You should never use generic interfaces in GWT-RPC unless you are sure you will use all classes that implement this interface anyways. A generic interface like Serializable will cause GWT-RPC to generate serializer classes for all classes the GWT compiler sees that implement Serializable. Even if you never use them! This will increase your final JS output. In your case the compiler finds PathImpl which implements Serializable and contains final fields. GWT-RPC does not support final fields and thus you get the above warning.
You should create a marker interface / base class to narrow down the scope of your type parameter so its under your control. Btw: The same also happens if you use java.util.List or similar in any class that goes through GWT-RPC. Even if you always use ArrayList as implementation the GWT generator will generate serializers for all possible lists GWT supports.. just in case. So be careful with generic interfaces. -- J. -- You received this message because you are subscribed to the Google Groups "Google Web Toolkit" group. To unsubscribe from this group and stop receiving emails from it, send an email to google-web-toolkit+unsubscr...@googlegroups.com. To post to this group, send email to google-web-toolkit@googlegroups.com. Visit this group at http://groups.google.com/group/google-web-toolkit. For more options, visit https://groups.google.com/groups/opt_out.