// You can add your own xpath functions.
FOMXPath fxpath = (FOMXPath)xpath;
Map<QName, Function> functions = fxpath.getDefaultFunctions();
functions.put(AlternateLinkFunction.QNAME, new AlternateLinkFunction());
fxpath.setDefaultFunctions(functions);
List<Link> links = fxpath.selectNodes("abdera:altlinks(/a:feed/a:entry)", feed);
System.out.println(links);
}
public static class AlternateLinkFunction implements Function {