用w3c读取xml 文件 使用的jar包：xml-apis-1.0.b2.jar

public static void main(String[] args) throws ParserConfigurationException, SAXException, IOException  {
        //得到DOM解析器的工厂实例
        DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
        //从DOM工厂中获得DOM解析器
        DocumentBuilder dbBuilder = dbFactory.newDocumentBuilder();
        //把要解析的xml文档读入DOM解析器
        Document doc = dbBuilder.parse("C:/Users/Hoperun/workspace1/testAjax1/WebContent/WEB-INF/NewFile.xml");
    //    System.out.println("处理该文档的DomImplementation对象  = "+ doc.getImplementation());
        //得到文档名称为Student的元素的节点列表
        NodeList nList = doc.getElementsByTagName("city");
        for (int i=0;i<nList.getLength();i++){
            System.out.println(nList.item(i).getChildNodes().item(1).getTextContent());
            System.out.println(nList.item(i).getChildNodes().item(3).getTextContent());
            
        }      

    }

NewFile.xml 文件内容：

<response><city><cityname>weqw</cityname><cityvalue>1</cityvalue></city><city><cityname>adf</cityname><cityvalue>2</cityvalue></city><city><cityname>adsf</cityname><cityvalue>3</cityvalue></city></response>

程序运行结果：

weqw1adf2adsf3