Serve static directory error: given path is not a directory

[tlkahn]

I can't make nanohttpd work. It seems not be able to find the www directory in app's root.

My code is at https://github.com/tlkahn/neonx

When I tried to visit localhost:3000, I got the error: given path is not a directory. The error seems to come from this line: https://git.io/fjS3f

I guess the way I initialize the rootDir is wrong (this line: https://git.io/fjS3v). But how can I make this work? I mean to serve the whole directory, which means all CSS/JS/hypyerlinks should work, once nanohttpd starts serving...

My code at MainActivity.java:

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        BottomNavigationView navView = findViewById(R.id.nav_view);
        mWebView = findViewById(R.id.webkit);
        navView.setOnNavigationItemSelectedListener(mOnNavigationItemSelectedListener);
        WebSettings webSettings = mWebView.getSettings();
        webSettings.setMixedContentMode(WebSettings.MIXED_CONTENT_ALWAYS_ALLOW);
        webSettings.setDomStorageEnabled(true);
        mWebView.getSettings().setLoadsImagesAutomatically(true);
        mWebView.getSettings().setJavaScriptEnabled(true);
        mWebView.setScrollBarStyle(View.SCROLLBARS_INSIDE_OVERLAY);
        mWebView.setWebViewClient(new WebViewClient() {
            @Override
            public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request) {
                return false;
            }
        });
        if (!haveNetworkConnection()) {
            new AlertDialog.Builder(this)
                .setTitle("You are not connected to internet.")
                .setMessage("Are you sure you want to exit?")
                .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        finishAffinity();
                        System.exit(0);
                    }
                }).setNegativeButton("No", null).show();
        }
        startLocalServer(3000, "www", true, true );
    }

  public void startLocalServer(int port, String root, Boolean localhost, Boolean keepAlive) {
      try {
          File www_root = new File(root);
          server = new WebServer("localhost", port, www_root.getAbsoluteFile());
          server.start();
          printIp();
      } catch (IOException e) {
          e.printStackTrace();
      }
  }

[tlkahn]

Not nanohttpd issue.