J9 JVM how to run a jar file

Manifest-Version: 1.0
Main-Class: MyViewer

I've already put that into the manifest file and it runs fine on windows. But on pocket pc...there is no program associated with jar files.

Hi there,

Using the JVM on pocket PC is different from normal usage. To use the virtual machine, invoke j9.exe or j9w.exe. The first one is equivalent to java.exe in traditional J2SDK, the second is equivalent to javaw.exe in that environment. The j9w.exe starts the application without generationg command line output. In other words, it starts silently. For development purposes, j9.exe is better, while for final sofware releases j9w.exe is probably more indicated.

In order to run applications in the pocket PC, you must always use full path names in your applications. This includes the options and parameters to your java application. The pocket PC and the j9 virtual machie do not understand relative paths. Also, the j9.exe command line cannot exceed 256 characters in length. If the length of the j9.exe parameters exceeds 256, the program execution may not succeed, some classes in the classpath may not be found or some parameters may be missed.

So, try invoking the jar file as j9.exe... Hope this helps.

Thanks, smithuns. Using j9 I can see a console window now (which helps), but I'm wondering about this error message: (is it a problem with the j9 jvm or my program?)

Exception in thread "main" java.lang.UnsupportedClassVersionError: (MyViewer) bad major version at offset=6
      at java.lang.ClassLoader.defineClassImpl(Native Method)
      at java.lang.ClassLoader.defineClass(Unknown Source)
      at java.security.SecureClassLoader.defineClass(Unknown Source)
      at java.net.URLClassLoader.findClassImpl(Unknown Source)
      at java.net.URLClassLoader$4.run(Unknown Source)
      at java.security.AccessController.doPrivileged(Unknown Source)
      at java.net.URLClassLoader.findClass(Unknown Source)
      at com.ibm.oti.vm.URLSystemClassLoader.findClass(Unknown Source)
      at java.lang.ClassLoader.loadClass(Unknown Source)
      at com.ibm.oti.vm.URLSystemClassLoader.loadClass(Unknown Source)
      at java.lang.ClassLoader.loadClass(Unknown Source)

Hi there,

The problem UnsupportedClassVersionError stems when you attempt to run an old bytecode (.class) on a newwer JVM or vice versa. So, if you have teh sources, I would recommend you to compile them on the newer JVM. This should help in most cases. I think this is the solution to your exisiting problem. Just try this and let us know if you have the same errors.

Bye for now and have a great day.

I recompiled the jar file, works on windows and linux, but same error for pocket pc.

Java -version on windows gives me this:

java version "1.5.0_04"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_04-b05)
Java HotSpot(TM) Client VM (build 1.5.0_04-b05, mixed mode, sharing)

Hi missiles,

thats pretty wierd, I would say! It works on PC and Linux, but not on PP! thats strange indeed! Well, its a very small query. You have a certain class in your Java file, isnt it? Well, do the class name and the file name match? In Java, the class name and the file name have to perfectly match for your applications to run. Thats the standard with Java. Else, there are errors like the once youve mentioned. So, please verify this. Might be this is a small error which we have apparently overseen.

Please feed in your progress. Bye for now and have a nice day.

Manifest-Version: 1.0
Created-By: 1.5.0_04 (Sun Microsystems Inc.)
Main-Class: MyViewer

That is my manifest file.

This is a manifest file from another jar file not created by me (which actually works on the pocket pc):

Manifest-Version: 1.0
Created-By: 1.4.1_03 (Sun Microsystems Inc.)
Main-Class: ImageViewer

And I tried recompiling this file with my 1.5 java compiler, and I got the same error message on the pocketpc as before. Do I have to get an earlier version of java to compile programs for J9?

I downloaded and installed the java SDK version 1.4.1_03, compiled my program using that, and that error message goes away! But then I get this one:

Exception in thread "main" java.lang.NoClassDefFoundError: javax.swing.JLabel
      at java.lang.Class.verifyImpl(Native Method)
      at java.lang.Class.verify(Unknown Source)
      at java.lang.Class.initialize(Unknown Source)

Did you try recompiling the source on the pp?  With either JDK this should get rid of the  UnsupportedClassVersionError.  I would use the latest pp JDK that you have.. and compile the source files on the device.