I have associated my app with txt file. So user can select a file in File explorer app and select my app to open it. In OnCreate: Intent intent = getIntent(); String action = intent.getAction(); if (action != null && action.equals(Intent.ACTION_VIEW)) { txtFilePath = intent.getData().getPath(); } However, when user did not close my app, and he goes back to file explorer and open another file, OnCreate is not called. OnResusme is called instead. I put below code in OnResume: Intent intent = getIntent(); String action = intent.getAction(); if (action != null && action.equals(Intent.MAIN)) { txtFilePath = intent.getData().getPath(); } However, txtFilePath is null. Why? Thank a lot for help.