[Jython-users] Newbie problem with applets

[James S. <bit...@ph...>]

Hi all,
firstly, I'm a newbie to both jython and pretty much to java in general (I've done a couple jobs in java, but nothing to write home about), 
so my problem  might just be something I'm doing wrong.  

I have written a small jython application which displayes a swing JTree that is dynamically loaded from a url via a WDDX (XML) packet 
for each node (i.e expand a node, application downloads packet, adds nodes to be shown...) .  Anyway, the app worked  really nicely, 
and it was time to turn my application into an applet (which is what I want this particular thing for), easy I thought.

So I just added
class wddxTreeApplet(swing.JApplet):

	def init(self) :	

		getContentPane().add(swing.JScrollPane(wddxTree("Root Of Tree", "http://mortimer/
~boffin/treeViewDumper.cfm")))


to the file wddxTreeApplet.cfm that has all the required classes in it (aside from the supporting 3rd party ones which are in a couple of 
jars) ran jythonc over it to produce class files, shifted the class files into an appropriate location and write a dumm html page with an 
applet to call it .   Didn't work, the java console tells me this...

java.lang.ClassCastException: wddxTreeApplet

	at sun.applet.AppletPanel.createApplet(AppletPanel.java:579)

	at sun.plugin.AppletViewer.createApplet(AppletViewer.java:1178)

	at sun.applet.AppletPanel.runLoader(AppletPanel.java:515)

	at sun.applet.AppletPanel.run(AppletPanel.java:293)

	at sun.plugin.navig.motif.MotifAppletViewer.maf_run(MotifAppletViewer.java:127)

	at sun.plugin.navig.motif.MotifAppletViewer.run(MotifAppletViewer.java:123)

	at java.lang.Thread.run(Thread.java:484)


Ok, so I figured I'd better check that applets are working in my browser still, head over o the jython applet demos, yep - alll still work.  So, 
I take the code for the HelloWorld applet as on the jython applets main page (there's a missing comma in that code as displayed btw) 
because I know that works, put it into a jython file called testApplet.py as 

from java.applet import Applet 

class testApplet(Applet):

	def paint(self, g):

		g.drawString("Hello from Jython!", 20, 30)

	
compile with jythonc, move classes (well, everything in jpywork directory) to approprioate place, write an html file, test it, and still doesn't 
work...

java.lang.ClassCastException: testApplet

	at sun.applet.AppletPanel.createApplet(AppletPanel.java:579)

	at sun.plugin.AppletViewer.createApplet(AppletViewer.java:1178)

	at sun.applet.AppletPanel.runLoader(AppletPanel.java:515)

	at sun.applet.AppletPanel.run(AppletPanel.java:293)

	at sun.plugin.navig.motif.MotifAppletViewer.maf_run(MotifAppletViewer.java:127)

	at sun.plugin.navig.motif.MotifAppletViewer.run(MotifAppletViewer.java:123)

	at java.lang.Thread.run(Thread.java:484)


same error it seems.

So what am I doing wrong ?  Is it my jre/jdk  (blackdown linux 1.3.1, using plugin under both mozilla and opera with same results) ? Have 
I missed some vital step ? 

BTW: jython rocks, even if I can't get my own applets working :-)


---
James Sleeman