Public class CountLines(){
    try{
        BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
        System.out.println("Vennligst skriv inn filnavnet og -pathen du vil lagre infoen i:");
        String str = bf.readLine();
        File fil = new File(str);
        if (fil.exists()){
            FileReader fr = new FileReader(fil);
            LineNumberReader ln = new LineNumberReader(fr);
            int antall = 0;
            while (ln.readLine() != null){
                antall++;
            }
            return antall;
        }
        else{
            System.out.println("File does not exists!");
        }
    }
    catch(IOException e){
        e.printStackTrace();
    }

}
ID=CountLines();