This little app is currently running fine on Xubuntu 22.04.3, as it
always has, but the Java versions installed there are somewhat
different. I decided to experiment, and for my fist venture I
uninstalled Oracle JDK 21. Afterwards the error message changed:
Exception in thread "main" java.lang.NoClassDefFoundError:
sun.misc.Launcher at userInterface.Start.<clinit>(Start.java:54)
I get the same error message whether I run from the launch script with
its two options or straight from the command line without them.
The only way I know how to tell what versions of Java are installed is
to launch LibreOffice Writer and go to Tools > Options > Advanced,
where it displays the versions of Java that LO found. It now lists
Oracle 8, Oracle 17, and Debian 17, where it used to include Oracle 21
as well. There's probably a faster, simpler way to get a list of
installed Javas from the command line, but I don't know it. For testing
it might also be useful if I could specify which of the installed Javas
the app is supposed to use. As it is, it just picks one based on who
knows what criteria.
In Xubuntu it appears that the installed Javas include JB-Java-jdk8.d.
On that the net leads me to openjdk8, and more links. The TreeForm app
there just runs, and I can't tell what Java it's actually using.
On Sun, 1 Oct 2023 10:32:59 -0700
Michael Ewan <michaelewa...@gmail.com> dijo:
>Unfortunately it sounds like there is a static string in the Java
>source or possibly in the jar file.
>You can disassemble the jar file with the "jar" command from the Java
>runtime.
>
>
>On Sat, Sep 30, 2023 at 6:31 PM John Jason Jordan <joh...@gmx.com>
>wrote:
>
>> I opened the launch script in a text editor and all it says is
>>
>> cd /home/jjj/Software/TreeForm103/TreeForm/
>> java -Xmx256m -Xms64m -jar TreeForm.jar
>>
>> With the command line in ~/Software/TreeForm103/TreeForm I just
>> copied the above line and ran it, and I got the same error message.
>> Then I deleted the -Xm... options and ran it bare, and again I got
>> the same error message. It might be useful to know what those
>> options do. Window size, maybe? In any event, they don't seem
>> related to the error message.
>>
>> Checking in Synaptic I have had OpenJDK installed the whole time. Is
>> there a way to tell the java -jar command which java to use? As for
>> paths, do you mean the path to the java? I know where the Oracle
>> Java 8 is located, because there were 'install' instructions telling
>> me to put it in /usr/java/jre1.8.0_381, so that's where I put it. It
>> must be correct because LibreOffice found it and listed it as
>> available. I don't know where the others are.
>>
>> There is a Help file with TreeForm, which says at the top:
>>
>> To install this software in your computer, unzip the folder
>> in any folder of your choosing.
>> This software requires Java 1.4.2 or higher to run. The Java
>> runtime can be downloaded from the <link>Java Website.</link>
>>
>> Michael Ewan <michaelewa...@gmail.com> dijo:
>> >Your start script may be calling for a specific path rather than a
>> >relative path in your JRE.
>> >Also try using OpenJDK instead of Oracle Java. Do a text search in
>> >your source code for that path.
>>
>> >> $ ./TreeForm_launch_script
>> >> Error: could not open
>> >> `/usr/lib/jvm/jdk-21-oracle-x64/lib/jvm.cfg'
>>
>>
