Java is reporting errors running the A+ Learning System. Any ideas how to fix them?

Question

I work for a local school district part time. They run a piece of software called A+ learning system. It uses the java runtime environment to do what it does. On one of our computers, it isn't running; opening a command prompt and typing out:

  java -jar als.jar

gives the following error messages.

    C:\als30\alsclient>java -jar als.jar > C:\alsdebuginfo.txt
    Exception in thread "main" java.lang.NoClassDefFoundError: javax/media/ControllerListener
     at java.lang.ClassLoader.defineClass1(Native Method)
     at java.lang.ClassLoader.defineClassCond(Unknown Source)
     at java.lang.ClassLoader.defineClass(Unknown Source)
     at java.security.SecureClassLoader.defineClass(Unknown Source)
     at java.net.URLClassLoader.defineClass(Unknown Source)
     at java.net.URLClassLoader.access$000(Unknown Source)
     at java.net.URLClassLoader$1.run(Unknown Source)
     at java.security.AccessController.doPrivileged(Native Method)
     at java.net.URLClassLoader.findClass(Unknown Source)
     at java.lang.ClassLoader.loadClass(Unknown Source)
     at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
     at java.lang.ClassLoader.loadClass(Unknown Source)
     at ALS.checkALSRunning(ALS.java:1017)
     at ALS.main(ALS.java:192)
   Caused by: java.lang.ClassNotFoundException: javax.media.ControllerListener
     at java.net.URLClassLoader$1.run(Unknown Source)
     at java.security.AccessController.doPrivileged(Native Method)
     at java.net.URLClassLoader.findClass(Unknown Source)
     at java.lang.ClassLoader.loadClass(Unknown Source)
     at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
     at java.lang.ClassLoader.loadClass(Unknown Source)
     ... 14 more

I really don't know enough about java or A+ learning system to be able to debug this stuff. My only hunch is that maybe the computer is running the wrong version of the Java Runtime Environment. Any shove in the right direction would be greatly appreciated.

Thanks in advance guys.

Answer 1

ClassNotFoundException usually means that a class is missing that it is expecting to be on the classpath. My guess is that it is expecting a system library, or a separate library, to be available (installed to the Java lib directory maybe) that isn't. Does that help at all?

Answer 2

It looks like the optional Java Media Framework is not installed.

You can get it here, along with installation instructions.