Question

I have an AsyncTask in my application that creates a HttpURLConnection. Next, it calls getOutputStream(), writes some bytes, flushes and closes. Then it calls getResponseCode(), and getInputStream(). If I need to post code, I can, but thought I’d keep the question small.

When I run this the first time, I get a 200 response code, and I get the correct input stream.

When I run this a second to fifth time, I get a new thread (viewable in the DDMS view), and I receive a 500 response code, and an IOException when getting the input stream.

When I call this a sixth time or more, no new threads are created, and I still get the 500 response code and the IOException.

What can I look for here? It always works one time and never again. Has anyone else seen this? I’m completely stumped.

Here’s MINIMAL code (I removed try/catch, variable declarations, app specific stuff, etc):

   protected String doInBackground(String... params)
   {
     connectURL = new URL(sWebPath);
     conn = (HttpURLConnection)connectURL.openConnection();

     conn.setDoInput(true);
     conn.setDoOutput(true);
     conn.setUseCaches(false);
     conn.setConnectTimeout(10000);

     conn.setRequestMethod("POST");

     conn.setRequestProperty("User-Agent", "MyAppAgent");
     conn.setRequestProperty("Connection", "Keep-Alive");
     conn.setRequestProperty("Content-Type", "application/soap+xml; charset=utf-8");

     // Setup my post as a string s.

     conn.setRequestProperty("Content-Length", String.valueOf(s.length()));

     conn.connect();
     DataOutputStream dataStream = new DataOutputStream(conn.getOutputStream());
     dataStream.writeBytes(s);

     dataStream.flush();
     dataStream.close();
     dataStream = null;

     // 200 1st time only, 500 after that.
     responseCode = conn.getResponseCode();

     // Works 1st time only, IO error after that
     DataInputStream dis = new DataInputStream(conn.getInputStream());
     byte[] data = new byte[16384];
     int len = dis.read(data, 0, 16384);

     dis.close();
     conn.disconnect();

     response = new String(data, 0, len);

     // do whatever with my response
  }

  @Override
  protected void onPostExecute(String result)
  {
     super.onPostExecute(result);

     // Now I call a Toast message on the original context used to 
     // create this AsyncTask.
  } 

  // The onClickListener of a button calls this AsyncTask (TierRequest class) with only two lines
  TierRequest t = new TierRequest(WhateverMyCurrentActivityIs.this);
  t.execute(A_Constant_Indicating_The_Type_Of_Post);

Answer 1

This really feels like a problem on the server (code 500 is almost universally used to indicate some sort of problem in the server side code, although it could be a problem with the web server itself).

Do you control the server code? Are you possibly opening a file and not closing it, so that additional calls may run into “access denied” or “file already open” errors?