What does file:///android_asset/www/index.html mean?

Question

I want to know what does file:/// mean while loading a html file from the assets folder in android

Is it an absolute path name which points to the root directory?

I saw this in the tutorial for phonegap by the way.

Better question: Where does `file:///android_assets/` point to in project structure? — Monday Fatigue, Nov 22 '16 at 18:29

score 42 · Accepted Answer · answered Aug 14 '12 at 23:08

42

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!

answered Aug 14 '12 at 23:08

t0mm13b

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"asset" verses "assets" was an error that took me hours to solve on my first PhoneGap/Android project. Your solution helped me realize what I was doing wrong. – Brian Stinar Jul 15 '13 at 00:18
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Do I have to create this folder or where exactly is localize? – ncubica Feb 12 '14 at 23:36
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You create that in `/res` a folder called `assets`. – t0mm13b Feb 13 '14 at 20:30
Why does it use three slashes? – Michael Levy Apr 20 '15 at 23:34
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@MichaelLevy see http://tools.ietf.org/html/draft-kerwin-file-scheme-06 on Page 4 for your answer. It is a widely adopted de-facto standard for Uri naming conventions in regards to filesystems. Also, see http://superuser.com/questions/352133/why-do-file-urls-start-with-3-slashes as well. – t0mm13b Apr 20 '15 at 23:58
So is the directory structure in this case /res/assets/android_asset/www/index.html then? @t0mm13b – Paradox May 01 '18 at 15:02

score 18 · Answer 2 · edited Jun 20 '20 at 09:12

18

If someone uses AndroidStudio make sure that the assets folder is placed in

app/src/main/assets

directory.

edited Jun 20 '20 at 09:12

Community

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answered Sep 02 '14 at 21:08

Lunero

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What about for `androidTest` instrumented tests? – IgorGanapolsky Oct 18 '20 at 18:02

score 17 · Answer 3 · answered Apr 12 '16 at 19:21

The URI "file:///android_asset/" points to YourProject/app/src/main/assets/.

Note: android_asset/ uses the singular (asset) and src/main/assets uses the plural (assets).

Suppose you have a file YourProject/app/src/main/assets/web_thing.html that you would like to display in a WebView. You can refer to it like this:

WebView webViewer = (WebView) findViewById(R.id.webViewer);
webView.loadUrl("file:///android_asset/web_thing.html");

The snippet above could be located in your Activity class, possibly in the onCreate method.

Here is a guide to the overall directory structure of an android project, that helped me figure out this answer.

score 4 · Answer 4 · edited Oct 29 '20 at 12:42

4

It is actually called file:///android_asset/index.html

file:///android_assets/index.html will give you a build error.

edited Oct 29 '20 at 12:42

grg

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answered Jan 20 '14 at 19:13

sivi

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Holy correct : this answer + the previous answer of (app/src/main/assets) – Ranger Way Mar 09 '15 at 08:42

score 0 · Answer 5 · edited Apr 12 '15 at 10:42

It took me more than 4 hours to fix this problem. I followed the guide from http://docs.phonegap.com/en/2.1.0/guide_getting-started_android_index.md.html#Getting%20Started%20with%20Android

I'm using Android Studio (Eclipse with ADT could not work properly because of the build problem).

Solution that worked for me:

I put the /assets/www/index.html under app/src/main/assets directory. (take care AndroidStudio has different perspectives like Project or Android)
use super.loadUrl("file:///android_asset/www/index.html"); instead of super.loadUrl("file:///android_assets/www/index.html"); (no s)

score 0 · Answer 6 · edited Mar 09 '17 at 03:01

0

it's file:///android_asset/... not file:///android_assets/... notice the plural of assets is wrong even if your file name is assets

edited Mar 09 '17 at 03:01

Micho

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answered Mar 08 '17 at 19:33

Mahmoud Abdelwahab

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Duplicate of answer provided 3 years prior: https://stackoverflow.com/a/21242233/1549818 – grg Oct 29 '20 at 12:41

What does file:///android_asset/www/index.html mean?

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