Sign the JAR File
Now you are ready to sign the JAR file.
Type the following on one line in your command window to sign the JAR file
Contract.jar, using the private key in the keystore entry aliased by
signLegal, and to name the resulting signed JAR file
jarsigner -keystore examplestanstore -signedjar sContract.jar Contract.jar signLegal
You will be prompted for the store password and the private key password.
jarsigner tool extracts the certificate from the keystore entry whose alias is
signLegal and attaches it to the generated signature of the signed JAR file.