Java version won't run on Mac

[Nobody/Anonymous]

I'm trying to run the Java version on a Mac running OS X 10.5.5 with a fully updated version of Java. The .jar will not run, even from the terminal. It gives this error message:

Exception in thread "main" java.lang.UnsupportedClassVersionError: Bad version number in .class file
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:675)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:124)
    at java.net.URLClassLoader.defineClass(URLClassLoader.java:260)
    at java.net.URLClassLoader.access$100(URLClassLoader.java:56)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:195)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:316)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:280)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
    at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:374)

Any ideas?

[M Hammel]

What version of Java do you have.  The web-site says GTD-Free requires 1.6, and it looks like you're running a lower version than that.

[Nobody/Anonymous]

Hi,
Can the next version be compiled with Java 1.5?  Or at the very least can the sources be available for download so I can recompile them myself?  I'm not sure what the advantage of using Java 1.6 is.

Karl

[Ike]

I have tried to downgrade but it was not straightforward so I gave up on that.
Especially that MacOX supports Java 1.6.

It is included in Mac OS X 10.5, Update 1:
http://www.apple.com/support/downloads/javaformacosx105update1.html

And you should change default or create a shortcut for gtd-free with right version:
http://blogs.sun.com/cmar/entry/java_1_6_finally_available

I'm not a mac user, am I missing something?

[Ike]

You should install and use Java version 1.6.

[Wes Garrison]

Had this issue, too.

> java -version
java version "1.5.0_13"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_13-b05-237)

Installed update (from Software Update)
Java for Mac OS X 10.5 Update 2
"Java for Mac OS X 10.5 Update 2 delivers improved reliability and compatibility for Java SE 6, J2SE 5.0 and J2SE 1.4.2 on Mac OS X 10.5.4 and later. This release updates Java SE 6 to version 1.6.0_07, J2SE 5.0 to version 1.5.0_16, and J2SE 1.4.2 to 1.4.2_18.

For more details on this update, please visit this website: http://support.apple.com/kb/HT2733
"

Then, from the article linked above, you need to update the symlink to the newest java version:
~> sudo rm /usr/bin/java
~> sudo ln -s /System/Library/Frameworks/JavaVM.framework/Versions/1.6/Commands/java /usr/bin/java

> java -version
java version "1.6.0_07"
Java(TM) SE Runtime Environment (build 1.6.0_07-b06-153)

Double-clicking the .jar works now.

[Nobody/Anonymous]

The easiest way to do this is to do a spotloght search for "Java Preferences" (or navigate to Applications, Utilities, Java folder).

Under the general tab, drag around the Java Application versions so v1.6 is at the top.

Double-click the JAR to launch.

I suppose I was a bit worried that the 64bit version of Java won't work on my Macbook Pro but it does.

Thanks for the nice work!
Karl

[Nobody/Anonymous]

Hi,

great application!

But I also have the problem with the JAVA 1.6 Issue at home.
Problem is, that Java 1.6 is not for PowerPC Macs and early Intel Macs (32bit).
And I don't think Apple will change this.

So, if there is a way of going to Java 1.5 it would be very nice!

Thanks
Markus

[Nobody/Anonymous]

Java 1.6 is not available for 32bit Intel Macs. Would have really liked to use this app. Shame.

[Peteredhair]

I'm running GTD-Free on my iMac with Lion.

Not a Mac looks app but works fine.