> at
>> org.apache.commons.jxpath.ri.model.beans.PropertyIterator.prepareForIndividualProperty(PropertyIterator.java:270)
>>
>> at
>> org.apache.commons.jxpath.ri.model.beans.PropertyIterator.getNodePointer(PropertyIterator.java:106)
>>
>> at
>> org.apache.commons.jxpath.ri.axes.ChildContext.getSingleNodePointer(ChildContext.java:76)
>>
>> at
>> org.apache.commons.jxpath.ri.compiler.Path.searchForPath(Path.java:201)
>>
>> at
>> org.apache.commons.jxpath.ri.compiler.Path.getSingleNodePointerForSteps(Path.java:176)
>>
>> at
>> org.apache.commons.jxpath.ri.compiler.LocationPath.computeValue(LocationPath.java:87)
>>
>> at
>> org.apache.commons.jxpath.ri.JXPathContextReferenceImpl.getValue(JXPathContextReferenceImpl.java:353)
>>
>> at
>> org.apache.commons.jxpath.ri.JXPathContextReferenceImpl.getValue(JXPathContextReferenceImpl.java:313)
>>
>> at rnd.Main.runEvaluation(Main.java:68)
>>
>> at rnd.Main.main(Main.java:58)
>>
>> 2009-02-27 08:43:59,956 INFO (Main.java:66) [runEvaluation] About to
>> evaulate the expression: //dog/*
>>
>> 2009-02-27 08:43:59,956 ERROR (Main.java:89) [runEvaluation] Failed to
>> evaluate //dog/*
>>
>> java.lang.ArrayIndexOutOfBoundsException: 0
>>
>> at
>> org.apache.commons.jxpath.ri.model.dynabeans.DynaBeanPropertyPointer.getPropertyNames(DynaBeanPropertyPointer.java:84)
>>
>> at
>> org.apache.commons.jxpath.ri.model.beans.PropertyIterator.prepareForIndividualProperty(PropertyIterator.java:270)
>>
>> at
>> org.apache.commons.jxpath.ri.model.beans.PropertyIterator.setPositionIndividualProperty(PropertyIterator.java:154)
>>
>> at
>> org.apache.commons.jxpath.ri.model.beans.PropertyIterator.setPosition(PropertyIterator.java:139)
>>
>> at
>> org.apache.commons.jxpath.ri.axes.ChildContext.setPosition(ChildContext.java:101)
>>
>> at
>> org.apache.commons.jxpath.ri.axes.ChildContext.nextNode(ChildContext.java:87)
>>
>> at
>> org.apache.commons.jxpath.ri.EvalContext.nextSet(EvalContext.java:340)
>>
>> at
>> org.apache.commons.jxpath.ri.axes.ChildContext.getSingleNodePointer(ChildContext.java:70)
>>
>> at
>> org.apache.commons.jxpath.ri.compiler.Path.searchForPath(Path.java:201)
>>
>> at
>> org.apache.commons.jxpath.ri.compiler.Path.getSingleNodePointerForSteps(Path.java:176)
>>
>> at
>> org.apache.commons.jxpath.ri.compiler.LocationPath.computeValue(LocationPath.java:87)
>>
>> at
>> org.apache.commons.jxpath.ri.JXPathContextReferenceImpl.getValue(JXPathContextReferenceImpl.java:353)
>>
>> at
>> org.apache.commons.jxpath.ri.JXPathContextReferenceImpl.getValue(JXPathContextReferenceImpl.java:313)
>>
>> at rnd.Main.runEvaluation(Main.java:68)
>>
>> at rnd.Main.main(Main.java:59)
>>
>> 2009-02-27 08:43:59,956 INFO (Main.java:66) [runEvaluation] About to
>> evaulate the expression: //cat/*[objectName='LION']
>>
>> 2009-02-27 08:43:59,956 ERROR (Main.java:89) [runEvaluation] Failed to
>> evaluate //cat/*[objectName='LION']
>>
>> java.lang.ArrayIndexOutOfBoundsException: 0
>>
>> at
