GWT 2.8 should support JDK 7, but if you want to use Java 8 features then indeed you need to use a JDK 8 to JavaC your classes.
You could possibly exclude your client code from being compiled with JavaC, and only processed by GWT. Alternatives I can think of are: - use Maven Toolchains to use JDK 7 and JDK 8 in the same build; - use JDK 8 and retrolambda: https://github.com/orfjackal/retrolambda - split your code into 2 projects/modules, compiled in 2 phases: mvn install the client code with JDK8, then mvn appengine:update the server code with JDK7, which has a dependency in the client code (resolved from local Maven repo). The cleaner solution IMO is to use separate JDKs (or proper cross-compilation, with bootclasspath et al); either with toolchains or separate build phases. Retrolambda would need some testing in a Java 7 environment to confirm the transformation went well. Also, Animal Sniffer on your server code would help, in case you don't compile it with a JDK7. -- You received this message because you are subscribed to the Google Groups "GWT Users" 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 https://groups.google.com/group/google-web-toolkit. For more options, visit https://groups.google.com/d/optout.
