一个计算tree层次的方法，请大家多提意见

private int getTreeLevel(TreeNode tree) {
		List children = tree.getChildren();
        //当tree 没有层次时
		int level = 0;
		int childLevel = 0;
		for (int i = 0; i < children.size(); i++) {
            //有层次计level=1，level值：1：0
            //level的值为规头值不可省略。
			level= 1;
			TreeNode child = (TreeNode) children.get(i);
            //得到child tree的层次
			int treeLevel = getTreeLevel(child);
            //取所有子tree中最大值，计为子层次值
			childLevel = childLevel >= treeLevel ? childLevel : treeLevel;
		}
       //当前tree的层次为level值+子level值                         
		return level+childLevel;
	}