>> org.apache.commons.jxpath.ri.model.dynabeans.DynaBeanPropertyPointer.getPropertyNames(DynaBeanPropertyPointer.java:84)
>>
>> at
>> org.apache.commons.jxpath.ri.model.beans.PropertyIterator.prepareForIndividualProperty(PropertyIterator.java:270)
>>
>> at
>> org.apache.commons.jxpath.ri.model.beans.PropertyIterator.setPositionIndividualProperty(PropertyIterator.java:154)
>>
>> at
>> org.apache.commons.jxpath.ri.model.beans.PropertyIterator.setPosition(PropertyIterator.java:139)
>>
>> at
>> org.apache.commons.jxpath.ri.axes.ChildContext.setPosition(ChildContext.java:101)
>>
>> at
>> org.apache.commons.jxpath.ri.axes.ChildContext.nextNode(ChildContext.java:87)
>>
>> at
>> org.apache.commons.jxpath.ri.EvalContext.nextSet(EvalContext.java:340)
>>
>> at
>> org.apache.commons.jxpath.ri.axes.PredicateContext.nextSet(PredicateContext.java:174)
>>
>> at
>> org.apache.commons.jxpath.ri.EvalContext.getSingleNodePointer(EvalContext.java:311)
>>
>> at
>> org.apache.commons.jxpath.ri.compiler.Path.searchForPath(Path.java:201)
>>
>> at
>> org.apache.commons.jxpath.ri.compiler.Path.getSingleNodePointerForSteps(Path.java:176)
>>
>> at
>> org.apache.commons.jxpath.ri.compiler.LocationPath.computeValue(LocationPath.java:87)
>>
>> at
>> org.apache.commons.jxpath.ri.JXPathContextReferenceImpl.getValue(JXPathContextReferenceImpl.java:353)
>>
>> at
>> org.apache.commons.jxpath.ri.JXPathContextReferenceImpl.getValue(JXPathContextReferenceImpl.java:313)
>>
>> at rnd.Main.runEvaluation(Main.java:68)
>>
>> at rnd.Main.main(Main.java:60)
>>
>>
>>
>>
>> My Code VERBATIM
>>
>> package rnd;
>>
>> import java.util.ArrayList;
>>
>> import org.apache.commons.beanutils.LazyDynaBean;
>> import org.apache.commons.jxpath.JXPathContext;
>> import org.apache.log4j.Logger;
>>
>> public class Main {
>>
>> private static final Logger log = Logger.getLogger(Main.class);
>>
>> public static void main(String[] args) {
>> log.info("Starting...");
>> LazyDynaBean lazyDynaBean = new LazyDynaBean(); //the transparent root.
>> LazyDynaBean root = new LazyDynaBean();
>> LazyDynaBean animal = new LazyDynaBean();
>> LazyDynaBean dog = new LazyDynaBean();
>> LazyDynaBean cat = new LazyDynaBean();
>> LazyDynaBean boxer = new LazyDynaBean();
>> LazyDynaBean labrador = new LazyDynaBean();
>> LazyDynaBean tiger1 = new LazyDynaBean();
>> LazyDynaBean tiger2 = new LazyDynaBean();
>> LazyDynaBean tiger3 = new LazyDynaBean();
>> LazyDynaBean lion = new LazyDynaBean();
>> //set the @objectName property of each bean, user UPPER to make them
>> distinct for examples.
>> root.set("objectName","ROOT");
>> animal.set("objectName","ANIMAL");
>> dog.set("objectName","DOG");
>> cat.set("objectName","CAT");
>> boxer.set("objectName","BOXER");
>> labrador.set("objectName","LABRADOR");
>> tiger1.set("objectName","TIGER-ONE");
>> tiger2.set("objectName","TIGER-TWO");
>> tiger3.set("objectName","TIGER-THREE");
>> lion.set("objectName","LION");
>> //build the bean hierarchy.
