Question

Hi need help writing a method in java:

It should accept a file name as a parameter, and then open the file and return how many unique words there are in the file (ignore capitalization). If possible can you show how to use a TreeSet as a storage to put in the unique words and then return its size.

Answer 1

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;
import java.util.TreeSet;

public class NumberOfUniqueWords {

    public static int countUniqueWords(String filename) {
        TreeSet<String> set = new TreeSet<>();
        File file = new File(filename);
        try {
            Scanner fin = new Scanner(file);
            while (fin.hasNext()) {
                set.add(fin.next().toLowerCase());
            }
            fin.close();
        } catch (FileNotFoundException e) {
            System.out.println(file.getAbsolutePath() + " is not found!");
        }
        return set.size();
    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        System.out.print("Enter file name: ");
        System.out.println("Number of words in file is " + countUniqueWords(in.nextLine()));
    }
}