Android webview, loading javascript file in assets folder

Question

I\'ve seen this question has been asked a lot of times, but still can\'t manage to get my code working.

I want my webview to load some URL (say www.google.c

Answer 1

With the following two conditions given:

• minSdkVersion 21
• targetSdkVersion 28

I am able to successfully load any local asset (js, png, css) via the following Java code

@Override
public WebResourceResponse shouldInterceptRequest(WebView view, WebResourceRequest request) {
    Uri uri = request.getUrl();
    if (uri.getHost().equals("assets")) {
        try {
            return new WebResourceResponse(
                URLConnection.guessContentTypeFromName(uri.getPath()),
                "utf-8",
                MainActivity.this.getAssets().open(uri.toString().substring(15)));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    return null;
}

And in the HTML code I can use

In Java the following then also works (you'd also need to add a favicon.ico to the assets)

webView.loadUrl("https://assets/example.html");

Using https:// as the scheme allows me to load local assets from a page served via HTTPS without security issues due to mixed-content.

None of these require to be set:

webSettings.setMixedContentMode(WebSettings.MIXED_CONTENT_ALWAYS_ALLOW);
webSettings.setDomStorageEnabled(true);
webSettings.setAllowContentAccess(true);
webSettings.setAllowFileAccess(true);
webSettings.setAllowFileAccessFromFileURLs(true);
webSettings.setAllowUniversalAccessFromFileURLs(true);