>> lazyDynaBean.set("root",0, root);
>> root.set("animal",0, animal);
>> animal.set("dog",0,dog);
>> animal.set("cat",0,cat);
>> dog.set("labrador",0,labrador);
>> dog.set("boxer",0, boxer);
>> cat.set("tiger",0,tiger1);//duplicate
>> cat.set("tiger",1,tiger2);//duplicate
>> cat.set("tiger",2,tiger3);//duplicate
>> cat.set("lion",0,lion);
>>
>> JXPathContext context = JXPathContext.newContext(lazyDynaBean);
>>
>> //these all work
>> runEvaluation("/root/animal/dog", context); //absolute & single
>> runEvaluation("/root/animal/cat/tiger[2]", context); //absolute &
>> single
>> runEvaluation("/root/animal/cat/tiger", context); //absolute &
>> multiple
>> //everything below fails
>> runEvaluation("/root/animal/cat/tiger[last()]", context);
>> //absolute & single
>> runEvaluation("/root/animal/dog/*", context); //absolute &
>> multiple
>> runEvaluation("//dog", context); //deep search
>> runEvaluation("//dog/*", context);//deep multiple
>> runEvaluation("//cat/*[objectName='LION']", context);//deep filter
>>
>> }
>>
>>
>> public static void runEvaluation(String expression,JXPathContext
>> context){
>> log.info("About to evaulate the expression: "+expression);
>> try {
>> Object value = context.getValue(expression);
>> //we got a single result.
>> if (value instanceof LazyDynaBean) {
>> LazyDynaBean r = (LazyDynaBean)context.getValue(expression);
>> log.info("Ran '" + expression + "' and got objectName='" +
>> r.get("objectName") + "'");
>>
>> }
>> //we got multiple results
>> else if (value instanceof ArrayList) {
>> String titles = "";
>> for (LazyDynaBean bean : ((ArrayList<LazyDynaBean>) value )){
>> titles += (bean.get("objectName")+",");
>> }
>> log.info("Ran " + expression + " and got "+((ArrayList)value).size()+"
>> results: "+titles);
>> }
>> //we got a non-dyna bean.
>> else {
>> log.info("Ran '" + expression + "' and got a class '" +
>> value.getClass().getName() + "' with toString() '" +value.toString() + "'");
>> }
>> } catch (Exception e) {
>> // TODO Auto-generated catch block
>> log.error("Failed to evaluate "+expression,e);
>> }
>> }
>> }
>>
>>
>>
>>
>> On Fri, Feb 27, 2009 at 3:56 AM, Matt Benson <gudnabr...@yahoo.com>wrote:
>>
>>>
>>> Those paths work for me. Maybe something else is going awry?
>>>
>>> -Matt
>>>
>>> --- On Thu, 2/26/09, Andrew Hughes <ahhug...@gmail.com> wrote:
>>>
>>> > From: Andrew Hughes <ahhug...@gmail.com>
>>> > Subject: Re: JXPath over Generic Collection<?>, How?
>>> > To: "Commons Users List" <user@commons.apache.org>
>>> > Date: Thursday, February 26, 2009, 12:53 AM
>>> > Many queries don't work, I
>>> > can't get any results for the following (code
>>> > taken from previous email)...
>>> >
>>> > runEvaluation("/root/animal/cat/tiger[last()]", context);
>>> > //absolute
>>> > & single
>>> >
>>> > runEvaluation("/root/animal/dog/*", context); //absolute
>>> > & multiple
>>> > runEvaluation("//dog",
>>> > context); //deep search
>>> > runEvaluation("//dog/*",
>>> > context);//deep multiple
>>> >
>>> > runEvaluation("//cat/*[objectName='LION']", context);//deep
>>> > filter
>>> >
>>> > These are the really interesting benefits on xpath that I
>>> > would dearly like
>>> > to have.
