Jython

I've been creating a java web start swing/jython app for awhile now, and =
last week I ran into quite an odd problem.  I have yet to track down its =
exact source, but I do know the things that changed right before the =
problem occurred.  Let me describe the problem first:

After signing the jar files used by the application and deploying it to =
the server, the application works and is downloadable to the client, and =
will start execution.  However, after a point, swing JInternalFrames I =
create fail to ever appear.  The interpreted version of the app runs =
fine without this problem.  The problem appears after only three =
JInternalFrames have displayed.  No tracebacks occur that I can find, =
and the (jython) threads used to display and update these invisible =
JInternalFrames are running (I have a logging window that they each =
write to, and can see output from each thread).

Details:
-  I'm running jython 2.1, sun jdk 1.4.1_02, and utilize jfreechart =
(http://www.jfree.org/jfreechart).
-  The problem occurs regardless fo what client machine the web start =
app is run from (I.e., its not just my machine being funky)
-  The problem did not exist prior to the integration of jfreechart, but =
other code changes were made simultaneously.
       - somewhere during these changes, I did something that made me =
(later, when I went to make the jar) run into the ProxyMaker problem and =
was forced to change the -core option of jythonc to use -all instead, =
thanks to this this list =
(http://aspn.activestate.com/ASPN/Mail/Message/724323) I was able to =
find the solution of using -all, but not the reason _why_.  None of my =
code calls eval or anything similar, so why does my app suddenly need =
the compile support?
-  Due to the security restrictions put in place on web start apps, I =
cannot test the app without signing the jars - could my signing of the =
third-part jfreechart jars have caused this problem? (Until I signed =
them, I still got security errors: what should I do if I am not to sign =
third party jars?)
-  how can I trap for exceptions in an eventDispatch thread (or any =
pure-java thread) from jython?  I can trap and print traceback =
information for my threads to my logging window, but while runnign the =
app in interpreted mode I sometimes cause a bug that shows up via a =
eventDispatch thread exception - how would I trap for this (or other =
errors) so that I could show the traceback in my own custom logging =
window?

I have probably left out some important detail somewhere that would make =
my problem obvious, but I can't even find an instance of this sort of =
thing being reported.  Even if you don't know the solution to the =
overall problem, could someone step up and answer some of the =
sub-questions raised above?

Thank you in advance!

~Jon Franz

[Jython-users] running Jython code with Jedit Jython plugin From: patrickchamberlain <patrickchamberlain@ya...> - 2003-05-05 09:34 Reading the discussion about a possible Eclipse Jython plugin, got me looking at current alternatives that were mentioned. I've been using UltraEdit to write Jython and a DOS window to run it, but I'd like something more IDE like. Closest seems to be Jedit + Jython plugin, but I'm having some trouble using it ... I can't see how to pass some arguments when I use 'run current buffer' I think I must be missing something simple, but having spent a couple of hours looking everywhere I can think of ... thought it worth asking this list! thanks Patrick

Re: [Jython-users] Hello, odd problem here. From: Samuele Pedroni <pedronis@bl...> - 2003-05-06 14:57 At 02:20 05.05.2003 -0400, Jon Franz wrote: > - somewhere during these changes, I did something that made me > (later, when I went to make the jar) run into the ProxyMaker problem and > was forced to change the -core option of jythonc to use -all instead, > thanks to this this list > (http://aspn.activestate.com/ASPN/Mail/Message/724323) I was able to find > the solution of using -all, but not the reason _why_. None of my code > calls eval or anything similar, so why does my app suddenly need the > compile support? likely there is some Python class with a Java superclass that escapes jythonc static analysis - you should check jythonc compilation transcript - so its proxy will be created at runtime instead of statically >- Due to the security restrictions put in place on web start apps, I >cannot test the app without signing the jars - could my signing of the >third-part jfreechart jars have caused this problem? (Until I signed them, >I still got security errors: what should I do if I am not to sign third >party jars?) what kind of security errors? if it's classloader creation then it is related to proxy creation at runtime vs statically. >- how can I trap for exceptions in an eventDispatch thread (or any >pure-java thread) from jython? I can trap and print traceback information >for my threads to my logging window, but while runnign the app in >interpreted mode I sometimes cause a bug that shows up via a eventDispatch >thread exception - how would I trap for this (or other errors) so that I >could show the traceback in my own custom logging window? > JWS should allow to enable through preferences a Java console or to log the output to the console. Otherwise grep the java library code that comes with the JDK for sun.awt.exception.handler...

Re: [Jython-users] Hello, odd problem here. From: Jon Franz <jfranz@ne...> - 2003-05-06 15:27 > likely there is some Python class with a Java superclass that escapes > jythonc static analysis - you should check jythonc compilation transcript - > so its proxy will be created at runtime instead of statically I'll go digging, thanks! > > >- Due to the security restrictions put in place on web start apps, I > >cannot test the app without signing the jars - could my signing of the > >third-part jfreechart jars have caused this problem? (Until I signed them, > >I still got security errors: what should I do if I am not to sign third > >party jars?) > > what kind of security errors? if it's classloader creation then it is > related to proxy creation at runtime vs statically. Not just that - the jfreechart classes, and my own, interface to save-as dialogs and printing, which are both local machine and security restricted. signing the apps made the sec errors go away, but now I'm having the problem with hidden windows. per another sugestion, I'm looking into invokeLater > JWS should allow to enable through preferences a Java console or to log the > output to the console. I'll give this a shot, thanks!

Re: [Jython-users] proxy classes (was Hello, odd problem here.) From: Jon Franz <jfranz@ne...> - 2003-05-06 16:11 I'm not seeing anything about a proxy class being made/needed, but I am seeing this: Creating adapters: java.awt.event.ActionListener used in test59 Other than type/function sigs for each method in the class, what would I do to get jython to use static compilation for this? > likely there is some Python class with a Java superclass that escapes > jythonc static analysis - you should check jythonc compilation transcript - > so its proxy will be created at runtime instead of statically

Re: [Jython-users] proxy classes (was Hello, odd problem here.) From: Samuele Pedroni <pedronis@bl...> - 2003-05-06 23:16 At 12:11 06.05.2003 -0400, Jon Franz wrote: >I'm not seeing anything about a proxy class being made/needed, but I am >seeing this: > >Creating adapters: > java.awt.event.ActionListener used in test59 > >Other than type/function sigs for each method in the class, what would I do >to get jython to use static compilation for this? you should look for things that are missing but expected not those listed. Consider [it's a bit contrived] <ex.py> from java.lang import Object class X(Object): pass def y(): o, = [Object] # vs. o = Object class Y(o): pass return Y y() </ex.py> D:\exp\jy-esc-proxies>jythonc21 --jar ex.jar --core ex.py processing ex Required packages: java.lang Creating adapters: Creating .java files: ex module X extends java.lang.Object Compiling .java to .class... Compiling with args: ... 0 Building archive: ex.jar Tracking java dependencies: Y is nowhere to be seen. if you try java -jar ex.jar you get an error about ProxyMaker being needed. It's for classes with Java superclasses but not listed that you should look for. regards.

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