What does file:///android_asset/www/index.html mean?
If someone uses AndroidStudio make sure that the assets folder is placed in
app/src/main/assets
directory.
file:/// is a URI (Uniform Resource Identifier) that simply distinguishes from the standard URI that we all know of too well - http://.
It does imply an absolute path name pointing to the root directory in any environment, but in the context of Android, it's a convention to tell the Android run-time to say "Here, the directory www has a file called index.html located in the assets folder in the root of the project".
That is how assets are loaded at runtime, for example, a WebView widget would know exactly where to load the embedded resource file by specifying the file:/// URI.
Consider the code example:
WebView webViewer = (WebView) findViewById(R.id.webViewer);
webView.loadUrl("file:///android_asset/www/index.html");
A very easy mistake to make here is this, some would infer it to as file:///android_assets, notice the plural of assets in the URI and wonder why the embedded resource is not working!