Question

可能重复：
How do I remove a node element by id in XML?

XML结构

<Servers>
    <server ID="12234">  // <-- I want to find by this id and remove the entire node
        <name>Greg</name>
        <ip>127.0.0.1</ip>
        <port>1897</port>
    </server>
    <server ID="42234">
        <name>Bob</name>
        <ip>127.0.0.1</ip>
        <port>1898</port>
    </server>
    <server ID="5634">
        <name>Tom</name>
        <ip>127.0.0.1</ip>
        <port>1497</port>
    </server>
</Servers>

JAVA CODE：

public void removeNodeFromXML(String name)
      throws ParserConfigurationException, SAXException, IOException,
      TransformerException, XPathExpressionException
  {

    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();

    DocumentBuilder builder = factory.newDocumentBuilder();

    Document doc = builder.parse(file_);

    /**
     * BEG FIX ME
     */


    Element element = (Element) doc.getElementsByTagName(name).item(0);
    // Remove the node

    element.removeChild(element);
    // Normalize the DOM tree to combine all adjacent nodes



    /**
     * END FIX ME
     */

    doc.normalize();

      TransformerFactory transformerFactory = TransformerFactory.newInstance();
    Transformer transformer = transformerFactory.newTransformer();
    DOMSource source = new DOMSource(doc);

    StreamResult result = new StreamResult(file_);
    transformer.transform(source, result);
  }

期望的结果

<Servers>
        <server ID="42234">
            <name>Bob</name>
            <ip>127.0.0.1</ip>
            <port>1898</port>
        </server>
        <server ID="5634">
            <name>Tom</name>
            <ip>127.0.0.1</ip>
            <port>1497</port>
        </server>
    </Servers>

Answer 1

您可以使用Xpath获取Node，然后像在代码中一样删除节点。

示例：

 XPathExpression expr = xpath.compile("Server/server[@id="+idToBeDeleted+"]");
 Object result = expr.evaluate(doc, XPathConstants.NODESET);
 nodes = (NodeList) result;
 //if you have atleast 1
 Node nodeToBeRemoved = nodes.item(0)

Answer 2

答案很广泛： Xpath 。 Xpath是一种非常富有表现力的语言，允许您根据XML文档的结构和内容选择XML结构中的节点。

特别是对于你的问题，一些使用xpath的代码大致会像这样

String xpath = "/Servers/server/*[@id='<your data goes here']";
NodeList nodelist = XPathAPI.selectNodeList(doc, xpath);
if (nodelist.getLength()==1) { // you found the node, and there's only one.
    Element elem = (Element)nodelist.item(0);
    ... // remove the node
}

如何通过属性查找xml元素并在java中将其删除

2 个答案: