Calling ext.js files under /resource/app directory

This is my folder structure for a spring mvc project

The app.js file is called from the index.jsp file as the above.

This is app.js file.

This is application.js file under /resource/app folder.

To make sure, I also added another resource handler to spring mvc config.!

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Somehow it can see the Application.js file under the app folder, but it failed to find any other files below the app folder....

Do you have any idea what the problem is and how I can solve this one?