Question

假设我有一个XML文件：

<catalog>
   <book>
      <isbn>1</isbn>
      <author> A</author>
      <title>Title A</title>
      <description> Desc A</description>
   </book>
   <book>
      <isbn>2</isbn>
      <author>B</author>
      <title>Title B</title>
      <description>Desc B</description>
   </book>
  ...
<catalog>

根据Android documentation，我可以像这样获取我的Activity中的所有数据：

public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        ...
        stringXmlContent = getEventsFromAnXML(this);
        ...

}

private String getEventsFromAnXML(Activity activity)
            throws XmlPullParserException, IOException {
        StringBuffer stringBuffer = new StringBuffer();
        Resources res = activity.getResources();
        XmlResourceParser xpp = res.getXml(R.xml.myxmlfile  );
        xpp.next();
        int eventType = xpp.getEventType();
        while (eventType != XmlPullParser.END_DOCUMENT) {
            if (eventType == XmlPullParser.START_TAG) {
                stringBuffer.append("\nSTART_TAG: " + xpp.getName());
            } else if (eventType == XmlPullParser.END_TAG) {
                stringBuffer.append("\nEND_TAG: " + xpp.getName());
            } else if (eventType == XmlPullParser.TEXT) {
                stringBuffer.append("\nTEXT: " + xpp.getText());
            }
            eventType = xpp.next();
        }

   return stringBuffer.toString();
    }

虽然这会从XML文件中获取所有内容，但我真的很难在特定条件下过滤掉它。

例如，让我们说我想获得isbn为2的书的作者名称。如何使用pullparser过滤掉这些数据？

Answer 1

检查并根据您的需要进行修改

  URL url2 = new URL("http://ws.audioscrobbler.com/2.0/?method=artist.getinfo&artist=" +artist+              "&api_key=1732077d6772048ccc671c754061cb18");
    URLConnection connection = url2.openConnection();
    connection.setConnectTimeout(10000);
    connection.setReadTimeout(30000);

    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
    DocumentBuilder db = dbf.newDocumentBuilder();

    final Document document = db.parse(connection.getInputStream());
    document.getDocumentElement().normalize();
    XPathFactory xPathfactory = XPathFactory.newInstance();
    XPath xPathEvaluator = xPathfactory.newXPath();
    XPathExpression nameExpr = xPathEvaluator.compile("//lfm/artist/image");
    // XPathExpression nameExpr = xPathEvaluator.compile("//lfm/tracks/track/image");
    NodeList nl = (NodeList) nameExpr.evaluate(document, XPathConstants.NODESET);


    for (int zzz = 0; zzz < nl.getLength(); zzz++)
    {
        Node currentItem = nl.item(zzz);
        key = currentItem.getTextContent();


        // key = currentItem.getAttributes().getNamedItem("uri").getNodeValue();
    }

在变量键中，我得到包含图像的节点的值

Answer 2

它需要一些猜测和检查（至少这是我在做的时候所需要的），但你可以轻松测试某个节点的文本，看看ISBN是否为2（如果是，你可以继续解析数据。否则，你可以继续前进，直到你到达下一个ISBN节点。

XML Pullparser：获取特定节点的价值

2 个答案: