code: public static List<Element> transElements(Element parentEle, NodeList nodeList) {
  		int length = nodeList.getLength();
  		final ArrayList<Element> elements = new ArrayList<Element>(length);
  		Node node;
  		Element element;
  		for (int i = 0; i < length; i++) {
  			node = nodeList.item(i);
  			if (Node.ELEMENT_NODE == node.getNodeType()) {
  				element = (Element) nodeList.item(i);
  				if (parentEle == null || element.getParentNode() == parentEle) {
  					elements.add(element);
  				}
  			}
  		}
  
  		return elements;
  	}
docs: 将NodeList转换为Element列表<br>
  非Element节点将被忽略
  
  @param parentEle 父节点，如果指定将返回此节点的所有直接子节点，nul返回所有就节点
  @param nodeList NodeList
  @return Element列表