How to Get Package Versioning Information
If a JAR has an implementation title, version or vendor set in its manifest, you can retrieve this from the package.
For any Class, you can get its implementation data like this:
Package p = getClass().getPackage();
System.out.println("Title: "+p.getImplementationTitle());
System.out.println("Version: "+p.getImplementationVersion());
System.out.println("Vendor: "+p.getImplementationVendor());
If a class did not come out of a JAR with those values set, the methods will return null.
Analog to this you can also get the specification values from the Package.