package copyfile;

/*
 * This program accepts two filenames either at
 * the command-line or in the source code itself.
 *
 * To use this program in the command-line:
 *
 * java CopyFile filename1 filename2
 *
 * Otherwise, just type in the path to both filenames
 * in the source code.
 *
 * If the second file does not exist,
 * the program will create the file.
 */

import java.io.*;

// Copies a file to another file.
class CopyFile {
    public static void main(String args[]) {
        String first;
        String second;
        String line;

        // Sets first and second using either command-line or source code
        if(args.length == 2) {
            first = args[0];
            second = args[1];
        } else {
            first = "src/copyfile/first.txt";
            second = "src/copyfile/second.txt";
        }

        // Tries to read and write from first to second.
        try(BufferedReader br = new BufferedReader(
                new FileReader(first));
            FileWriter fw = new FileWriter(second)) {

            do {
                line = br.readLine();

                if(line != null) {
                    fw.write(line);
                }
            } while(line != null);
        } catch(FileNotFoundException exc) {
            System.out.println("FileNotFound Exception: File not found!");
            return;
        } catch(IOException exc) {
            System.out.println("I/O Exception: " + exc);
            return;
        }

        System.out.println("Successfully copied file!");
    }
}