Java:XML dom 解析仅检索数组的 1 个元素

Question

我有以下 XML(由 Web 服务提供)

<?xml version="1.0" encoding="UTF-8"?>
<itam>
   <status>OK</status>
   <data>
      <item0>
         <id>246</id>
         <prefisso_quadrato>1</prefisso_quadrato>
         <id_incontro_corrente />
         <id_giornata>65</id_giornata>
         <round>R1</round>
         <tempo>120</tempo>
         <punti_chong>0</punti_chong>
         <punti_hong>0</punti_hong>
         <amm_chong>0</amm_chong>
         <amm_hong>0</amm_hong>
      </item0>
      <item1>
         <id>247</id>
         <prefisso_quadrato>2</prefisso_quadrato>
         <id_incontro_corrente />
         <id_giornata>65</id_giornata>
         <round>R1</round>
         <tempo>120</tempo>
         <punti_chong>0</punti_chong>
         <punti_hong>0</punti_hong>
         <amm_chong>0</amm_chong>
         <amm_hong>0</amm_hong>
      </item1>
      <item2>
         <id>248</id>
         <prefisso_quadrato>3</prefisso_quadrato>
         <id_incontro_corrente />
         <id_giornata>65</id_giornata>
         <round>R1</round>
         <tempo>120</tempo>
         <punti_chong>0</punti_chong>
         <punti_hong>0</punti_hong>
         <amm_chong>0</amm_chong>
         <amm_hong>0</amm_hong>
      </item2>
   </data>
</itam>

我正在尝试用JAVA解析它。我可以访问<status>以及<data>元素。但是当我尝试迭代<data>时items，我只能读取 1 个元素。这是代码:

DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = factory.newDocumentBuilder();
InputSource is = new InputSource(new StringReader(xml));
Document doc = builder.parse(is);
doc.getDocumentElement().normalize();
System.out.println(doc.getDocumentElement().getElementsByTagName("data").getLength());

OUTPUT: 1

我的想法类似于下面的代码，但它仅在第一个元素上运行(我可以读取其余元素属性，然后结束)。我该如何修复它？非常感谢

DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = factory.newDocumentBuilder();
InputSource is = new InputSource(new StringReader(xml));
Document doc = builder.parse(is);
doc.getDocumentElement().normalize();
NodeList nodelist = doc.getDocumentElement().getElementsByTagName("data");
if(nodelist!=null){
   for(int i=0; i<nodelist.getLength(); i++){
      Element el = (Element) nodelist.item(i);
      //use el to get data from it
   }
}

Answer 1

错误是您正在查找 <data> 的列表元素，而你只有一个。解决方案可以是:

    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    DocumentBuilder builder = factory.newDocumentBuilder();
    InputSource is = new InputSource(new StringReader(xml));
    Document doc = builder.parse(is);
    doc.getDocumentElement().normalize();
    NodeList items = doc.getDocumentElement().getElementsByTagName("data").item(0).getChildNodes();

    for(int i=0; i<items.getLength(); i++){
        System.out.println(items.item(i).getNodeName());
    }

祝你好运!