public static void count() throws IOException {
        Properties prop = new Properties();

        File file = new File("app.ini");

        if (!file.exists())
            file.createNewFile();

        prop.load(new BufferedReader(new FileReader(file)));

        int count = 0;
        String appRunCount = prop.getProperty("appruncount");
        if (appRunCount != null) {
            count = Integer.parseInt(appRunCount);
            if (count >= 5) {
                System.out.println("试用次数超过限制，请注册后使用");
                return;
            }
        }
        count++;

        prop.setProperty("appruncount", count + "");
        prop.store(new BufferedWriter(new FileWriter(file)), "");
    }