Q:

Serving java 1.8 source in jar for JWS as static file

I've put a .jar file of source 1.8 as as static file for the client to launch via JWS.  However, when i try to update my app, i receive the following error:
Unable to update app: Class file is Java 8 but max supported is Java 7: path-to-my-jar
Which seems to indicate that gae is recognizing the classes in my jar as servlets, which can only be written in Java 7, however they aren't and i don't intend to run them as servlets. 
My appengine-web.xml looks like this: 
<? xml version="1.0" encoding="utf-8"? >
<appengine-web-app xmlns="http://appengine.google.com/ns/1.0">
<application>projectid</application>
<version>0.1</version>
<threadsafe>true</threadsafe>
<static-files>
    <include path="/**.jnlp"/>
    <include path="/**.jar"/>
</static-files>
<system-properties>
    <property name="java.util.logging.config.file" value="WEB-INF/logging.properties"/>
</system-properties>

How can i fix this? 

A:

Looking at the source code here there is no way to switch off the check for the Java version - even if you just want to serve the JAR file and not execute it.  I believe the check was introduced with App Engine SDK version 1.9.25.  I reverted back to App Engine SDK 1.9.24 and was able to deploy again.