OkHttp3 TLS Enabled Client with custom PKCS12 Trust Store

TestOkHttp.java

OkHttpClient getTlsEnabledOkHttpClient() {
    try {
      final KeyStore keyStore = KeyStore.getInstance("pkcs12");
      try (final InputStream keystoreStream =
          ClassLoader.getSystemResource(KEYSTORE_RESOURCE).openStream()) {
        keyStore.load(keystoreStream, "changeit".toCharArray());
      } catch (IOException e) {
        throw new RuntimeException("Unable to load keystore.", e);
      }

      TrustManagerFactory trustManagerFactory =
          TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
      trustManagerFactory.init(keyStore);

      // build custom sslcontext with our custom trust manager
      SSLContext sslContext = SSLContext.getInstance("TLS");
      sslContext.init(null, trustManagerFactory.getTrustManagers(), new SecureRandom());

      // create okhttp client with custom ssl socket factory
      return new OkHttpClient.Builder()
          .sslSocketFactory(
              sslContext.getSocketFactory(),
              (X509TrustManager) trustManagerFactory.getTrustManagers()[0])
          .build();
    } catch (GeneralSecurityException e) {
      throw new RuntimeException(e);
    }
  }