@SuppressWarnings("unchecked")
	public static void readNode(Element root, String prefix) {
		if (root == null)
			return;
		// ȡ
		List<Attribute> attrs = root.getAttributes();
		if (attrs != null && attrs.size() > 0) {
			System.err.print(prefix);
			for (Attribute attr : attrs) {
				System.err.print(attr.getValue() + " ");
			}
			System.err.println();
		}
		// ȡӽڵ
		List<Element> childNodes = root.getChildren();
		prefix += "\t";
		for (Element e : childNodes) {
			readNode(e, prefix);
		}
	}