loginContext = new LoginContext("keycloak", new CallbackHandler() { @Override public void handle(Callback[] callbacks) { int len = callbacks.length; Callback cb; for (int i = 0; i < len; i++) { cb = callbacks[i]; if (cb instanceof NameCallback) { NameCallback ncb = (NameCallback) cb; ncb.setName(mdbuserName); } else if (cb instanceof PasswordCallback) { PasswordCallback pcb = (PasswordCallback) cb; pcb.setPassword(mdbUserPass); } } } }); loginContext.login();

Principal p = ctx.getCallerPrincipal();