>>> >
>>> > A Huge Thanks once again for your reply Matt!!! :)
>>> >
>>> >
>>> >
>>> > On Thu, Feb 26, 2009 at 10:55 AM, Matt Benson <gudnabr...@yahoo.com>
>>> > wrote:
>>> >
>>> > >
>>> > > How so? If you simply treat the name property as
>>> > an element rather than an
>>> > > attribute, you're done, no?
>>> > >
>>> > > -Matt
>>> > >
>>> > > --- On Wed, 2/25/09, Andrew Hughes <ahhug...@gmail.com>
>>> > wrote:
>>> > >
>>> > > > From: Andrew Hughes <ahhug...@gmail.com>
>>> > > > Subject: Re: JXPath over Generic
>>> > Collection<?>, How?
>>> > > > To: "Commons Users List" <user@commons.apache.org>
>>> > > > Date: Wednesday, February 25, 2009, 6:22 PM
>>> > > > Indeed Matt, you are correct and I do
>>> > > > apologize... but I must say I find
>>> > > > your emailed explanation much better. Kudos &
>>> > Thanks!
>>> > > > I'll (finally) get a chance to work on this
>>> > tomorrow, but I
>>> > > > think I am still
>>> > > > stuck :'(
>>> > > >
>>> > > >
>>> > > > Cheers for everything so far!!!!
>>> > > >
>>> > > >
>>> > > > On Tue, Feb 24, 2009 at 1:43 PM, Matt Benson
>>> > <gudnabr...@yahoo.com>
>>> > > > wrote:
>>> > > >
>>> > > > >
>>> > > > > I won't get to look at this again at least
>>> > before
>>> > > > tomorrow (9PM for me now
>>> > > > > and still have some late-night $work to look
>>> > at), but
>>> > > > I thought I would
>>> > > > > mention straight off that the @name feature
>>> > actually
>>> > > > IS mentioned in the
>>> > > > > userguide under the section about working
>>> > with
>>> > > > (java.util.)Maps. If you
>>> > > > > have a suggestion of where in the guide
>>> > would be
>>> > > > another good place to
>>> > > > > mention it as a caveat and/or even the
>>> > wording to use,
>>> > > > feel free to open a
>>> > > > > documentation issue in JIRA for it.
>>> > > > >
>>> > > > > TBC,
>>> > > > > Matt
>>> > > > >
>>> > > > > --- On Mon, 2/23/09, Andrew Hughes <ahhug...@gmail.com>
>>> > > > wrote:
>>> > > > >
>>> > > > > > From: Andrew Hughes <ahhug...@gmail.com>
>>> > > > > > Subject: Re: JXPath over Generic
>>> > > > Collection<?>, How?
>>> > > > > > To: "Commons Users List" <user@commons.apache.org>
>>> > > > > > Date: Monday, February 23, 2009, 6:24
>>> > PM
>>> > > > > > Hi Matt,
>>> > > > > > Thanks HEAPS for you reply, I am really
>>> > really
>>> > > > really
>>> > > > > > grateful. I think that
>>> > > > > > I have progressed just a little with
>>> > this but
>>> > > > there are
>>> > > > > > still some BIG
>>> > > > > > shortfalls with this. I've attached
>>> > code that
>>> > > > should run
>>> > > > > > out the box and is
>>> > > > > > based on previous emails. If I can get
>>> > the
>>> > > > expressions
>>> > > > > > below to correctly
>>> > > > > > evaluate I would be heaps happy.
>>> > > > > >
>>> > > > > > Thanks heaps again, hopefully this will
>>> > work soon
>>> > > > enough.
>>> > > > > >
>>> > > > > > p.s. I can understand the 'name' vs
>>> > '@name',
>>> > > > perhaps the
>>> > > > > > userguide could
>>> > > > > > mention this is about all I can add.
>>> > > > > >
>>> > > > > >
>>> > > > > > code...
