HTTPURLConnectionでBasic認証を行う際の実装例

private void basicAuthFunction() throws IOException, ParseException {
    HttpURLConnection connection = null;
    try {
        final URL url = new URL(config.getRequestUrl());
        connection = (HttpURLConnection) url.openConnection();
        connection.setRequestMethod("GET");
        connection.setRequestProperty("Authorization", "Basic " + config.getEncodeAuthorization());
        connection.connect();

        streamFunction(connection);
    } finally {
        if (connection != null) {
            connection.disconnect();
        }
    }
}

private void streamFunction(HttpURLConnection connection) throws IOException, ParseException {
    try (final InputStream stream = connection.getInputStream();
         final BufferedReader reader = new BufferedReader(
                 new InputStreamReader(stream, StandardCharsets.UTF_8))) {

        final StringBuilder builder = new StringBuilder();
        String line;
        while ((line = reader.readLine()) != null) {
            builder.append(line);
        }

        final JSONObject obj = (JSONObject) new JSONParser().parse(builder.toString());
        final JSONObject data = (JSONObject) obj.get("data");
    }
}

参考

StringBuilderとStringBufferの違い -Qiita