HttpsUrlConnection EOFException

Question

I'm using the following code for post requests

public String executeHttpPost(String uri, String data) {

    HttpURLConnection conn = null;
    URL url = null;
    String s = null;

    try {

        url = new URL(uri);

         conn = (HttpURLConnection) url.openConnection();

        if (conn instanceof HttpsURLConnection) {
            Log.d("HTTPS", "HttpsUrl");
        }

        conn.setDoOutput(true);
        conn.setDoInput(true);
        conn.setRequestMethod("POST");
        conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");

        OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
        wr.write(data);
        wr.flush();

        DisplayResponseHeaders(conn);

        s = readStream(conn.getInputStream());
        Log.d("body", s);

    } catch (MalformedURLException e) {
        e.printStackTrace();
    } catch (IOException e) {
        s = null;
        e.printStackTrace();
    } finally {
        conn.disconnect();
    }
    return s;
  }

When I use it over http, all works good , but over https I get

 java.io.EOFException
 at libcore.io.Streams.readAsciiLine(Streams.java:203)
 at libcore.net.http.HttpEngine.readResponseHeaders(HttpEngine.java:573)
 at libcore.net.http.HttpEngine.readResponse(HttpEngine.java:821)
 at libcore.net.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:283)
 libcore.net.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:177)
 libcore.net.http.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:271)
 ru.fors.remsmed.fragment.NetHelper.executeHttpPost(NetHelper.java:234)
 ru.fors.remsmed.LoginActivity$UserLoginTask.doInBackground(LoginActivity.java:424)
 ru.fors.remsmed.LoginActivity$UserLoginTask.doInBackground(LoginActivity.java:1)
 android.os.AsyncTask$2.call(AsyncTask.java:287)
 java.util.concurrent.FutureTask.run(FutureTask.java:234)
 android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
 java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
 java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
 java.lang.Thread.run(Thread.java:856)
 threadid=14: thread exiting with uncaught exception (group=0x40a71930)

I found the issue about recycling connections bug in httpsurlconnection and possible solution :

if (Build.VERSION.SDK != null && Build.VERSION.SDK_INT > 13) {
   conn.setRequestProperty("Connection", "close");
}

But it isn't work for me.

Gather

Answer 1

Try to change your code like this:

    conn.setRequestProperty("Content-Type",
                            "application/x-www-form-urlencoded; charset: UTF-8");
    byte[] output = data.getBytes("UTF-8");
    conn.setFixedLengthStreamingMode(output.length);

    os = conn.getOutputStream();
    os.write(output);
    os.flush();
    os.close();

    DisplayResponseHeaders(conn);

    if (conn.getResponseCode() == 200) { // or other 2xx code like 204

        s = readStream(conn.getInputStream());
        Log.d("body", s);
    }
    else {

        // handle error conditions like 404, 400, 500, ...

        // now it may be necessary to read the error stream

        InputStream errorStream = conn.getErrorStream();

        // ...
    }

AFAIK you should always close all streams you opened. I'm not sure whether conn.disconnect() is doing that for you.

If you want to code your HTTP(S) requests more conveniently, you can have a look at DavidWebb where you have a list of libraries helping you to avoid using cumbersome HttpURLConnection.

Ilk

Answer 2

That EOFException suggests the response is malformed - perhaps lacking a blank line after the headers. Some HTTP client code is more forgiving in that case, for me iOS could handle my server responses fine but I was getting EOFException on Android using HttpURLConnection.

My server was using python SimpleHTTPServer and I was wrongly assuming all I needed to do to indicate success was the following:

self.send_response(200)

That sends the initial response header line, a server and a date header, but leaves the stream in the state where you are able to send additional headers too. HTTP requires an additional new line after headers to indicate they are finished. It appears if this new line isn't present when you attempt to get the result body InputStream or response code etc with HttpURLConnection then it throws the EOFException (which is actually reasonable, thinking about it). Some HTTP clients did accept the short response and reported the success result code which lead to me perhaps unfairly pointing the finger at HttpURLConnection.

I changed my server to do this instead:

self.send_response(200)
self.send_header("Content-Length", "0")
self.end_headers()

No more EOFException with that code. It's possible the "Connection: close" solutions trigger some behaviour on certain servers that might work around this (eg ensuring the response is valid before closing) but that wasn't the case with the python SimpleHTTPServer, and the root cause turned out to be my fault.

NB: There are some bugs on Android pre-Froyo (2.2) relating to keep-alive connections - see the blog post here: http://android-developers.blogspot.co.uk/2011/09/androids-http-clients.html. I'm yet to see convincing evidence of bugs with newer versions of Android.

Gemmule