Copying files that are updated.

Question

I wanted to make a program that copies files from a directory (and subdirectories) to another location.
So let's say I have a folder in C:\myfolder . In this folder there is another folder (myfolder2) and some type of file(s) (.txt .docx etc.). In myfolder2 there are/is some file(s) also.
I want this program to check each and every FILE if it is older than a FILE in some other location (C:\myotherfolder). If the file does not exist in myotherfolder then it should copy it also.
So the question is: Does someone know a good and effective way of copying ONLY the files that are "new" but leave the others alone AND reach into as many subdirectories as possible.
Here is an effort in doing this but I have stopped since I'm afraid that this would require me to make alot of if statements if there are many subfolders:
import java.io.File;
* @author Simmi
* @version 15.sept.2009
public class CompareFiles
    // instance variables - replace the example below with your own
    private String f1;    // The location to be copied.
    private String f2;      // The location to copy to.
    private String files[];    
    private String files2[];
    private String relation;  // Not used at the moment.
    private long d1;    // Not used at the moment. Going to be used to compare the date of two files.
    private long d2;    // Not used at the moment. Going to be used to compare the date of two files.
     * Constructor for objects of class CompareFiles
    public CompareFiles(String f1,String f2)
        this.f1 = f1;
        this.f2 = f2;
        initialize();
    public void compare()
    public void printDetails()
    private void initialize()
        File src = new File(f1);
        String files[] = src.list();   // Not sure if this is a good way.
        File dst = new File(f2);
        String files2[] = dst.list();    // Not sure if this is a good way.
        if(src.isDirectory())
        if(!dst.exists())
            dst.mkdir();
            for(String string : files)
                File myfile = new File(f1,string);
                if(myfile.isDirectory())        //  Here I halted.
                System.out.println(string.toString());   //  Only to test if all the files are there.
}

Answer 1

This lists the files on your C Drive. You may want to change where it starts or at least run it in your IDE so you can stop it.
import java.io.File;
import java.io.IOException;
public class ForumJunk {
  public ForumJunk(){
    File f = new File("C:/");
    listDirContents(f.listFiles());
  public void listDirContents(File[] s){
    for(int i=0; i<s.length; i++){
      if(s.isDirectory()) listDirContents(s[i].listFiles()); //recurse
try{
System.out.println(s[i].getCanonicalPath());
}catch(IOException e){
System.out.println(e.toString());
public static void main(String[] args) {
new ForumJunk();