Node id problem

Question

Hi this is my problem.i have a jtree which a user adds nodes to and from.now, when a duplicate is added to the tree, i assign a unique index to the end of the defaultmutabletreenode, for example, if i have "book" and i input another entry called"book" the new book becomes book[1] anothre book entry would be added as book[2] etc...
Now, each time the user adds an entry to the jtree, i try to create a similar entry to be outputted to an xml file. i can create the root ok, and i can creare an element ok too, doc.createElement("book");, happy days. But, lets now imagine that i have already outputted an entry to the xml file that looks like <book /> and a new entry also called "book" is ready to be outputted. This new book entry will look like "book[1]" before it is written to the xml file, where the [1] is a unique identifier for this node. what i now do is, try to create an element like so:
doc.createElementNS("book[1]", "book"); with "book[1]" as the unique identifier, yet this throws an exception saying that there are illegal characters present. Fair enough, but i really need to know how to use the above method properly.i will need to have a unique identifier for duplicates, so i can distinguish between them when i want to retrieve a node uniquely to append a child onto it or add a value to it.i will not be able to do this if there are duplicates.can some1 please help me as to how, i can uniquely keep track of each node that i output to an xml file.
please help!

Answer 1

What you're doing is trying to generate:<book>
  <book:book xmlns:book="book[1]"/>
</book>Which isn't legal, as the namespace must be a URI, and 'book[1]' isn't a legal URI.
You could legally use a urn or an http url or something as the namespace to mean 'this thing called book is in fact of a completely unrelated type to the other things called book in this list', in which case your XML will be:<book>
  <book:book xmlns:book="http://my.doman.com/book1"/>
</book>But it would be very wierd to use the namespace URI mearly to provide uniqueness, and any other XML tools won't be expecting that sort of use, whereas some will work out the box with @xml:id, and many will work with @id using a DTD or schema.
<book>
  <book id='z1'/>
</book>Pete