How to check if all *.jars in my CLASSPATH really exists? Automatic check (not manual) possible?

Assume I have a long, long  CLASSPATH containing approx 20 (or more) *.jar
archives.
Is there a way to AUTOMATICALLY check if all mentioned *.jar files really
exist?

I could imagine a command (or even java class) which checks this from
command line:

java check_cp &CLASSPATH%

or similar

J.