Iterator i = points.iterator();
    while(i.hasNext()){
      Point p = (Point)i.next();
什么意思，码放讲解下

Iterator i = points.iterator(); //迭代器
    while(i.hasNext()){ //如果i下一个有值就返回true
      Point p = (Point)i.next() //将当前的object对象 转换为实体对象