>>> > > > > >
>>> > > > > > package rnd;
>>> > > > > >
>>> > > > > > import java.util.ArrayList;
>>> > > > > >
>>> > > > > > import
>>> > > > org.apache.commons.beanutils.LazyDynaBean;
>>> > > > > > import
>>> > org.apache.commons.jxpath.JXPathContext;
>>> > > > > > import org.apache.log4j.Logger;
>>> > > > > >
>>> > > > > > public class Main {
>>> > > > > >
>>> > > > > > private static final Logger log =
>>> > > > > > Logger.getLogger(Main.class);
>>> > > > > >
>>> > > > > > public static void main(String[] args)
>>> > {
>>> > > > > > log.info("Starting...");
>>> > > > > > LazyDynaBean lazyDynaBean = new
>>> > LazyDynaBean();
>>> > > > //the
>>> > > > > > transparent root.
>>> > > > > > LazyDynaBean root = new
>>> > LazyDynaBean();
>>> > > > > > LazyDynaBean animal = new
>>> > LazyDynaBean();
>>> > > > > > LazyDynaBean dog = new LazyDynaBean();
>>> > > > > > LazyDynaBean cat = new LazyDynaBean();
>>> > > > > > LazyDynaBean boxer = new
>>> > LazyDynaBean();
>>> > > > > > LazyDynaBean labrador = new
>>> > LazyDynaBean();
>>> > > > > > LazyDynaBean tiger1 = new
>>> > LazyDynaBean();
>>> > > > > > LazyDynaBean tiger2 = new
>>> > LazyDynaBean();
>>> > > > > > LazyDynaBean tiger3 = new
>>> > LazyDynaBean();
>>> > > > > > LazyDynaBean lion = new
>>> > LazyDynaBean();
>>> > > > > > //set the @objectName property of each
>>> > bean, user
>>> > > > UPPER to
>>> > > > > > make them
>>> > > > > > distinct for examples.
>>> > > > > > root.set("objectName","ROOT");
>>> > > > > > animal.set("objectName","ANIMAL");
>>> > > > > > dog.set("objectName","DOG");
>>> > > > > > cat.set("objectName","CAT");
>>> > > > > > boxer.set("objectName","BOXER");
>>> > > > > > labrador.set("objectName","LABRADOR");
>>> > > > > > tiger1.set("objectName","TIGER-ONE");
>>> > > > > > tiger2.set("objectName","TIGER-TWO");
>>> > > > > >
>>> > tiger3.set("objectName","TIGER-THREE");
>>> > > > > > lion.set("objectName","LION");
>>> > > > > > //build the bean hierarchy.
>>> > > > > > lazyDynaBean.set("root",0, root);
>>> > > > > > root.set("animal",0, animal);
>>> > > > > > animal.set("dog",0,dog);
>>> > > > > > animal.set("cat",0,cat);
>>> > > > > > dog.set("labrador",0,labrador);
>>> > > > > > dog.set("boxer",0, boxer);
>>> > > > > > cat.set("tiger",0,tiger1);//duplicate
>>> > > > > > cat.set("tiger",1,tiger2);//duplicate
>>> > > > > > cat.set("tiger",2,tiger3);//duplicate
>>> > > > > > cat.set("lion",0,lion);
>>> > > > > >
>>> > > > JXPathContext context =
>>> > > > > >
>>> > JXPathContext.newContext(lazyDynaBean);
>>> > > > > >
>>> > > > > >
>>> > //these all
>>> > > > work
>>> > > > > >
>>> > > > > > runEvaluation("/root/animal/dog",
>>> > context);
>>> > > > //absolute &
>>> > > > > > single
>>> > > > > >
>>> > > > > >
>>> > runEvaluation("/root/animal/cat/tiger[2]",
>>> > > > context);
>>> > > > > > //absolute &
>>> > > > > > single
>>> > > > > >
>>> > > > > > runEvaluation("/root/animal/cat/tiger",
>>> > context);
>>> > > > //absolute
>>> > > > > > &
>>> > > > > > multiple
>>> > > > > >
>>> > > > //everything below fails
>>> > > > > >
>>> > > > > >
