jython/java inheritance question?

[Matt Newcomb]

G'day,

Hi, I've got a java class called ChannelIterator Algorithm which
extends SampledChannelG roupIteratorAlg orithm.
SampledChannelG roupIteratorAlg orithm has a stub method
processSampledC hannelGroup(Obj ect[] in, Object[] out) that is
overridden by a method in the ChannelIterator Algorithm class.

Now, I've got a jython script that contains a class that extends the
ChannelIterator Algorithm class ( are you having fun yet? ) and it's
got a processSampledC hannelGroup method that looks like this:

class testalg(Channel IteratorAlgorit hm):
def processSampledC hannelGroup(sel f, inGroups, outGroups):
if (self.samplesTo Pass!=0):
print "samples left: %d" % self.samplesToP ass
ChannelIterator Algorithm.proce ssSampledChanne lGroup(self,
inGroups,
outGroups)

However, each time I try to run this script I get this exception:

2003-10-29 05:26:29 ERROR:: spigot_1.handle Data() encountered a fatal
Exception:Trace back (innermost last):
File "<string>", line 187, in processSampledC hannelGroup
AttributeError: class
'gov.nasa.gsfc. irc.algorithms. ChannelIterator Algorithm' has no
attribute 'processSampled ChannelGroup'

What?!?!?! Why an attribute and not a method? And why, given that
yes there is an implementation of processSampledC hannelGroup in the
ChannelIterator Algorithm class and yes it really looks like:

protected void processSampledC hannelGroup
(Object[] inputChannelDat aBuffersForGrou p,
Object[] outputChannelDa taBuffersForGro up)

would there be an issue?

Is this a feature that I'm unaware of?

Thanks for any suggestions,

Matt Newcomb
Yerkes Observatory
Williams Bay, WI 53191

[Alan Kennedy]

Re: jython/java inheritance question?

Matt Newcomb wrote:[color=blue]
> I've got a jython script that contains a class that extends the
> ChannelIterator Algorithm class ( are you having fun yet? ) and it's
> got a processSampledC hannelGroup method that looks like this:
>
> class testalg(Channel IteratorAlgorit hm):
> def processSampledC hannelGroup(sel f, inGroups, outGroups):
> if (self.samplesTo Pass!=0):
> print "samples left: %d" % self.samplesToP ass
> ChannelIterator Algorithm.proce ssSampledChanne lGroup(self,
> inGroups,
> outGroups)
>
> However, each time I try to run this script I get this exception:
>
> 2003-10-29 05:26:29 ERROR:: spigot_1.handle Data() encountered a fatal
> Exception:Trace back (innermost last):
> File "<string>", line 187, in processSampledC hannelGroup
> AttributeError: class
> 'gov.nasa.gsfc. irc.algorithms. ChannelIterator Algorithm' has no
> attribute 'processSampled ChannelGroup'
>
> What?!?!?! Why an attribute and not a method? And why, given that
> yes there is an implementation of processSampledC hannelGroup in the
> ChannelIterator Algorithm class and yes it really looks like:
>
> protected void processSampledC hannelGroup
> (Object[] inputChannelDat aBuffersForGrou p,
> Object[] outputChannelDa taBuffersForGro up)
>
> would there be an issue?[/color]

Yes: The method is protected, meaning that you cannot call it directly
as you are trying to above. See the following jython doc page for more
information

http://www.jython.org/docs/subclassing.html

This might work

#-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

class testalg(Channel IteratorAlgorit hm):

def processSampledC hannelGroup(sel f, inGroups, outGroups):

if (self.samplesTo Pass!=0):
print "samples left: %d" % self.samplesToP ass
self.super__pro cessSampledChan nelGroup(inGrou ps, outGroups)

#-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

HTH,

--
alan kennedy
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