Question

Write a Java program that reads words from a text file and displays all the words (duplicates allowed) in ascending alphabetical order. The words must start with a letter.
1. You must use one of following Concrete class to store data from the input.txt file.

Vector, Stack, ArrayList, LinkedList

2. To sort those words, you should use one of existing interface methods available in Collection or List class.

Answer 1

import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;

public class SortWords {

        public static void main(String[] args) throws IOException  {
                Scanner sc = new Scanner(System.in);
                BufferedReader br=null;
                List<String>words=new ArrayList<>();
                //handling with try catch for FileNotFound
                try {
                        br = new BufferedReader(new FileReader(new File("input.txt")));
                } catch (FileNotFoundException e) {
                        sc.close();
                        return;
                }
                //reading line by line
                String line = br.readLine();
                while (line != null) {
                        String arr[]=line.split(" ");
                        for(String word:arr) {
                                if(word.trim().length()!=0 && Character.isLetter(word.charAt(0))) {
                                        words.add(word);
                                }
                        }
                        line=br.readLine();
                }
                sc.close();
                br.close();
                Collections.sort(words);
                for(String s:words)
                        System.out.println(s);
        }

}

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