Client certificate authentication with Spring WebClient

gistfile1.txt

public MyService(WebClient.Builder builder){
  this.client = buildCustomWebClient(builder, "https://example.com");
}

private SslContext createSSLContext() {
  try {
      KeyStore keyStore = KeyStore.getInstance(KeyStore.getDefaultType());
      keyStore.load(getClass().getClassLoader().getResourceAsStream(KEYSTORE_FILE), KEYSTORE_PASSWORD.toCharArray());

      KeyManagerFactory keyManagerFactory = KeyManagerFactory.getInstance("SunX509");
      keyManagerFactory.init(keyStore, KEYSTORE_PASSWORD.toCharArray());

      return SslContextBuilder.forClient()
              .keyManager(keyManagerFactory)
              .build();

  } 
  catch (Exception e) {
      throw new RuntimeException("Error creating SSL context.");
  }
}

private WebClient buildCustomWebClient(WebClient.Builder builder, String baseUrl){

  HttpClient client = HttpClient.create().secure(spec -> spec.sslContext(createSSLContext()));
  ClientHttpConnector connector = new ReactorClientHttpConnector(client);

  return builder
          .baseUrl(baseUrl)
          .clientConnector(connector)
          .build();
}