Specification for the following method
http://jre.us.oracle.com/java/re/jdk/9/promoted/latest/docs/api/java/util/jar/JarFile.html#runtimeVersion--

says: "In most cases, runtimeVersion() is equal to Runtime.version()"
However by default this is true only for major version numbers so the following test line:

assertEquals( Runtime.version(), JarFile.runtimeVersion() )

will fail with the message like : "Expected equal to : "9-ea+135", was given: "9""

The spec deserves to be clarified.