java 线程中的run方法中有close: 是什么意思 

 public void run() {
            close:         //就这个
            while (isPlay) {
                for (int i = showIndex; i < maxIndex + 1; i++) {
                              showPointedPhoto(i);
                          try {
                             Thread.sleep((secondComboBox.getSelectedIndex() + 1) * 1000);
                            while (isPause) { Thread.sleep(500);}
                    } catch (InterruptedException e) {e.printStackTrace();}