>>> > runEvaluation("/root/animal/cat/tiger[last()]",
>>> > > > context);
>>> > > > > > //absolute
>>> > > > > > & single
>>> > > > > >
>>> > > > > > runEvaluation("/root/animal/dog/*",
>>> > context);
>>> > > > //absolute
>>> > > > > > & multiple
>>> > > > > >
>>> > > > runEvaluation("//dog",
>>> > > > > > context); //deep search
>>> > > > > >
>>> > > > runEvaluation("//dog/*",
>>> > > > > > context);//deep multiple
>>> > > > > >
>>> > > > > >
>>> > runEvaluation("//cat/*[objectName='LION']",
>>> > > > context);//deep
>>> > > > > > filter
>>> > > > > >
>>> > > > > > }
>>> > > > > > public static void
>>> > runEvaluation(String
>>> > > > > > expression,JXPathContext context){
>>> > > > > > log.info("About to evaulate the
>>> > expression:
>>> > > > "+expression);
>>> > > > > >
>>> > try {
>>> > > > > > Object value =
>>> > context.getValue(expression);
>>> > > > > > //we got a single result.
>>> > > > > > if (value instanceof LazyDynaBean) {
>>> > > > > > LazyDynaBean r =
>>> > > > > >
>>> > (LazyDynaBean)context.getValue(expression);
>>> > > > > > log.info("Ran '" + expression + "' and
>>> > got
>>> > > > objectName='" +
>>> > > > > > r.get("objectName") + "'");
>>> > > > > > }
>>> > > > > > //we got multiple results
>>> > > > > > else if (value instanceof ArrayList) {
>>> > > > > > String titles = "";
>>> > > > > > for (LazyDynaBean bean :
>>> > > > ((ArrayList<LazyDynaBean>)
>>> > > > > > value )){
>>> > > > > > titles +=
>>> > (bean.get("objectName")+",");
>>> > > > > > }
>>> > > > > > log.info("Ran " + expression + " and
>>> > got
>>> > > > > > "+((ArrayList)value).size()+"
>>> > > > > > results: "+titles);
>>> > > > > > }
>>> > > > > > //we got a non-dyna bean.
>>> > > > > > else {
>>> > > > > > log.info("Ran '" + expression + "' and
>>> > got a
>>> > > > class '" +
>>> > > > > > value.getClass().getName() + "' with
>>> > toString()
>>> > > > '"
>>> > > > > > +value.toString() + "'");
>>> > > > > > }
>>> > > > > > } catch (Exception e) {
>>> > > > > > log.error(e);
>>> > > > > > }
>>> > > > > > }
>>> > > > > > }
>>> > > > > >
>>> > > > > >
>>> > > > > >
>>> > > > > >
>>> > > > > >
>>> > > > > > On Tue, Feb 24, 2009 at 8:58 AM, Matt
>>> > Benson
>>> > > > <gudnabr...@yahoo.com>
>>> > > > > > wrote:
>>> > > > > >
>>> > > > > > >
>>> > > > > > > And the answer is:
>>> > > > > > >
>>> > > > > > > In JXPath, a decision was
>>> > made to
>>> > > > overload the
>>> > > > > > name attribute to refer to
>>> > > > > > > an "element"'s property name WRT
>>> > its
>>> > > > parent. The
>>> > > > > > reason this was done was
>>> > > > > > > to support query maps with
>>> > non-String keys
>>> > > > in
>>> > > > > > JXPath. This means that
>>> > > > > > > anytime you actually want to refer
>>> > to a
>>> > > > property whose
>>> > > > > > name literally is
>>> > > > > > > "name", you must treat it as a
>>> > child element
>>> > > > rather
>>> > > > > > than an attribute. So
>>> > > > > > > in your case you could either
>>> > change "name"
>>> > > > to "title"
>>> > > > > > and query
>>> > > > > > > [...@title='foo'] or simply use
>>> > [name='foo'].
