PHP 没有从带有 AsyncTask 的 POST 请求接收数据

Question

I am trying to receieve a simple string from my PHP script by using a POST request in Android Studio. If I write for example echo "Hello"; I can receive this message in my app, but it seems like as soon as I send a POST request my webserver doesen't really get the message.

Here is how I do the POST request in my AsyncTask :

class HTTPReqTask extends AsyncTask<String, Void, String>
{
    Activity activity;
    OnDataSendToActivity dataSendToActivity;
    Context context;

    public HTTPReqTask(Context context)
    {
        this.context = context;
        dataSendToActivity = (OnDataSendToActivity) ((Activity) context);
    }

    @Override
    public String doInBackground(String... params)
    {
        HttpURLConnection urlConnection = null;
        String param1 = params[0];
        String line = "";
        String result = "";

        try
        {
            JsonObject postData = new JsonObject();
            postData.addProperty("a", "1");

            URL url = new URL(param1);
            urlConnection = (HttpURLConnection) url.openConnection();
            urlConnection.setRequestProperty("Content-Type", "application/json");
            urlConnection.setRequestMethod("POST");
            urlConnection.setDoOutput(true);
            urlConnection.setDoInput(true);
            urlConnection.setChunkedStreamingMode(0);

            OutputStream out = new BufferedOutputStream(urlConnection.getOutputStream());
            BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(out,"UTF-8"));
            writer.write(postData.toString());

            int code = urlConnection.getResponseCode();
            if (code !=  HttpURLConnection.HTTP_OK) {
                throw new IOException("Invalid response from server: " + code);
            }

            BufferedReader rd = new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));

            while ((line = rd.readLine()) != null)
            {
                result += line;
            }
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
        finally
        {
            if (urlConnection != null)
            {
                urlConnection.disconnect();
            }
        }

        return result;
    }

    @Override
    protected void onPostExecute(String s)
    {
        try
        {
            if(dataSendToActivity != null)
            {
                Log.i("Data", s);
                dataSendToActivity.sendData(s);
            }
        }
        catch(Exception e)
        {
            // Nichts
        }

    }
}

As you can see I am using this:

JsonObject postData = new JsonObject();
postData.addProperty("a", "1");

to generate my POST request.

The postData string is: {"a":"1"}

This is my PHP script:

$post = file_get_contents("php://input");
$data = json_decode($post, true);

print_r($data);

UPDATE 1

I added now writer.flush(); (Thanks to Andy) Now I'm getting this exception after sendung the request:

java.io.IOException: Invalid response from server: 500

So something with my PHP script is wrong.

Any suggestions?

Answer 1

I found now the problem. The problem was not serversided as I expected it.

I was logging in my code some informations for the POST request and there I found this:

Log.i("LOG", urlConnection.getOutputStream().toString());

gave me this:

buffer(com.android.okhttp.internal.http.HttpConnection$ChunkedSink@843d1c8).outputStream()

So I commented this line out:

urlConnection.setChunkedStreamingMode(0);

and it works fine. I get all my data I need.

I also updated my PHP script to this:

$post = file_get_contents("php://input");

if (!empty($post))
{
    $data = json_decode($post, true);
    $a = $data['a'];
}

Thanks for all the help!