Question

我有一个看起来像这样的xml：

{ <xml><ep><source type="xml">...</source><source type="text">..</source></ep></xml>}

这里我想检索“源类型”的值，其中类型为s属性。

我试过这样，但它不起作用：

 DocumentBuilderFactory domFactory = DocumentBuilderFactory.newInstance();
                try {
                    DocumentBuilder builder = domFactory.newDocumentBuilder();
                    Document dDoc = builder.parse("D:/workspace1/ereader/src/main/webapp/configurations/config.xml");
                    System.out.println(dDoc);
                    XPath xPath = XPathFactory.newInstance().newXPath();
                    Node node = (Node) xPath.evaluate("//xml/source/@type/text()", dDoc, XPathConstants.NODE);
                    System.out.println(node);
                } catch (Exception e) {
                    e.printStackTrace();

我也试过这个：

DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
            DocumentBuilder builder = factory.newDocumentBuilder();
            InputSource is = new InputSource(new StringReader("config.xml"));
            Document doc = builder.parse(is);

            NodeList nodeList = doc.getElementsByTagName("source");

            for (int i = 0; i < nodeList.getLength(); i++) {                
                Node node = nodeList.item(i);

                if (node.hasAttributes()) {
                    Attr attr = (Attr) node.getAttributes().getNamedItem("type");
                    if (attr != null) {
                        String attribute= attr.getValue();                      
                        System.out.println("attribute: " + attribute);                      
                    }
                }
            }

请帮助我!!

提前致谢， Varsha。

Answer 1

由于您的问题更通用，因此请尝试使用Java中提供的XML解析器来实现它。如果您需要特定于解析器，请在此处更新您已尝试过的代码

<?xml version="1.0" encoding="UTF-8"?>
<ep>
    <source type="xml">TEST</source>
    <source type="text"></source>
</ep>

DocumentBuilderFactory domFactory = DocumentBuilderFactory.newInstance();
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = factory.newDocumentBuilder();
Document doc = builder.parse("uri to xmlfile");
XPathFactory xPathfactory = XPathFactory.newInstance();
XPath xpath = xPathfactory.newXPath();
XPathExpression expr = xpath.compile("//ep/source[@type]");
NodeList nl = (NodeList) expr.evaluate(doc, XPathConstants.NODESET);

for (int i = 0; i < nl.getLength(); i++)
{
    Node currentItem = nl.item(i);
    String key = currentItem.getAttributes().getNamedItem("type").getNodeValue();
    System.out.println(key);
}

Answer 2

尝试这样的事情：

    DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
    Document dDoc = builder.parse("d://utf8test.xml");

    XPath xPath = XPathFactory.newInstance().newXPath();
    NodeList nodes = (NodeList) xPath.evaluate("//xml/ep/source/@type", dDoc, XPathConstants.NODESET);
    for (int i = 0; i < nodes.getLength(); i++) {
        Node node = nodes.item(i);
        System.out.println(node.getTextContent());
    }

请注意更改：

我们要求一个节点集（XPathConstants.NODESET），而不仅仅是单个节点。
xpath现在是// xml / ep / source / @ type而不是// xml / source / @type / text（）

PS：你可以在你的问题中添加标签java吗？感谢。

Answer 3

使用

document.getElementsByTagName（＆＃34; *＆＃34;）;

要从XML文件中获取所有XML元素，但这会返回重复属性

示例：

NodeList list = doc.getElementsByTagName（＆＃34; *＆＃34;）;

System.out.println（＆＃34; XML Elements：＆＃34;）;

        for (int i=0; i<list.getLength(); i++) {

            Element element = (Element)list.item(i);
            System.out.println(element.getNodeName());
        }

Answer 4

以下是在VTD-XML

中执行此操作的代码

ave()

Answer 5

我很高兴这个片段工作正常：

DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
Document document = db.parse(new File("config.xml"));
NodeList nodeList = document.getElementsByTagName("source");
for(int x=0,size= nodeList.getLength(); x<size; x++) {
    System.out.println(nodeList.item(x).getAttributes().getNamedItem("type").getNodeValue());
}

Answer 6

public static void main(String[] args) throws IOException {
    String filePath = "/Users/myXml/VH181.xml";
    File xmlFile = new File(filePath);
    DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
    DocumentBuilder dBuilder;
    try {
        dBuilder = dbFactory.newDocumentBuilder();
        Document doc = dBuilder.parse(xmlFile);
        doc.getDocumentElement().normalize();
        printElement(doc);
        System.out.println("XML file updated successfully");
    } catch (SAXException | ParserConfigurationException e1) {
        e1.printStackTrace();
    }
}
private static void printElement(Document someNode) {
    NodeList nodeList = someNode.getElementsByTagName("choiceInteraction");
    for(int z=0,size= nodeList.getLength();z<size; z++) {
            String Value = nodeList.item(z).getAttributes().getNamedItem("id").getNodeValue();
            System.out.println("Choice Interaction Id:"+Value);
        }
    }

我们可以使用方法

来尝试这个代码

如何使用java获取xml节点的属性值

6 个答案: