Question

2. Create a java program that reads a file line by line and extract the first word.       

The program will ask for the name of input and output file.

Input file: words.txt

today tomorrow

sam peterson

peter small

roy pratt

Output file: outwords.txt

tomorrow

peterson

small

pratt

Answer 1

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

public class ExtractFirstWord {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        System.out.print("Enter input file name: ");
        File file = new File(in.nextLine());
        try {
            Scanner fin = new Scanner(file);
            System.out.print("Enter output file name: ");
            PrintWriter pw = new PrintWriter(in.nextLine());
            String line, words[];
            while (fin.hasNextLine()) {
                line = fin.nextLine();
                words = line.split(" ");
                if (words.length > 1)
                    pw.println(words[1]);
            }
            pw.close();
            fin.close();
        } catch (FileNotFoundException e) {
            System.out.println(file.getAbsolutePath() + " does not exists!");
        }
    }
}