code: public String[] list()
      {
          String[] list =_file.list();
          if (list==null)
              return null;
          for (int i=list.length;i-->0;)
          {
              if (new File(_file,list[i]).isDirectory() &&
                  !list[i].endsWith("/"))
                  list[i]+="/";
          }
          return list;
      }
docs: Returns a list of resources contained in the given resource