Inject javascript file to my site with webview in android

Question

I want to inject javascript file to my site. My site is a simple html page that is on server. I have injected css file. (with Manish\'

Answer 1

Some refinements to previous answer. Suppose we use Cyrillic words. Result would be a garbaged strings. It's not good. With code below you can use non-english chars in content. Just add additional url-encoding/decoding to your code and you good to go. Reedited version below.

private void injectJS() {
    try {
        InputStream inputStream = getAssets().open("jscript.js");
        byte[] buffer = new byte[inputStream.available()];
        inputStream.read(buffer);
        inputStream.close();

        // preserve non-english letters
        String uriEncoded = URLEncoder.encode(new String(buffer, "UTF-8"), "UTF-8").replace("+", "%20");

        String encoded = Base64.encodeToString(uriEncoded.getBytes(), Base64.NO_WRAP);
        webView.loadUrl("javascript:(function() {" +
                "var parent = document.getElementsByTagName('head').item(0);" +
                "var script = document.createElement('script');" +
                "script.type = 'text/javascript';" +
                // don't forget to use decodeURIComponent after base64 decoding
                "script.innerHTML = decodeURIComponent(window.atob('" + encoded + "'));" +
                "parent.appendChild(script)" +
                "})()");
    } catch (Exception e) {
        e.printStackTrace();
    }
}