Two really easy ways spring to mind.  First you can just take a copy of  
your whole source tree and work on that.  Secondly, you could just rename  
the old file out of the way and make, call it something like  
"Point.java_old" so that it doesn't get picked up by the compiler but is  
still there and can be reverted to it's old name if you want to use it  
again.

This is a reasonable approach as you are getting started, but eventually  
you will want to look into something like Subversion or CVS.

Dan.

no. Later in your career you will learn  to use a version control
system so you can maintain several branches.  See
http://mindprod.com/jgloss/cvs.html

the best you can do now is save under a variety of names, and copy one
of the old ones onto Point.java when you want to make it the active
version.

"Ueland" <bobueland@yahoo.com> wrote in news:1131110326.622630.218450
@z14g2000cwz.googlegroups.com:

Good!  That's the best way to learn to write clean code.  Later you may
use an IDE to be able to work faster, but to learn you should work with
a simple editor and compile from the command line.

Sure, you just rename the old version.  You can automate this with the
following Java program:

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.nio.channels.FileChannel;

public class VersionControl
{
  public static void main(String[] args) throws Exception
  {
     File fFile = new File(args[0]);
     int counter = 0;
     File fDest = new File(args[0] + "." + counter);
     while(fDest.exists())
        fDest = new File(args[0] + "." + ++counter);

     FileChannel in = null, out = null;
     try
     {
        in = new FileInputStream(fFile).getChannel();
        out = new FileOutputStream(fDest).getChannel();

        in.transferTo( 0, in.size(), out);
     }
     finally
     {
        if (in != null)
           in.close();
        if (out != null)
           out.close();
     }
  }
}

Just compile this, and run it like this:
java VersionControl Point.java

This will create a copy of Point.java on which you can work, and the old
version will be saved as Point.java.0  On subsequent calls you'll get
Point.java.1, Point.java.2, etc.

As an exercise, try to figure out how VersionControl works.  Add a fail-
safe in case you forget to enter the filename as argument.  Also add
some code to recover from I/O errors while trying to copy the file.

I can think of at least two ways to achieve this result.

Option 1) Use version control

Option 2) Use the file system
 c:\my projects\version1\Point.java
 c:\my projects\version2\Point.java
 ....
 c:\my projects\versionX\Point.java

Jussi Jumppanen
Author: Zeus for Windows Programmer's IDE
http://www.zeusedit.com