Is there really no wildcard adding for "jar -cvf my.jar classes\*.class" ?

When I try to execute a jar command like the following:

jar -cvf my.jar classes\*.class

then JVM gives me an error about non-existing files/folders.

However when I specify all the class files in detail:

jar -cvf my.jar classes\a.class classes\b.class ..... classes\z.class

then everything is fine.

Is there really no flag/option to let users pass wildcards for jar adding
operations ?

Cat