Question

Write a Java program that reads words from a text file and displays all the non-duplicate words in ascending order. The text file is passed as a command-line argument.

Command line argument: test2001.txt

Correct output:

Words in ascending order...

1mango

Salami

apple

banana

boat

zebra

Answer 1

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

public class WordsInFile {

    public static void main(String[] args) {
        if (args.length > 0) {
            File file = new File(args[0]);
            try {
                Scanner fin = new Scanner(file);
                Set<String> words = new TreeSet<>();
                while (fin.hasNext()) {
                    words.add(fin.next());
                }
                System.out.println("Words in ascending order...");
                for (String word : words) {
                    System.out.println(word);
                }
                fin.close();
            } catch (FileNotFoundException e) {
                System.out.println(file.getAbsolutePath() + " is not found!");
            }
        } else {
            System.out.println("Please provide filename as command line argument");
        }
    }
}