code: public Action getZoomOutAction()
      {
          Action act = new AbstractAction()
          {
              /**
               *
               */
              private static final long serialVersionUID = 5525706163434375107L;
  
              @Override
              public void actionPerformed(ActionEvent e)
              {
                  setZoom(mainMap.getZoom() - 1);
              }
          };
          act.putValue(Action.NAME, "-");
          return act;
      }
docs: Returns an action which can be attached to buttons or menu items to make the map zoom out
  @return a preconfigured Zoom Out action