Android : android convert file of size > 1gb to byte array

I want convert the data to byte array. so that, i can send it over the network. For small file it is working. but for file of size>900 mb, am getting runtime exception. Here is my code.

 try {            
            ByteArrayOutputStream byteBuffer = new ByteArrayOutputStream();
            int bufferSize = 1024;
            byte[] buffer = new byte[bufferSize];
            int len = 0;
            while ((len = is.read(buffer)) != -1) {
                byteBuffer.write(buffer, 0, len);
            }
            is.close();
            return byteBuffer;
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }