public void dir(){
        if( file.isDirectory() ){
            File childs[] = file.listFiles();
            
            for(File child : childs){
                if( !child.isHidden() ){
                    Date ultima = new Date(child.lastModified());
                    System.out.print(ultima + "\t");

                    if(child.isDirectory())
                        System.out.print("<DIR>\t");
                    if(child.isFile()){
                        System.out.print("     \t");
                        System.out.print(child.length() + " ");
                    }
                    System.out.println(child.getName());
                }
            }
        }
    }