Issue with an automatic module

Alan Bateman Alan.Bateman at
Wed Aug 3 18:43:42 UTC 2016

On 03/08/2016 08:49, Paul Benedict wrote:

> Given that "automatic modules" are meant to be a migration path, I 
> think refusing any legacy jar adds an unfortunate surprise to 
> migrating. I understand the intent to throw FindException with regard 
> to real modules (has module-info.class), but why apply the same 
> restriction to *automatic* modules?
Named modules cannot contain types in the unnamed package. As per the 
discussion, then such types could be ignored but there is no guarantee 
that there aren't references to those types. There are several other 
reasons why a JAR file might be "rejected", the most obvious is where a 
module name cannot be derived from the name of the JAR file ("_.jar" for 

In general then there should no shame whatsoever in leaving some JAR 
files on the class path during migration. Automatic modules are the 
bridge for doing exactly that.


More information about the jigsaw-dev mailing list