[Php-java-bridge-users] IllegalArgumentException when passing correct object

[<php...@li...>]

Hello,

I'm working on a project that needs pdfbox. I need to call a method which
expects a subclass from abstract-class ProtectionPolicy. If i pass this
object i get an IllegalArgumentException:
Fatal error: Uncaught [[o:Exception]:"java.lang.Exception: Invoke failed:
[[o:PDDocument]]->protect((o:ProtectionPolicy)[o:StandardProtectionPolicy]).
Cause: java.lang.IllegalArgumentException

Documentation:
http://www.pdfbox.org/javadoc/org/pdfbox/pdmodel/encryption/StandardProtectionPolicy.html

I believe i'm using it the right way. Anyone got an idea what i'm doing
wrong?
My code:
$ap = new Java("org.pdfbox.pdmodel.encryption.AccessPermission");
$ap->setCanModify(false);
$oDoc = new Java("org.pdfbox.pdmodel.PDDocument");
$oProtect = new Java("org.pdfbox.pdmodel.encryption.StandardProtectionPolicy
","test","test",$ap);
$doc = $oDoc->load( "/home/www/testserver/webapp/upload/test.pdf");
$doc->protect($oProtect);
$doc->save("/home/www/testserver/webapp/htdocs/testcases/out/testoutput.pdf");

Thanks in advance,

Gilbert