code: protected boolean checkConnection()
      {
          try{
              super.checkConnection();
          }
          finally
          {
              if (_jarConnection==null)
              {
                  _entry=null;
                  _file=null;
                  _jarFile=null;
                  _list=null;
              }
          }
          return _jarFile!=null;
      }
docs: /* ------------------------------------------------------------