Android widget read openFileInput

Question

so I'm kinda new to all of this application making.

I'm trying to reach a file using the command InputStream inputStream = openFileInput("files.txt"); and it gives me the error "Cannot resolve methodopenFileInput(java.lang.String)".My file is not saved i assets or in resources, it's saved i whatever place it saves when you just create it in the application.

Questions

1. Can I read a file in widgets
2. If so why is this not working?

The function

private void readFiles() throws IOException 
{
    cards.removeAll(cards);
    InputStream inputStream = openFileInput("files.txt");
    if(inputStream != null){
        InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
        BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
        int size = Integer.parseInt(bufferedReader.readLine());
        for(int i = 0; i < size; i++){
            card tmp = new card();
            tmp.setAlias(bufferedReader.readLine());
            tmp.setIconID(Integer.parseInt(bufferedReader.readLine()));
            tmp.setId(bufferedReader.readLine());
            tmp.setRemaining(Integer.parseInt(bufferedReader.readLine()));
            tmp.setDescription(bufferedReader.readLine());
            tmp.setPeriodStartDate(bufferedReader.readLine());
            tmp.setPeriodEndDate(bufferedReader.readLine());
            tmp.setPeriodRemaining(Integer.parseInt(bufferedReader.readLine()));
            tmp.setWaitingPeriods(Integer.parseInt(bufferedReader.readLine()));
            tmp.setUnFetched(Integer.parseInt(bufferedReader.readLine()));
            tmp.setNameDescription(bufferedReader.readLine());
            tmp.setCardExpiryDate(bufferedReader.readLine());
            tmp.setCardStatus(bufferedReader.readLine());
            tmp.setDaysUntilCardExpiry(bufferedReader.readLine());
            cards.add(tmp);
        }
        inputStream.close();
    }
}