solution for the message No -tsa or -tsacert is provided and this jar is not timestamped

Solution for the message

No -tsa or -tsacert is provided and this jar is not timestamped. Without a times
tamp, users may not be able to validate this jar after the signer certificate's
expiration date (2015-08-21) or after any future revocation date.

When you are (trying to sign) signing a jar this notice can be shown if the file is not timestamped.

To solve this thing the faster way is to add this part to your signing command line

-tsa http://timestamp.digicert.com

for example

jarsigner -storepass mypass -keypass mypass2 myjar.jar storek