That is a solution, thanks for the fast response !
But at the moment the protocol handlers are part of our application.
In your solution the handler classes (with all dependencies) have to move to the server installation, in a module with a service extension.
A hotdeploy or dynamic registration of handlers is impossible.
Or can we register the handler as a service extension in our jar files ? I guess not, because the ModulearURLStreamHandlerFactory resolve this in a static initializer.
The "java.protocol.handler.pkgs" - mechanism is a standard java way (more or less) what we use since a long time.
It's hard to accept that this is impossible with the new AS7 and to change a long running, tested application.
What's the reason for this ClassNotFoundException ?