/**
* Private worker method to attempt to use org.apache.env.Which.
*
* @param myContext an <code>ExpressionContext</code> passed in by the extension mechanism. This
* must be an XPathContext.
* @param factoryDocument providing createElement services, etc.
* @return a Node with environment info; null if any error
*/
private static Node checkEnvironmentUsingWhich(
ExpressionContext myContext, Document factoryDocument) {
final String WHICH_CLASSNAME = "org.apache.env.Which";
final String WHICH_METHODNAME = "which";
final Class WHICH_METHOD_ARGS[] = {
java.util.Hashtable.class, java.lang.String.class, java.lang.String.class
};
try {
// Use reflection to try to find xml-commons utility 'Which'
Class clazz =
ObjectFactory.findProviderClass(WHICH_CLASSNAME, ObjectFactory.findClassLoader(), true);
if (null == clazz) return null;
// Fully qualify names since this is the only method they're used in
java.lang.reflect.Method method = clazz.getMethod(WHICH_METHODNAME, WHICH_METHOD_ARGS);
Hashtable report = new Hashtable();
// Call the method with our Hashtable, common options, and ignore return value
Object[] methodArgs = {report, "XmlCommons;Xalan;Xerces;Crimson;Ant", ""};
Object returnValue = method.invoke(null, methodArgs);
// Create a parent to hold the report and append hash to it
Node resultNode = factoryDocument.createElement("checkEnvironmentExtension");
org.apache.xml.utils.Hashtree2Node.appendHashToNode(
report, "whichReport", resultNode, factoryDocument);
return resultNode;
} catch (Throwable t) {
// Simply return null; no need to report error
return null;
}
}