RE: [Jython-users] Getting PyException details from Java

[Updike, C. <Cla...@jh...>]

I have used the following static helper method.  It's based on=20
Py.formatException (but a bit simpler), and is designed to work=20
with exceptions thrown from an interpreter instance regardless=20
of whether the underlying exception is python or java (if I=20
recall correctly).

Good luck,
Clark

/**
 * Returns the exception message, akin to java exception's getMessage()
 * method (not supported properly in Jython).
 * @param pye a python exception instance=20
 * @return a string containing the python exception's message
 */
public static String getExceptionMessage(PyException pye) {
	// derivative of Jython's Py.formatException() method

	StringBuffer buf =3D new StringBuffer(128);
	if (pye.type instanceof PyClass) {
		buf.append(((PyClass) pye.type).__name__);
	} else {
		buf.append(pye.type.__str__());
	}
	if (pye.value !=3D Py.None) {
		buf.append(": ");
		if (__builtin__.isinstance(pye.value, (PyClass)
Py.SyntaxError)) {
			buf.append(pye.value.__getitem__(0).__str__());
		} else {
			buf.append(pye.value.__str__());
		}
	}
	return buf.toString();
}	=20

> -----Original Message-----
> From: jyt...@li...=20
> [mailto:jyt...@li...] On Behalf=20
> Of Kent Johnson
> Sent: Wednesday, May 31, 2006 12:33 PM
> To: jyt...@li...
> Subject: [Jython-users] Getting PyException details from Java
>=20
> Hi,
>=20
> When I catch a Jython exception from Java code, is there a=20
> clean way to retrieve the message from the exception? I am=20
> using this ugly bit:
>=20
> catch (PyException e) {
>    String msg =3D=20
> ((PyTuple)e.value.__getattr__("args")).list[0].toString();
>    ...etc
> }
>=20
> Dissecting the above:
> e.value is the actual Jython exception instance wrapped by=20
> the PyException. It is a PyObject so I use __getattr__ to=20
> retrieve the args.=20
> args is a PyTuple and must be cast as such before retrieving=20
> the actual list data.
>=20
> Thanks,
> Kent