说明：  从数据岛menuXML中读取数据,从树的根节点开始分析树, 利用 hasChildNodes() [方法:是否含有子节点 ] 判断当前 节点是否有子节点,如果有子节点继续向下分析 childNodes [对象:子节点对象集合] ,否则返回当前分析结果(树结点对象)。
(From the data island menuXML read data from the beginning of analysis of tree root tree, use hasChildNodes () [method: whether it contains any child nodes] to determine whether the current node has child nodes, if there is continuing downward analysis of child nodes childNodes [object: child nodes collection object], or else return the current results of the analysis (tree node objects).)