title: how to write bytes in a file without overwriting it
body: <p>i am getting chunks of bytes from server and i need to write them in a file without overwriting the old chunk. how can i do that? 
  i am doing it this way..</p>
  
  <pre><code>private void createMapFile(String fileName, byte mapBytes[]) throws IOException
      {       
          File filePath = new File(Environment.getExternalStorageDirectory()+"/map/"+fileName);
  
          PrintWriter pw = new PrintWriter(new FileOutputStream(filePath, true));  
          pw.print(mapBytes);  
          pw.flush();  
          pw.close(); }
  </code></pre>
  
  <p>my this method takes the file name and chunk of bytes as argument. anytime i get new chunk from server this method gets called. by this method i cannot write the all chunks in a file.</p>
  
  <p>any help will be appreciative.
  thanks</p>