How to get List of all files/directories from a JTree

I have a JTree which contains file/directory, i want to get a list which contains current list of this JTree.

How can i do it?

menuItemZip.addActionListener(new AbstractAction() {
        public void actionPerformed(ActionEvent e) {
            boolean exist=false;
            File[] files = (File[]) tree.getModel().getRoot();
            for (File file : files) {
                if (file.getName().equals(selectedFile.getName()+".zip"))
                    exist = true;
                break;
            }
            if(exist ==true)
            new ZipWorkers(selectedFile,WORKING,status).execute();
            btnRefresh.doClick();
        }
    });

Edited as new solution: just i don't know if it is a good solution?

menuItemZip.addActionListener(new AbstractAction() {
        public void actionPerformed(ActionEvent e) {     
           Enumeration enumeration =  ((TreeNode) tree.getModel().getRoot()).children();
            String filename = selectedFile.getName()+".zip";
            boolean exist=false;
            while (enumeration.hasMoreElements()){
                String file = ((File) enumeration.nextElement()).getName();
                   if(file.equals(filename)){
                       exist=true;
                       break;
                   }
            }
         if(exist ==true)
            new ZipWorkers(selectedFile,WORKING,status).execute();
            btnRefresh.doClick();
        }
    });

You will need to recursively descend into directories (see File.isDirectory() to determine if it is). The recursiveness can be achieved by writing a function that iterates over an array of files and will call itself with the children of a directory

boolean doesExist(File[] files, String searchFileName) {
  boolean exists = false;
  for (File f : files) {
    if (f.getName().equals(searchFileName)) {
      exist = true;
    } else if (f.isDirectory()) {
      exist = doesExist(f.listFiles(), searchFileName);
    }
    if (exist) {
      break; // no need to proceed further
    }
  }
  return exist;
}

then call it with

doesExist((File[]) tree.getModel().getRoot(), selectedFile.getName()+".zip");