>>> > > > > > >
>>> > > > > > > Regards,
>>> > > > > > > Matt
>>> > > > > > >
>>> > > > > > > --- On Mon, 2/23/09, Matt Benson
>>> > <gudnabr...@yahoo.com>
>>> > > > > > wrote:
>>> > > > > > >
>>> > > > > > > > From: Matt Benson <gudnabr...@yahoo.com>
>>> > > > > > > > Subject: Re: JXPath over
>>> > Generic
>>> > > > > > Collection<?>, How?
>>> > > > > > > > To: "Commons Users List"
>>> > <user@commons.apache.org>
>>> > > > > > > > Date: Monday, February 23,
>>> > 2009, 2:58
>>> > > > PM
>>> > > > > > > >
>>> > > > > > > > To follow up, the 'name'
>>> > attribute in
>>> > > > particular
>>> > > > > > is what
>>> > > > > > > > doesn't seem to be working
>>> > here (change
>>> > > > it to
>>> > > > > > e.g. 'game'
>>> > > > > > > > and it works fine)... if you
>>> > could file
>>> > > > a bug it
>>> > > > > > would help
>>> > > > > > > > me remember as I don't have
>>> > time to do
>>> > > > it myself
>>> > > > > > right this
>>> > > > > > > > minute.
>>> > > > > > > >
>>> > > > > > > > -Matt
>>> > > > > > > >
>>> > > > > > > > --- On Mon, 2/23/09, Matt
>>> > Benson <gudnabr...@yahoo.com>
>>> > > > > > > > wrote:
>>> > > > > > > >
>>> > > > > > > > > From: Matt Benson <gudnabr...@yahoo.com>
>>> > > > > > > > > Subject: Re: JXPath over
>>> > Generic
>>> > > > > > Collection<?>,
>>> > > > > > > > How?
>>> > > > > > > > > To: "Commons Users List"
>>> > <user@commons.apache.org>
>>> > > > > > > > > Date: Monday, February
>>> > 23, 2009,
>>> > > > 12:27 PM
>>> > > > > > > > >
>>> > > > > > > > > Andrew,
>>> > > > > > > > > I've
>>> > been meaning
>>> > > > to look
>>> > > > > > into this but haven't
>>> > > > > > > > > yet. If you have
>>> > any
>>> > > > ready-to-run code
>>> > > > > > you can send
>>> > > > > > > > to
>>> > > > > > > > > the list, that wouldn't
>>> > hurt...
>>> > > > > > > > >
>>> > > > > > > > > -Matt
>>> > > > > > > > >
>>> > > > > > > > > --- On Mon, 2/23/09,
>>> > Andrew Hughes
>>> > > > <ahhug...@gmail.com>
>>> > > > > > > > > wrote:
>>> > > > > > > > >
>>> > > > > > > > > > From: Andrew Hughes
>>> > <ahhug...@gmail.com>
>>> > > > > > > > > > Subject: Re: JXPath
>>> > over
>>> > > > Generic
>>> > > > > > > > Collection<?>,
>>> > > > > > > > > How?
>>> > > > > > > > > > To: "Commons Users
>>> > List"
>>> > > > <user@commons.apache.org>
>>> > > > > > > > > > Date: Monday,
>>> > February 23,
>>> > > > 2009, 5:42
>>> > > > > > AM
>>> > > > > > > > > > OK, email #19 to
>>> > the list.
>>> > > > I'm both
>>> > > > > > > > > > incredibly patient
>>> > and
>>> > > > skeptical that
>>> > > > > > > > > > this will ever
>>> > work. I might
>>> > > > try and
>>> > > > > > run this in
>>> > > > > > > > a
>>> > > > > > > > > debugger
>>> > > > > > > > > > and track down
>>> > > > > > > > > > "how" JXPath
>>> > traverses the
>>> > > > DynaBean....
