xpath union operator with VTD XML Parser - vtd-xml

Question

Can someone please post an example for using union operator (|) with VTD XML parser ?
Below is not working in VTD XML parser but works in jxpath parser.
/a | /b

Answer 1

Ok, this is a quick example of union expression in action.
import com.ximpleware.AutoPilot;
import com.ximpleware.NavException;
import com.ximpleware.VTDException;
import com.ximpleware.VTDGen;
import com.ximpleware.VTDNav;
/**
* An issue that seems to exist in VTD-XML 2.12 and 2.13 (but not 2.11) that causes lookups for default namespace nodes
* to also pickup non-default namespaced nodes.
*/
public class VtdAutoPilotXpathIssueTest {
private static final String XML = "<a xmlns:x=\"" + "urn:test" + "\"><b id=\"1\"/><x:b id=\"2\"/><b id=\"3\"/></a>";
public static void main(String[] s) throws VTDException{
VTDGen vg = new VTDGen();
vg.setDoc(XML.getBytes());
vg.parse(false);
VTDNav vn = vg.getNav();
AutoPilot ap = new AutoPilot(vn);
ap.declareXPathNameSpace("abc", "urn:test");
ap.selectXPath("//b|/a");
int i=0;
while((i=ap.evalXPath())!=-1){
System.out.println(" token "+ vn.toRawString(i));
}
}
}