Re: [Jython-users] exceptions and inheritance

[<bc...@wo...>]

[Richard Gruet]

>Hi,
>
>If I define a Java 2 exceptions classes with one being a subclass of the
>other:
>
>public class BaseException extends Exception
>{ ... }
>
>public class DerivedException extends BaseException
>{ ... }
>
>And if the DerivedException is raised in a Java program, I can catch it
>in Jython as a DerivedException but *not* as a BaseException, i.e the
>following code:
>
>try:
>    # call the java prog that raises a DerivedException
>except DerivedException, e:
>    print "Got a DerivedException :", e
>
>... will display "Got a DerivedException : ...." (which is OK)
>
>whereas the code:
>
>try:
>    # call the java prog that raises a DerivedException
>except BaseException, e:
>    print "Got a BaseException :", e
>else:
>    import sys
>     exc_type, exc_value, exc_traceback = sys.exc_info()
>     print 'uncaught exception', exc_type, exc_value, exc_traceback
>
>...will display "uncaught exception ..." instead of "Got a
>BaseException..."
>
>This looks abnormal to me!
>Am I missing something or is it a bug ? Thanks for any clue.

The code belows works for me. Could you create a small standalone
example of the problem?

regards,
finn

------------ BaseException.java ------------
public class BaseException extends Exception {  }

------------ DerivedException.java ------------
public class DerivedException extends BaseException {  }

------------ j.java ------------
public class j {
    public static void foo() throws BaseException {
         throw new BaseException();
    }

    public static void bar() throws BaseException {
         throw new DerivedException();
    }

    public static void baz() throws DerivedException {
         throw new DerivedException();
    }
}


------------ tst.py ------------
import j, BaseException, DerivedException

try:
    raise DerivedException()
except DerivedException, e:
    print "Got a DerivedException :", e


try:
    raise DerivedException()
except BaseException, e:
    print "Got a BaseException :", e
else:
    import sys
    exc_type, exc_value, exc_traceback = sys.exc_info()
    print 'uncaught exception', exc_type, exc_value, exc_traceback

try:
    j.bar()
except DerivedException, e:
    print "Got a DerivedException :", e

try:
    j.bar()
except BaseException, e:
    print "Got a BaseException :", e

try:
    j.foo()
except BaseException, e:
    print "Got a BaseException :", e
else:
    import sys
    exc_type, exc_value, exc_traceback = sys.exc_info()
    print 'uncaught exception', exc_type, exc_value, exc_traceback

try:
    j.baz()
except BaseException, e:
    print "Got a BaseException :", e