/**

      * XPath获取属性值

      * @param root

      * @param xPath

      * @return

      */

     public static String getXPathAttributeValue(Element root, String xPath){

         XPathExpression<Attribute> pp = XPathFactory.instance().compile(xPath,Filters.attribute());

         return pp.evaluateFirst(root).getValue();

     }

     /**

      * XPath获取节点值

      * @param root 主节点

      * @param xPath XPath字符串

      * @return 没有找到返回null

      */

     public static String getXPathText(Element root, String xPath){

         XPathExpression<Text> pp = XPathFactory.instance().compile(xPath,Filters.text());

         return pp.evaluateFirst(root).getText();

     }

     /**

      * XPath获取节点

      * @param root 主节点

      * @param xPath XPath字符串

      * @return 没有找到返回null

      */

     public static Element getXPathNode(Element root, String xPath){

         XPathExpression<Element> pp = XPathFactory.instance().compile(xPath,Filters.element());

         return pp.evaluateFirst(root);

     }

     /**

      * XPath获取节点集合

      * @param root 主节点

      * @param xPath XPath字符串

      * @return XPath得到的节点集合

      */

     public static List<Element> getXPathNodes(Element root, String xPath){

         XPathExpression<Element> pp = XPathFactory.instance().compile(xPath,Filters.element());

         return pp.evaluate(root);

     }