According to the spec , if source is null
XPath.evaluate(java.lang.String expression, InputSource source)
and
XPath.evaluate(java.lang.String expression, InputSource source, QName returnType)
should throw NPE

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java -version
java version "1.5.0-beta2"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0-beta2-b37)

javac Test3.java
java Test3
checkXPath23() - failed , expected NPE - but XPathExpressionException thrown
checkXPath28() - failed , expected NPE - but XPathExpressionException thrown

Testcase : Test3.java - also attached
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// checkXPath23()
// checkXPath28()
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathFactory;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathFactoryConfigurationException;
import javax.xml.xpath.XPathExpressionException;

import org.xml.sax.InputSource;

import java.io.FileInputStream;


public class Test3 {

   FileInputStream fis = null;
   InputSource iSource1 = null;
   Test3 () {}
    
    // main()
    public static void main(String[] argv) {
        Test3 test3 = new Test3();
        test3.checkXPath23();
        test3.checkXPath28();
    }
   
    // test for XPath.evaluate(java.lang.String expression, InputSource source) - default returnType is String
    // source is null , should throw NPE
    private void checkXPath23() {
     try{
     XPathFactory xpathFactory = XPathFactory.newInstance();
     if( xpathFactory instanceof XPathFactory ){
     XPath xpath = xpathFactory.newXPath();
if ( xpath instanceof XPath ){
String expression = "/widgets/widget[@name='a']/@quantity";
String quantity = (String) xpath.evaluate(expression, iSource1);
System.out.println("checkXPath23() : failed - expected NPE not thrown ");
}
     else{
     System.out.println("checkXPath23() failed - xpath not instance of XPath");
     }
     }else{
     System.out.println(" checkXPath23() failed - creating instance of XPathFactory ");
     }
     }catch( NullPointerException npe ){
     System.out.println(" checkXPath23() - passed , expected NPE thrown ");
     }catch(XPathFactoryConfigurationException xpfce ){
     System.out.println(" checkXPath23() - failed , Default object model not available ");
     }catch(XPathExpressionException xpee ){
     System.out.println(" checkXPath23() - failed , expected NPE - but XPathExpressionException thrown "+xpee.getMessage());
     }catch(Exception e){
     System.out.println(" Exception thrown - checkXPath23() failed ");
     }
    }

    // test for XPath.evaluate(java.lang.String expression, InputSource source, QName returnType)
    // source is null , should throw NPE
    private void checkXPath28() {
     try{
     XPathFactory xpathFactory = XPathFactory.newInstance();
     if( xpathFactory instanceof XPathFactory ){
     XPath xpath = xpathFactory.newXPath();
if ( xpath instanceof XPath ){
String expression = "/widgets/widget[@name='a']/@quantity";
String quantity = (String) xpath.evaluate(expression, iSource1, XPathConstants.STRING);
System.out.println("checkXPath28() : failed - expected NPE not thrown ");
}
     else{
     System.out.println("checkXPath28() failed - xpath not instance of XPath");
     }
     }else{
     System.out.println(" checkXPath28() failed - creating instance of XPathFactory ");
     }
     }catch( NullPointerException npe ){
     System.out.println(" checkXPath28() - passed , expected NPE thrown ");
     }catch(XPathFactoryConfigurationException xpfce ){
     System.out.println(" checkXPath28() - failed , Default object model not available ");
     }catch(XPathExpressionException xpee ){
     System.out.println(" checkXPath28() - failed ,expected NPE - but XPathExpressionException thrown "+xpee.getMessage());
     }catch(Exception e){
     System.out.println(" Exception thrown - checkXPath28() failed ");
     }
    }

}

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