[PLUG] Java genius needed

John Jason Jordan johnxj at comcast.net
Sun Jan 20 19:00:39 UTC 2008


For a couple of years I have had a Java application installed on Gutsy x86_64 that does syntax trees. Here are the links:

Author's website:
http://www.ece.ubc.ca/~donaldd/index.htm
Program home page:
http://www.ece.ubc.ca/~donaldd/treeform.htm
Sourceforge download page:
http://sourceforge.net/project/showfiles.php?group_id=159595

What I have installed is version 0.2, which never worked very well. A few days ago the author released version 1.0. I have downloaded and installed it, but when I try to run it I get:

jjj at Devil7:~$ java -Xmx256m -Xms64m -jar /home/jjj/Software/TreeForm/TreeForm.jar 
Exception in thread "main" java.lang.UnsupportedClassVersionError: userInterface/Start (Unsupported major.minor version 49.0)
        at java.lang.ClassLoader.defineClass0(Native Method)
        at java.lang.ClassLoader.defineClass(ClassLoader.java:539)
        at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:123)
        at java.net.URLClassLoader.defineClass(URLClassLoader.java:251)
        at java.net.URLClassLoader.access$100(URLClassLoader.java:55)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:194)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:187)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:289)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:274)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:235)
        at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:302)
jjj at Devil7:~$ 

The memory options in the above command line are from a readme file in the zipped download. Deleting them doesn't make any difference, but that doesn't surprise me because the above errors all seem to be related to classes. 

I have Java 1.4.2 (Blackdown, or whatever it is now in Synaptic), Sun 1.5 and Sun 1.6. For 1.6 I have downloaded and installed upgrade 4 from Sun's website. According to the program website TreeForm is supposed to be compatible with all of these. 

I e-mailed the author last night and this morning received a response:

------
I have seen one other with difficulty running TreeForm on a 64 bit system.  I do not know
why except to say you need to run it on Java 1.5 because I no longer have the ability to
test on 1.6 until Mac releases that version.
Believe it or not I don't know how to do this in the command line and if you can find out
I'd love to know the answer.  I'll post it on sourceforge and add it to my batch command!
------

Having difference versions of Java installed always struck me as weird, although I have done so for a long time without problems. But one question is, how do I specify on the command line that it run on 1.5?

>From googling I gather that you can add classes, but I don't even know what a class is, let alone if this is accurate or how to do it. I know nothing of Java (or any programming language, for that matter). Would adding classes solve the above problems?

Any other suggestions?



More information about the PLUG mailing list