How to get client certificate (X.509) using smack api on server side.

I want to extract fingerprint from X.509 certificate of client at server side code.

I want to do something like this:

KeyStore caKs = KeyStore.getInstance("JKS");

                                        caKs.load(new FileInputStream(new File("/home/piyush/workspace_may21/OpenADR2.0b-JAX-RS/src/security/keystore_ven _111111111111.jks")), caPassword.toCharArray());

                                        caCert = (X509Certificate) caKs.getCertificate("111111111111");

However instead of hardcoding the keystore, I want to get it from client request.

I am not able to figure this out.