/** Copy file contents using buffering
 **/

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;

public class BufferedCopy {
  public static void main(String[] args) {
    if (args.length != 1) 
      System.out.println("usage: BufferedCopy file_to_copy");
    else {
      BufferedCopy obj = new BufferedCopy();
      try {
        obj.makeCopy(args[0]);
      }
      catch (IOException e) {
        System.out.println(e);
      }
    }
  }

  public void makeCopy(String filename) throws IOException {
    FileReader fr = new FileReader(filename);
    BufferedReader bufIn = new BufferedReader(fr);

    FileWriter fw = new FileWriter(filename + ".copy");
    BufferedWriter bufOut = new BufferedWriter(fw);

    // An alternative way to write the previous four lines is:
    // BufferedReader bufIn = new BufferedReader( new FileReader(args[0]));
    // BufferedWriter bufOut = new BufferedWriter( new FileWriter(filename + "copy));
    // since fr and fw are only used in the BufferedReader/Writer
    // constructors.  

    String s;

    // Read and write lines of text (through buffers) 
    while (true) {
      s = bufIn.readLine();             // trims end of line character
      if (s == null)
        break;
      bufOut.write(s);
      bufOut.newLine();                 // adds an end of line character
    }

    // Flush anything remaining and release resouurces
    bufIn.close();
    bufOut.close();
    bufIn = null;
    bufOut = null;
  }
}