What is jar signing in java?
what is jar signing? can we customize it? i mean having our own signature.
Jar signing is the process of applying a digital signature to a jar file so the receiver, using your public key, can verify its authenticity.
Yes you can use it. You just need to create a key and add it with keytool.
See JAR Signing.
It's just a facility for ideally getting users to grant your application greater security privileges based on the signature. You NEED to have your own signature, though in asking if you can customise it I'm not sure you really understand the 'why' behind signatures. A pretty good article from Sun's official docs explains it better than I could: