Android -使用InputStream获取数据，不返回任何内容/为空

try {
    URL url = new URL("http://example.com/data"); // 替换为你的请求URL
    HttpURLConnection connection = (HttpURLConnection) url.openConnection();
    connection.setRequestMethod("GET");
    connection.connect();

    int responseCode = connection.getResponseCode();
    if (responseCode == HttpURLConnection.HTTP_OK) {
        InputStream inputStream = connection.getInputStream();
        BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
        StringBuilder stringBuilder = new StringBuilder();
        String line;
        while ((line = reader.readLine()) != null) {
            stringBuilder.append(line);
        }
        String responseData = stringBuilder.toString();
        // 对responseData进行进一步处理
        reader.close();
    } else {
        // 处理请求失败的情况
    }
} catch (IOException e) {
    e.printStackTrace();
    // 处理异常情况
}