code: public static Object getByXPath(String expression, Object source, QName returnType) {
  		final XPath xPath = createXPath();
  		try {
  			if (source instanceof InputSource) {
  				return xPath.evaluate(expression, (InputSource) source, returnType);
  			} else {
  				return xPath.evaluate(expression, source, returnType);
  			}
  		} catch (XPathExpressionException e) {
  			throw new UtilException(e);
  		}
  	}
docs: 通过XPath方式读取XML节点等信息<br>
  Xpath相关文章：https://www.ibm.com/developerworks/cn/xml/x-javaxpathapi.html
  
  @param expression XPath表达式
  @param source 资源，可以是Docunent、Node节点等
  @param returnType 返回类型，{@link javax.xml.xpath.XPathConstants}
  @return 匹配返回类型的值
  @since 3.2.0