OutOfMemoryException when using Gson streaming JsonReader in Android

Question

I previously was trying this using a tree structure. The JSON response is about 3.5MB, so it was understandable that trying to parse it this way would cause older devices to run out of memory.

My question is: Why, after I have switched to a streaming JsonReader, am I still getting the OutOfMemoryException? I even save the response to a .json file on the sd card and read from there so that the String doesn't need to be stored in memory.

  List<CurrencyPair> currencyPairs = new ArrayList<CurrencyPair>();
  URL url = new URL("http://pubapi.cryptsy.com/api.php?method=orderdatav2");

  File sdCard = Environment.getExternalStorageDirectory();
  File directory = new File(sdCard.getAbsolutePath() + "/zTrader");
  directory.mkdirs();
  File file = new File(directory, "cryptsy_response.json");

  BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream()));
  BufferedWriter out = new BufferedWriter(new FileWriter(file));

  char[] cbuf = new char[255];
  while ((in.read(cbuf)) != -1) {
    out.write(cbuf);
  }
  in.close();
  out.close();

  FileInputStream fis = new FileInputStream(file);
  InputStreamReader fileInputStreamReader = new InputStreamReader(fis);
  Reader bufferedReader = new BufferedReader(fileInputStreamReader);
  JsonReader reader = new JsonReader(bufferedReader);

  reader.beginObject();
  Map<CurrencyPair, Integer> currencyPairs_MarketIds = new HashMap<CurrencyPair, Integer>();

  while (reader.hasNext()) {

    String name = reader.nextName();

    if (name.equals("success")) {
      reader.nextInt();
    }
    else if (name.equals("return")) {
      reader.beginObject();

      while (reader.hasNext()) {
        String pairString = reader.nextName();
        String[] currencies = pairString.split("/");
        CurrencyPair currencyPair = new CurrencyPair(currencies[0], currencies[1]);
        currencyPairs.add(currencyPair);

        reader.beginObject();
        while (reader.hasNext()) {
          if (reader.nextName().equals("marketid")) {
            Integer id = Integer.valueOf(reader.nextString());
            currencyPairs_MarketIds.put(currencyPair, id);
          }
          else {
            reader.skipValue();
          }
          if (sleep)
            Thread.sleep(25);
        }
        reader.endObject();
        if (sleep)
          Thread.sleep(25);
      }
    }
  }
  reader.close();
  file.delete();