Question

我正在尝试从ip address获取URL，它会在android中返回NULL，但网址在浏览器中正常工作

到目前为止

代码：

class ipaddress extends AsyncTask<String, String, String> {

    Context context;

    String ipaddress;

    public ipaddress(Context ctx)
    {
        context = ctx;
    }

    @Override
    protected void onPostExecute(String result) {

        if (result == null)
        {
            Toast.makeText(context, "null", Toast.LENGTH_SHORT).show();
        }else{
            Toast.makeText(context, "not null", Toast.LENGTH_SHORT).show();
        }

    }

    @Override
    protected String doInBackground(String... params) {

        String web_url = "https://api.ipify.org/?format=json";

        try {

            URL url = new URL(web_url);

            HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();

            httpURLConnection.setRequestMethod("GET");

            httpURLConnection.setDoOutput(true);

            httpURLConnection.setDoInput(true);

            OutputStream outputStream = httpURLConnection.getOutputStream();

            BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream, "UTF-8"));

            String verification_data = URLEncoder.encode("format", "UTF-8") + "=" + URLEncoder.encode("json", "UTF-8");

            bufferedWriter.write(verification_data);

            bufferedWriter.flush();

            bufferedWriter.close();

            outputStream.close();


            InputStream inputStream = httpURLConnection.getInputStream();

            BufferedReader bfreader = new BufferedReader(new InputStreamReader(inputStream,  "iso-8859-1"));

            String result = "";

            String line = "";


            while ((line = bfreader.readLine()) != null)
            {
                result += line;
            }

            bfreader.close();

            inputStream.close();

            httpURLConnection.disconnect();

            return result;

        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }


        return null;
    }
}

调用方法：

 ipaddress ip = new ipaddress(getActivity());

 ip.execute();

当我在浏览器中打开URL时，我得到了准确的结果，但是当我使用此代码访问Android上的URL时，它返回NULL

请告诉我我犯了什么错误。

Answer 1

我没有足够的声誉来评论，所以决定使用答案。除非你学习以便熟悉Java和Android，否则我建议你使用像OkHttp by Square这样的库。它使您的工作变得更加容易。

url在浏览器中工作正常但在android中使用异步任务返回null

1 个答案: