Unable to get DeclaredField "usr_paths " via java reflection 17.0.3

Hello to everyone sitting on this forum, enter code hereI ran into a problem, I will be very glad if you can help me.

So I'm trying to get usr_paths, but the console gives an error that it can't find this field, what should I do?

public static void addDir(String s) throws IOException {
    try {
        Field field = ClassLoader.class.getDeclaredField("usr_paths"); // there's a error here !!
        field.setAccessible(true);
        String[] paths = (String[]) field.get(null);
        for (int i = 0; i < paths.length; i++) {
            if (s.equals(paths[i])) {
                return;
            }
        }
        String[] tmp = new String[paths.length + 1];
        System.arraycopy(paths, 0, tmp, 0, paths.length);
        tmp[paths.length] = s;
        field.set(null, tmp);
        System.setProperty("java.library.path", System.getProperty("java.library.path") + File.pathSeparator + s);
    } catch (IllegalAccessException e) {
        throw new IOException("Failed to get permissions to set library path");
    } catch (NoSuchFieldException e) {
        throw new IOException("Failed to get field handle to set library path");
    }
}