[proposal] XPath API for Java

[Bill de hÓra <bill@dehora.net>]

Hi,

I've been through a ton of DOM-in-Java programming in the last 12 
months. You learn early on to use XPaths where possible to keep the 
code flexible and clean. But one of the annoying about using XPath 
in Java is that it's all library specific.  The last thing I want to 
have to do is go through all my code and replace Xalan stuff with 
Jaxen stuff or Jaxen stuff with DOML3 stuff.

So here's a proposed api:


   package net.amadan.markup.xpath;

   import java.util.Map;
   import org.w3c.dom.Node;


   public interface XPath
   {
     /**
     * Match a xpath over a DOM Node.<p>
     *
     *
     * @param target the Node to match against.
     * @param xpath  the xpath as a String
     * @param namespaces    keys are namespace URIs,
     * values are namespace prefixes.
     * @return the Nodes matching the expression, a size of 0 
indicates no match.
     * @throws IllegalArgumentException if the xpath is illegal or a 
prefix is not bound to a key in <tt>namespaces</tt>
     */

     List match( Node target, String xpath, Map namespaces );
   }


I don't ever seem to need the extra step of preparing an xpath 
object and applying it later to a Node. I also figure managing any 
expression caching and so on is a fun thing to do for the 
implementor but gorp for the user.

Next step is a factory/plugin to this so anyone that does xpath in 
java  can register a provider. It'll be  the usual 
"FactoryFactory.getFactory().newInstance()" dance using a System 
property ("net.amadan.markup.xpath.driver").

Bill de hÓra