title: HTTPURLConnection - POST multipart/form-data with large file with FixedLengthStreamingMode
body: <p>So I'm trying to send a multipart/form-data POST request with large image file. I can't pre-convert file to byte array, my app will crash with OutOfMemory exception, so I have to write contents of the file directly to connection's outputstream. Also, my server doesn't support chunked mode, so I have to calculate content length before sending data and use connection's setFixedLengthStreamingMode. </p>
  
  <pre><code>public void createImagePostWithToken(String accessToken, String text,
          String type, String imagePath) {
  
      URL imageUrl = null;
      String lineEnd = "\r\n";
      String twoHyphens = "--";
  
      // generating byte[] boundary here
  
      HttpURLConnection conn = null;
      DataOutputStream outputStream = null;
      DataInputStream inputStream = null; 
  
      int bytesRead, bytesAvailable, bufferSize;
      byte[] buffer;
      int maxBufferSize = 1*1024*1024;
  
      try
      {
          long contentLength;
          int serverResponseCode;
          String serverResponseMessage;
          File file = new File(imagePath);            
          FileInputStream fileInputStream = new FileInputStream(file);
          imageUrl = buildUri("posts").toURL();
          conn = (HttpURLConnection)imageUrl.openConnection();
          conn.setConnectTimeout(30000);
          conn.setReadTimeout(30000);
          conn.setDoOutput(true);
          conn.setDoInput(true);         
          conn.setRequestMethod("POST");
          conn.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + boundary);            
  
          String stringForLength = new String();  
  
          stringForLength += "Content-Type: multipart/form-data;boundary=" + boundary;
  
          stringForLength += twoHyphens + boundary + lineEnd + "Content-Disposition: form-data; name=\"access_token\"" + lineEnd;
          stringForLength += "Content-Type: text/plain;charset=UTF-8" + lineEnd + "Content-Length: " + accessToken.length() + lineEnd + lineEnd;
          stringForLength += accessToken + lineEnd + twoHyphens + boundary + lineEnd;
  
          stringForLength += "Content-Disposition: form-data; name=\"text\"" + lineEnd;
          stringForLength += "Content-Type: text/plain;charset=UTF-8" + lineEnd + "Content-Length: " + text.length() + lineEnd + lineEnd;
          stringForLength += text + lineEnd + twoHyphens + boundary + lineEnd;
  
          stringForLength += "Content-Disposition: form-data; name=\"type\"" + lineEnd;
          stringForLength += "Content-Type: text/plain;charset=UTF-8" + lineEnd + "Content-Length: " + type.length() + lineEnd + lineEnd;
          stringForLength += type + lineEnd + twoHyphens + boundary + lineEnd;
  
          stringForLength += twoHyphens + boundary + lineEnd + "Content-Disposition: form-data; name=\"image\"" + lineEnd;
          stringForLength += "Content-Type: application/octet-stream" + lineEnd + "Content-Length: " + file.length() + lineEnd + lineEnd;
          stringForLength += lineEnd + twoHyphens + boundary + twoHyphens + lineEnd;
  
          int totalLength = stringForLength.length() + (int)file.length();           
          conn.setFixedLengthStreamingMode(totalLength); 
  
  
          outputStream = new DataOutputStream( conn.getOutputStream() );          
          outputStream.writeBytes(twoHyphens + boundary + lineEnd);
  
          // access token 
  
          outputStream.writeBytes("Content-Disposition: form-data; name=\"access_token\"" + lineEnd);
          outputStream.writeBytes("Content-Type: text/plain;charset=UTF-8" + lineEnd);
          outputStream.writeBytes("Content-Length: " + accessToken.length() + lineEnd);
          outputStream.writeBytes(lineEnd);
          outputStream.writeBytes(accessToken + lineEnd);
          outputStream.writeBytes(twoHyphens + boundary + lineEnd);
  
          // text 
  
          outputStream.writeBytes("Content-Disposition: form-data; name=\"text\"" + lineEnd);
          outputStream.writeBytes("Content-Type: text/plain;charset=UTF-8" + lineEnd);
          outputStream.writeBytes("Content-Length: " + text.length() + lineEnd);
          outputStream.writeBytes(lineEnd);
          outputStream.writeBytes(text + lineEnd);
          outputStream.writeBytes(twoHyphens + boundary + lineEnd);
  
