无法运行Java WebStart的两个实例

Question

I am unable to run more than one instance of java webstart at any given time.

For example, I am unable to run both the production & QA instance of an application at once, both of which are launched via java webstart. Additionally, I am unable to run the java webstart cache viewer at the same time as either the production or QA instance of my application.

I am however able to run any of the above three webstart launches when they are run in isolation of each other. When I try to bring up a second option, I see the 'Java Loading...' screen which then disappears and nothing happens.

Additionally, I have tried to delete the webstart cache (via the java webstart cache viewer) and I receive the following error regardless of which JRE I point to :

"Bad installation. Error invoking Java VM (execv) 'path to my javaw.exe'"

I expect both the problems I mention above are interlinked. I do not believe I have changed any configuration recently and I have been happily running java webstart for years.

Has anyone seen such a problem before?

Thanks, Jack

EDIT: When the second instance of webstart attempts to run, during the display of the 'Java Loading...' screen I can see in the task manager that a new javaw.exe process is spawned. This process almost immediately dies though. I'm not sure how to inspect the failure in that process, but I expect it is similar to the failure when trying to clear my cache through the webstart cache viewer.

Answer 1

You may be able to use javaws from the command line to run a second instance in -offline mode. The verbose option is handy, too.

javaws -offline -verbose MyApplication.jnlp

Answer 2

The reason may be the startup parameters for client java/javaw, which do not allow to run more than one instance of Java. For example because of set debug port. These parameters can be set in the command line or in the Java Control Panel -> Java -> button View.

Answer 3

I think it is because both instances of the application use the same folder as current working directory. I do not remember exactly but it is somewhere under user home and the folder contains the application name or something...

So, if this is correct the solution is to change the application name like "My Application - QA" vs. "My Application" used on production.

The name is somewhere in jnlp.xml.