* Get the parameters types from the function signature.
* @return An array of parameter class names
*/
private String[] getParameters(ELNode.Function func)
throws JasperException {
FunctionInfo funcInfo = func.getFunctionInfo();
String signature = funcInfo.getFunctionSignature();
ArrayList params = new ArrayList();
// Signature is of the form
// <return-type> S <method-name S? '('
// < <arg-type> ( ',' <arg-type> )* )? ')'
int start = signature.indexOf('(') + 1;