This Works:
appletviewer -J-Djava.security.policy=policy localApplet.html

-- Notes ---

save as page to start:
http://www.cs.unc.edu/~geom/LIGHTNING/applet/index.html

edit a copy of html:
localApplet.html

-Getting Applet:

wget http://www.cs.unc.edu/~geom/LIGHTNING/applet/LightningDemo.class
wget http://www.cs.unc.edu/~geom/LIGHTNING/applet/BackBuffer.class
wget http://www.cs.unc.edu/~geom/LIGHTNING/applet/Lightning.class
wget http://www.cs.unc.edu/~geom/LIGHTNING/applet/DAGNode.class

wget http://www.cs.unc.edu/~geom/LIGHTNING/applet/<Missing>.class


Decompile with jad: jadls158.zip
mkdir jad_out
./jad -o -d jad_out -s java *.class
cd jad_out
javac *.java

from recompiling found other missing classes:

wget http://www.cs.unc.edu/~geom/LIGHTNING/applet/APSF.class
wget http://www.cs.unc.edu/~geom/LIGHTNING/applet/FFT.class
wget http://www.cs.unc.edu/~geom/LIGHTNING/applet/Complex.class

now:
appletviewer localApplet.html

also getImage for filtering:
wget http://www.cs.unc.edu/~geom/LIGHTNING/applet/apsfShift.jpg

after adding stack traces and recompiling, found:

Exception in thread "AWT-EventQueue-1" java.security.AccessControlException: access denied (java.io.FilePermission /home/daniel/lightning/apsfShift.jpg read)
        at java.security.AccessControlContext.checkPermission(AccessControlContext.java:264)

so cannot read from local filesystem:

so copied a ALL policy file from carousel:

appletviewer -J-Djava.security.policy=policy recompiledApplet.html


Bingo!

To read the apsfShift filter: to P3 ascii readble ppm:
convert -compress none apsfShift.jpg  coco.ppm