[jdom-interest] How to get nextSibling, prevSibling, firstChild and lastChild in JDOM?

[Harry Evans]

It is a bit more roundabout but:

//myElement is the <Element> element in your example
//List implementation:
Element parent = myElement.getParent();
List children = parent.getChildren();
int myIndex = children.indexOf(myElement);
//get prevSibling
if(myIndex > 0 && myIndex < children.size()) {
  Element prevElement = (Element)children.get(myIndex - 1);
}
//get nextSibling
if(myIndex >= 0 && myIndex < children.size() - 1) {
  Element nextElement = (Element)children.get(myIndex + 1);
}

//Iterator implementation
ListIterator iterator = myElement.getParent().getChildren().listIterator();
boolean done = false;
while(iterator.hasNext() && !done) {
  Element element = (Element)iterator.next();
  if(myElement.equals(element) {
    done = true;
  }
}
if(!done) {
  //error
} else {
  //get prevSibling
  if(iterator.hasPrevious()) {
    Element prevElement = (Element)iterator.previous();
    iterator.next(); //put it back on myElement
  }
  //get nextSibling
  if(iterator.hasNext()) {
    Element nextElement = (Element)iterator.next();
    iterator.previous(); //put it back on myElement
}

In my experience, usually getting next sibling and previous siblings is
done, at least in my experience, in the context of looking at all the
siblings, though your usage may vary.

Anyone else have a more elegant solution?

Harry

> -----Original Message-----
> From: Meghasyam Bokam [mailto:mbokam at cs.nmsu.edu]
> Sent: Tuesday, September 17, 2002 4:59 PM
> To: Harry Evans
> Subject: RE: [jdom-interest] How to get nextSibling, prevSibling,
> firstChild and lastChild in JDOM?
>
>
> Thank You Harry. I understood getting the first and last child of an
> element. But I will explain what I mean by siblings.
>
> <?xml version="1.0"?>
> <root>
>    <prevSibling>
>    	text
>    </prevSibling>
>    <Element>
> 	<child1> text </child1>
> 	<child2> text </child2>
>    </Element>
>    <nextSibling>
> 	text
>    </nextSibling>
> </root>
>
> Now if I am processing at "Element" , how to get the "nextSibling" and
> "prevSibling" elements, considering only I have "Element" at my hand.
>
> Thank You.
>
> Meghasyam.
>
>
> On Mon, 16 Sep 2002, Harry Evans wrote:
>
> > You can access the children of any element as a standard
> java.util.List by
> > just calling getChildren() on the Element.  Some examples
> of how you could
> > get what you are asking for:
> >
> > xml:
> > <?xml version="1.0"?>
> > <root>
> >   <child>1</child>
> >   <child>2</child>
> >   <child>3</child>
> >   <child>4</child>
> >   <child>5</child>
> > </root>
> >
> > java code:
> > List children = myElement.getChildren();
> > //first child element
> > Element firstElement = (Element)children.get(0);
> > //last child element
> > Element lastElement = (Element)children.get(children.size() - 1);
> > Element arbitraryElement = (Element)children.get(3);
> > int currentIndex = children.indexOf(arbitraryElement);
> > if(currentIndex >= 0 && currentIndex < children.size() + 1) {
> > //sibling after arbitrary element
> > 	Element nextElement = children.get(currentIndex + 1);
> > }
> >
> > You could also just use an iterator, as the List returned
> by getChildren()
> > is a standard java.util.List.
> >
> > Harry
> >
> > > -----Original Message-----
> > > From: jdom-interest-admin at jdom.org
> > > [mailto:jdom-interest-admin at jdom.org]On Behalf Of Meghasyam Bokam
> > > Sent: Monday, September 16, 2002 5:21 PM
> > > To: jdom-interest at jdom.org
> > > Subject: [jdom-interest] How to get nextSibling, prevSibling,
> > > firstChild
> > > and lastChild in JDOM?
> > >
> > >
> > > Hi all,
> > >
> > >     I am new to JDOM, and I see there are no methods to get
> > > nextSibling,
> > > prevSibling, firstChild and lastChild of an ELEMENT. Can
> > > anybody help me
> > > to write those specific methods which I can use in my application.
> > >
> > > Thanks for the help.
> > >
> > > Meghasyam.
> > >
> > >
> > > _______________________________________________
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> >
>