How to specify the client certificate on a JAX-WS client and client certificate authentication

I'm programming a JAX-WS client in Java. The access to the WebService is protected with a client certificate. I know the client certificate is right because I can get the WSDL in Firefox only if the client certificate was imported (in Firefox).

But I have problems to write my java application which should use the WebService. What I have do is following:

  MyOwnService svc = new MyOwnService(getServerURL(), CBACKUPSERVICE_QNAME);
...
...
private URL getServerURL() throws IOException {
  URL url = new URL((String) cfg.get(ConfigData.SERVER_URL));

  HttpsURLConnection con = (HttpsURLConnection) url.openConnection();

  try {
    con.setSSLSocketFactory(getFactory(new File("/etc/pki/wildfly/client.keystore"), "123456"));
  } catch (Exception exc) {
    throw new IOException("Client certificate error!", exc);
  }

  return url;
}

private SSLSocketFactory getFactory(File pKeyFile, String pKeyPassword ) 
  throws ... {

  KeyManagerFactory keyManagerFactory = KeyManagerFactory.getInstance("SunX509");
  KeyStore keyStore = KeyStore.getInstance("PKCS12");

  InputStream keyInput = new FileInputStream(pKeyFile);
  keyStore.load(keyInput, pKeyPassword.toCharArray());
  keyInput.close();

  keyManagerFactory.init(keyStore, pKeyPassword.toCharArray());

  SSLContext context = SSLContext.getInstance("TLS");
  context.init(keyManagerFactory.getKeyManagers(), null, new SecureRandom());

  return context.getSocketFactory();
}

But this didn't work. If I run this I get following exception in the MyOwnService constructor

java.security.InvalidAlgorithmParameterException: the trustAnchors parameter must be non-empty.

How is the correct way to implemnting a JAX-WS client which supports client certification?