I installed and verified installation of Green as specified in documentation. I have an Eclipse 3.3 environment with GEF 3.3 and Java 1.6 on a Suse Enterprise Linux 10.3 platform. When I try to set Green preferences I get the following error…
“Unable to create the selected preference page. (Time of error: December 4, 2007
3:53:53 PM EST)
major.minor version 49.0)
I tried building class diagrams by right clicking on a package and selecting GreenUML->Add to New Class Diagram. I got the following error…
“Chosen operation is not currently available.”
Are there other dependencies to Green 3.0 other than Eclipse 3.3 and GEF 3.3? If not, any idea what the problem may be?
I am getting the same error on Windows XP.
This is not an OS-specific issue. This problem is related to the version of the JRE or JDK you're using to run your IDE.
If you look at your PATH and JAVA_HOME environment variables (in System Properties > Advanced > Environment Variables in Windows), you'll notice that it points to an older JVM (perhaps 1.4.2), which is incapable of running the plugins, which were developed in Java 5 (or perhaps later; I don't know what the group is using anymore, but they moved on from 1.4.2 a while ago).
In short, the version of Java required to load the plugins is newer than the one your OS is trying to load them with.
Either change your environment variables to point to a newer JRE or remove the older JRE from your system.
In Linux, you can temporarily change your variables in BASH using the export directive. I'd do this as part of a script and place the script in a directory in my path, such as /usr/local/bin (in fact, I use IntelliJ nowadays in Ubuntu for work, and part of the script sets my JDK home). Since the script only sets the PATH variable in the instance of BASH (or whatever shell you use to launch the program) used to run the script itself, it won't affect your other running processes. To set it system-wide, modify /etc/bashrc, or /etc/profile for non-BASH shells.
Thanks so much Blake. That did the trick!!
Awesome, I'm glad to hear it.
Green guys :-P could we post this solution this solution where appropriate, perhaps with an explanation? I can provide more details if necessary.
Eclipse uses two JREs (which can be the same one):
-One for initializing Eclipse and its plugins (we'll call this [A])
-One for compiling and executing code within the IDE (we'll call this one [B])
The problem being experienced by users is that [A] is too old. Since you (the devs) aren't going to rollback [B] in your workspace (which would break a lot of Green's code), people are going to have to change [A] in order to use it. I've posted instructions on how to do this for Windows and Linux. I'd bundle similar instructions (or a link to them) with Green and its plugins, as well as post those instructions on the web site.
[B] can be set within the IDE. However, [A] is controlled by the OS. This doesn't have to be done either either OS by the administrator (i.e., in Windows, you can open a command prompt and set the PATH and JAVA_HOME variables manually, or write a script to set it, or pass the necessary JRE as a JVM argument; the same holds for Linux and I'm sure for Mac OS X). You could include instructions for both methods (system-level and instance-level).