Call REST API

RESTAPI.java

    private Optional<JsonObject> callRestApi(String url) {
        try {
            CredentialsProvider provider = new BasicCredentialsProvider();
            UsernamePasswordCredentials credentials =
                    new UsernamePasswordCredentials(System.getenv(Constant.EnvironmentVariable.USERNAME),
                            System.getenv(Constant.EnvironmentVariable.PASSWORD));
            provider.setCredentials(AuthScope.ANY, credentials);
            HttpClient client = HttpClientBuilder.create().setDefaultCredentialsProvider(provider).build();
            HttpResponse response = client.execute(new HttpGet(url));
            String json = EntityUtils.toString(response.getEntity(), "UTF-8");
            JsonElement jsonElement = new JsonParser().parse(json);
            return Optional.of(jsonElement.getAsJsonObject());
        } catch (IOException e) {
            logger.error("Failed to call api {}", url, e);
            return Optional.empty();
        }
    }