サーバーからのレスポンスデータが多いとエラーになる

HttpPostFailure.java

public JSONObject post(String urlString) throws Exception{
    URL url = new URL(urlString);

    HttpsURLConnection con = (HttpsURLConnection) url.openConnection();
    con.setConnectTimeout(Const.HTTP_CONNECT_TIMEOUT);
    con.setReadTimeout(Const.HTTP_READ_TIMEOUT);
    con.setUseCaches(false);
    con.setDoInput(true);
    con.setDoOutput(true);
    con.setChunkedStreamingMode(0);
    con.connect();

    OutputStream out = con.getOutputStream();
    out.write( this.values.getBytes("UTF-8") );
    out.flush();
    out.close();

    final int status = con.getResponseCode();

    if (status != HttpURLConnection.HTTP_OK) {
        con.disconnect();
        throw new Exception("通信に失敗しました\nお手数ですが、しばらくしてから再度お試し下さい");
    }

    BufferedReader reader = new BufferedReader(
        new InputStreamReader(con.getInputStream())
    );

    //(1)コネクション切断 
    con.disconnect();

    StringBuilder builder = new StringBuilder();
    String body;
    while ((body = reader.readLine()) != null) {
        builder.append(body);
    }

    //(2)コネクション切断
    //con.disconnect();

    String jsonData = builder.toString();
    return new JSONObject(jsonData);
}