java.lang.IncompatibleClassChangeError: the number of constructors during runtime and compile time for java.lang.Exception do not match

[John Moore]

Anyone come across this before? I'm getting an error on the production server which isn't showing up in development, whenever I throw an exception which is a simple subclass of Exception. This is the gist of the error:

"Caused by: java.lang.IncompatibleClassChangeError: the number of constructors during runtime and compile time for java.lang.Exception do not match. Expected 4 but got 5
        at util.PermissionsException.<init>(PermissionsException.groovy:9)"

Here's the class:

class PermissionsException extends Exception {

    public PermissionsException(String message) {
        super(message)
    }
}

Nothing at all out of the ordinary there, and in dev mode it's absolutely fine. I wondered whether it might be to do with developing with JDK 1.6 but running under JDK 1.7 (the only useful thing I could find on Google pointed to something like this), but I've now built the app with JDK 1.7 and the problem is still there. This is with Grails 2.0.4.

[John Moore]

Sorted this shortly after posting (always the way). It seems that Java 7 is rather fussier about constructors of superclasses. When I added in a zero-argument constructor to my class it worked fine and the error disappeared. This was not necessary with Java 6.

[John Moore]

For some reason, this problem is now back. Building with Java 7, deploying with Java 7, so there should be no problem there. I was able to reproduce it locally, then did a 'grails clean' and the problem has gone away again - for now. Why on earth might a 'grails clean' sort this one out, unless there were classes there built with Java 6 (which there weren't)? I'm worried about this one coming back on the server, so looking for any ideas. I think I may well switch back to Java 6, as I suspect it's something to do with Java 7, but what?