How can I get a webview archive file to InputStream in android?

I asked a similar question before about the loading archive file to WebView.

According to the tutorial, I have to load the archive file to InputStream so that I can use the method loadToWebView in WebArchiveReader.java.

However, in the tutorial, the writer get the archive file by using the following statement:

InputStream is = getAssets().open("TestHtmlArchive.xml");

Unfortunately, I want to get the archive file from somewhere else other than "Assets" folder.

WebView webView = (WebView) rootView.findViewById(R.id.webview_layout);
String url = "http://www.yahoo.com";
webView.loadUrl(url);
String path = getFilesDir().getAbsolutePath() + File.separator + "yahoo" + ".html";
webView.saveWebArchive(path);
webView.loadUrl("file://" + path);

Assuming I want to load the file "yahoo.html" as I saved in the code above.

How can I get it to an instance of InputStream?

it seems the right way to open a file to InputStream is shown as follow.

            String path = getFilesDir().getAbsolutePath() + File.separator
                    + "yahoo" + ".html";

            File file = new File(path);

            try {
                InputStream is = new BufferedInputStream(new FileInputStream(file));

                WebArchiveReader wr = new WebArchiveReader() {

                    @Override
                    public void onFinished(WebView webView) {
                        System.out.println("Page loaded");
                    }
                };

                if (wr.readWebArchive(is)) {
                    wr.loadToWebView(webView);
                }

            } catch (IOException e) {
                e.printStackTrace();
            }