quest1.java

import java.io.File;
import java.util.Scanner;
import java.util.ArrayList;
public class quest1 {

    public static void main(String[] args){
        
        ArrayList<String> words = new ArrayList<>();
        try {
            System.out.print("Enter the file name with extension e.g. file.txt: ");
            
            Scanner input = new Scanner(System.in);
            
            String fileName = input.nextLine();
            File file = new File(fileName);

            System.out.print("Enter the word you're looking for: ");

            String word = input.nextLine();    

            input = new Scanner(file);
            while (input.hasNext()) {
                String line = input.next();
                //System.out.println(line);
                words.add(line);
            }
            input.close();
            print("File contains " + words.size() + " words.");

            ArrayList<Integer> position = new ArrayList();
            int wordCount = 0;

            for (int i = 0; i < words.size(); i++){
                String currentWord = words.get(i);
                if (currentWord.trim().equalsIgnoreCase(word.trim())){
                    wordCount += 1;
                    position.add(i + 1);
                }

            }            

            print("Word " + word + " occurs " + wordCount + " times in " + fileName);
            if (wordCount > 0){
                print("at position(s) " + convertPositionsToPrintableString(position));
            }

        } catch (Exception ex) {
            ex.printStackTrace();
            print(ex.getMessage());
        }

    }

    public static String convertPositionsToPrintableString(ArrayList<Integer> position){
        
        String positions = "";

        for (int j = 0; j < position.size(); j++){
            positions += position.get(j) + " ";
        }

        return positions;
    }

    public static void print(String text){
        System.out.println(text);
    }

}