SImple Text I/O Program

Question

Morning,
I have gotten a new assignment which requires me to right a Text I/O program and to copy it as well. We are required to copy it using Command Line parameters I believe. Replacing the string of the text file created and copying it to a new file. So far I have the class written to write and read the file but the copying of the file does not seem to work.
Here is the code so far: import java.io.*;
import java.util.*;
public class WriteFile {
     public static void main (String []args)throws Exception {
          File text = new File("text.txt");
          if (text.exists()) {
               System.out.println("File already exists " + text.exists());
               System.exit(0);
          String [] array = {
               "Josh Harper ",
               "CS Student ",
               "January 22 1986 "
          PrintWriter output = new PrintWriter(text);
          for (int i= 0; i<3; i++) {
          output.println(array);
          output.close();
import java.io.*;
import java.util.*;
public class ReadFile {
     public static void main(String[] args) throws Exception {
          File text = new File("text.txt");
          Scanner input = new Scanner(text);
          while(input.hasNext()) {
               String fname = input.next();
               String lname = input.next();
               String degree = input.next();
               String student = input.next();
               String month = input.next();
               int date = input.nextInt();
               int year = input.nextInt();
               System.out.println(fname + " " + lname + "\n" + degree + " " + student + "\n" + month + " " + date + " " + year);
          input.close();
import java.io.*;
import java.util.*;
public class CopyText {
     public static void main (String[] args) throws Exception {
          if (args.length != 4) {
               System.out.println("Usage:java CopyText.java text.txt copy.txt PrintWriter PrintWriter");
               System.exit(0);
          File sourcefile = new File(args[0]);
          if (!sourcefile.exists()) {
               System.out.println("Source file " + args[0] + " does not exist");
               System.exit(0);
          File copyfile = new File(args[1]);
          if (copyfile.exists()) {
               System.out.println("The copy file " + args[1] + " already exists");
               System.exit(0);
          Scanner input = new Scanner(sourcefile);
          PrintWriter output = new PrintWriter(copyfile);
          while(input.hasNext()) {
               String s1 = input.nextLine();
               String s2 = s1.replaceAll(args[2], args[3]);
               output.println(s2);
          input.close();
          output.close();
Any insight on how the code for copying text by passing through as a command-line argument will be much of a great help, the book we use is very vague and the professor explanation was hard to replicate while doing my own program
Thanks in advance.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           

Answer 1

Hello,
I'm not exactly sure of what your problem but if you just want to copy files, whether they are plain text or other, you can just use the good old method which copy byte by byte your file
public static void copyFile(File in, File out) throws Exception {
    FileInputStream fis  = new FileInputStream(in);
    FileOutputStream fos = new FileOutputStream(out);
    try {
        byte[] buf = new byte[1024];
        int i = fis.read(buf);
        while (i  != -1) {
            fos.write(buf, 0, i);
            i = fis.read(buf);
    catch (Exception e) {
        throw e;
    finally {
        if (fis != null) fis.close();
        if (fos != null) fos.close();
  }You can also, if you want to go deeper, check at the java API for java.nio.channels for faster copy but I'm not a huge fan of it.