          // type 
  
          outputStream.writeBytes("Content-Disposition: form-data; name=\"type\"" + lineEnd);
          outputStream.writeBytes("Content-Type: text/plain;charset=UTF-8" + lineEnd);
          outputStream.writeBytes("Content-Length: " + type.length() + lineEnd);
          outputStream.writeBytes(lineEnd);
          outputStream.writeBytes(type + lineEnd);
          outputStream.writeBytes(twoHyphens + boundary + lineEnd);
  
          // image
  
          outputStream.writeBytes(twoHyphens + boundary + lineEnd);
          outputStream.writeBytes("Content-Disposition: form-data; name=\"image\"" + lineEnd);
          //outputStream.writeBytes(lineEnd);
          outputStream.writeBytes("Content-Type: application/octet-stream" + lineEnd);
          outputStream.writeBytes("Content-Length: " + file.length() + lineEnd);
          outputStream.writeBytes(lineEnd);           
  
          bytesAvailable = fileInputStream.available();
          bufferSize = Math.min(bytesAvailable, maxBufferSize);
          buffer = new byte[bufferSize];
          // Read file
          bytesRead = fileInputStream.read(buffer, 0, bufferSize);
  
          while (bytesRead &gt; 0)
          {
          outputStream.write(buffer, 0, bufferSize);          
          bytesAvailable = fileInputStream.available();
          bufferSize = Math.min(bytesAvailable, maxBufferSize);
          bytesRead = fileInputStream.read(buffer, 0, bufferSize);
          }
  
          outputStream.writeBytes(lineEnd);
          outputStream.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);
  
          Log.d("posttemplate", "connection outputstream size is " + outputStream.size());
  
          // finished with POST request body
  
  
       // Responses from the server (code and message)
          serverResponseCode = conn.getResponseCode();
          serverResponseMessage = conn.getResponseMessage();
  
          Log.d("posttemplate", "server response code "+ serverResponseCode);
          Log.d("posttemplate", "server response message "+ serverResponseMessage);
  
          fileInputStream.close();
          conn.disconnect();
          outputStream.flush();
          outputStream.close();
  
  
      } catch (MalformedURLException e)
      {
          Log.d("posttemplate", "malformed url", e);
          //TODO: catch exception;
      } catch (IOException e)
      {
          Log.d("posttemplate", "ioexception", e);
          //TODO: catch exception
      }        
  
  }
  </code></pre>
  
  <p>Unfortunately, my app crashes with IOException at outputStream.close(), and I have no idea why:</p>
  
  <pre><code>03-16 13:56:51.035: D/posttemplate(6479): java.io.IOException: unexpected end of stream
  03-16 13:56:51.035: D/posttemplate(6479):   at org.apache.harmony.luni.internal.net.www.protocol.http.FixedLengthOutputStream.close(FixedLengthOutputStream.java:57)
  03-16 13:56:51.035: D/posttemplate(6479):   at java.io.FilterOutputStream.close(FilterOutputStream.java:66)
  03-16 13:56:51.035: D/posttemplate(6479):   at com.futubra.api.impl.PostTemplate.createImagePostWithToken(PostTemplate.java:282)
  03-16 13:56:51.035: D/posttemplate(6479):   at com.futubra.FutubraNewPostActivity.createPost(FutubraNewPostActivity.java:128)
  03-16 13:56:51.035: D/posttemplate(6479):   at com.futubra.FutubraNewPostActivity_.access$2(FutubraNewPostActivity_.java:1)
  03-16 13:56:51.035: D/posttemplate(6479):   at com.futubra.FutubraNewPostActivity_$5.run(FutubraNewPostActivity_.java:141)
  03-16 13:56:51.035: D/posttemplate(6479):   at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088)
  03-16 13:56:51.035: D/posttemplate(6479):   at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581)
  03-16 13:56:51.035: D/posttemplate(6479):   at java.lang.Thread.run(Thread.java:1019)
  </code></pre>