public static void main(String[] args) {

         File f = new File("D://test//fsd");
         listChids(f,0);

     }

     public static void listChids(File f,int level){

         String preSrt = "";
         for(int i=0;i<level;i++){

             preSrt += "----";
         }

         System.out.println(preSrt+f.getName());

         if(!f.isDirectory()){

             return ;
         }else{

             File[] fs = f.listFiles();
             for(int i=0;i<fs.length;i++){

                 listChids(fs[i], level+1);
             }
         }
     }