Java 自动判断配置文件是否已经存在，如果不存在自动创建，如果存在直接读写

try {
    pro.load(new BufferedInputStream(new FileInputStream("config.ini")));
} catch (FileNotFoundException e) {
    pro.put("GuestDefaultFloor", "10");
    try {
        pro.store(new BufferedOutputStream(new FileOutputStream("config.ini")),"Save Configs File.");
    } catch (FileNotFoundException f) {
        f.printStackTrace();
    } catch (IOException i) {
        i.printStackTrace();
    }
} catch (IOException i) {
    i.printStackTrace();
} finally {
    String defaultGuestFloor = pro.getProperty("GuestDefaultFloor");
    guestFloor = Integer.parseInt(defaultGuestFloor);
}