Tried the Javadoc ?

http://java.sun.com/j2se/1.5.0/docs/api/java/security/KeyStore.html

if you are only doing some not-so-commercial project, i would secretly
suggest you using
sun.security.tools.KeyTool.main(new String[] {"-genkey", "-alias",
"me", ....});
which is in fact the real class behind the keytool command.

Sun never encourages you to try any sun.* classes, so use it at your
own risk.