>>> > > > > > but given
>>> > > > > > > > the
>>> > > > > > > > > > reflection
>>> > involved
>>> > > > > > > > > > that might be a
>>> > painful
>>> > > > task.
>>> > > > > > > > > > --AH
>>> > > > > > > > > >
>>> > > > > > > > > >
>>> > > > > > > > > > On Tue, Feb 17,
>>> > 2009 at 1:11
>>> > > > PM, Andrew
>>> > > > > > Hughes
>>> > > > > > > > <ahhug...@gmail.com>
>>> > > > > > > > > > wrote:
>>> > > > > > > > > >
>>> > > > > > > > > > > Ping... if
>>> > anyone can
>>> > > > help with
>>> > > > > > this JXPath
>>> > > > > > > > > &
>>> > > > > > > > > > DynaBeans problem
>>> > I'd be
>>> > > > > > > > > > > REALLY
>>> > THANKFUL :)
>>> > > > > > > > > > >
>>> > > > > > > > > > >
>>> > > > > > > > > > > On Fri, Feb
>>> > 13, 2009 at
>>> > > > 1:55 PM,
>>> > > > > > Andrew
>>> > > > > > > > Hughes
>>> > > > > > > > > <ahhug...@gmail.com>
>>> > > > > > > > > > wrote:
>>> > > > > > > > > > >
>>> > > > > > > > > > >> Howdy,
>>> > > > > > > > > > >> I've taken
>>> > Matt's
>>> > > > suggestion
>>> > > > > > onboard and
>>> > > > > > > > I
>>> > > > > > > > > have
>>> > > > > > > > > > investigated
>>> > DynaBeans.
>>> > > > > > > > > > >> These look
>>> > pretty
>>> > > > good for
>>> > > > > > all
>>> > > > > > > > intestive
>>> > > > > > > > > purposes
>>> > > > > > > > > > and there's a code
>>> > > > > > > > > > >> examples
>>> > below how
>>> > > > to build
>>> > > > > > the data
>>> > > > > > > > > structure:
>>> > > > > > > > > > >>
>>> > > > > > > > > > >> + root
>>> > > > [...@name="ROOT"]
>>> > > > > > > > > > >>
>>> > > > +
>>> > > > > > animal [...@name="ANIMAL"]
>>> > > > > > > > > > >>
>>> > > > > > + dog
>>> > > > > > > > > > [...@name="DOG"]
>>> > > > > > > > > > >>
>>> > > > > > > > > > +
>>> > boxer
>>> > > > [...@name="BOXER"]
>>> > > > > > > > > > >>
>>> > > > > > > > > > +
>>> > labrador
>>> > > > > > [...@name="LABRADOR"]
>>> > > > > > > > > > >>
>>> > > > > > + cat
>>> > > > > > > > > > [...@name="CAT"]
>>> > > > > > > > > > >>
>>> > > > > > > > > > +
>>> > tiger
>>> > > > > > [...@name="TIGER-ONE"]
>>> > > > > > > > > > >>
>>> > > > > > > > > > +
>>> > tiger
>>> > > > > > [...@name="TIGER-TWO"]
>>> > > > > > > > > > >>
>>> > > > > > > > > > +
>>> > tiger
>>> > > > > > [...@name="TIGER-THREE"]
>>> > > > > > > > > > >>
>>> > > > > > > > > > +
>>> > lion
>>> > > > [...@name="LION"]
>>> > > > > > > > > > >>
>>> > > > > > > > > > >>
>>> > > > > > > > > > >> And the
>>> > code looks
>>> > > > like...
>>> > > > > > > > > > >>
>>> > > > > > > > > > >>
>>> > LazyDynaBean
>>> > > > > > lazyDynaBean = new
>>> > > > > > > > > > LazyDynaBean();
>>> > //the
>>> > > > transpar
>>>
>> ...
>>
>> [Message clipped]
>
>
>
