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Ubuntu Installation

  • Wizard

    I've been using JMRI on my Windows laptop for a few years now.  Got tired of the larger laptop and bought one of those small Dell Mini 10 primarily to be able to take to train shows and control my trains on the road.  I purchased the mini with Ubuntu 8.04 LTS pre-loaded since I wanted a quick, easy to use machine with minimal overhead.  It's been a challenge getting the system useful, first with printing, USB modem and external monitor working.

    I now have a useful machine and to my dismay, JMRI is not working.  I followed the steps outlined in the installation guide, but when I tried to run the RXTXinstall command, I got the following error:

    Exception in thread "main" java.lang.NoClassDefFoundError: GetJavaHome
    Caused by: java.lang.ClassNotFoundException: GetJavaHome
            at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
            at java.security.AccessController.doPrivileged(Native Method)
            at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
            at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
            at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:276)
            at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
            at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)

    Java not found on this computer
    Please check that it is included in
    your path and that it is installed
    your current path is displayed below
    The command to change your path will most probably be:


    I installed the sun-java6-jdk as outlined in the installation guide with no errors and the Synaptic Package Manager shows it installed.

    Is there something else I need?  Perhaps it's the path statement?

  • Wizard

    I also ran the command java -version and I know java is installed:
    java -version
    java version "1.6.0_06"
    Java(TM) SE Runtime Environment (build 1.6.0_06-b02)
    Java HotSpot(TM) Server VM (build 10.0-b22, mixed mode)


  • Bob Jacobsen
    Bob Jacobsen

    You'll get a much quicker reply by bringing this up in the JMRI users group on Yahoo: