Question

我想使用Java将属性附加到XML中的现有元素。例如：

<employee>
<details name="Jai" age="25"/>
<details name="kishore" age="30"/>
</employee>

它希望向其添加weight（假设它已计算，然后在响应中附加）。如何将其附加到所有项目？

<details name="Jai" age="25" weight="55"/>

Answer 1

import org.w3c.dom.*;
import java.io.*;
import javax.xml.parsers.*;
import javax.xml.transform.*;
import javax.xml.transform.dom.*;
import javax.xml.transform.stream.*;

public class AddAndPrint {

  public static void main(String[] args) {    
    DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();
    DocumentBuilder docBuilder = docFactory.newDocumentBuilder();
    Document doc = docBuilder.parse("/path/to/file.xml");
    NodeList employees = document.getElementsByTagName("employee");
    for (Node employee : employees) {
      for (Node child : employee.getChildNodes() {
        if ("details".equals(child.getNodeName()) child.setAttribute("weight", "150");
       }
     }

     try {
       Source source = new DOMSource(doc);
       StringWriter stringWriter = new StringWriter();
       Result result = new StreamResult(stringWriter);
       TransformerFactory factory = TransformerFactory.newInstance();
       Transformer transformer = factory.newTransformer();
       transformer.transform(source, result);
       System.out.println(stringWriter.getBuffer().toString());
     } catch (TransformerConfigurationException e) {
       e.printStackTrace();
     } catch (TransformerException e) {
       e.printStackTrace();
     }
  }
}

Answer 2

以下是基于jdom的快速解决方案：

public static void main(String[] args) throws JDOMException, IOException {
    File xmlFile = new File("employee.xml");
    SAXBuilder builder = new SAXBuilder();
    Document build = builder.build(xmlFile);        
    XPath details = XPath.newInstance("//details");
    List<Element> detailsNodes = details.selectNodes(build);
    for (Element detailsNode:detailsNodes) {
        detailsNode.setAttribute("weight", "70");  // static weight for demonstration
    }
    XMLOutputter outputter = new XMLOutputter(Format.getPrettyFormat());
    outputter.output(build, System.out);
}

首先，我们构建一个文档（SAXBuilder），接下来我们为details节点创建一个XPath表达式，然后我们迭代该表达式的元素并添加权重属性。

最后两行只是验证它是白魔术： - ）

如何将属性附加到Java中的现有XML元素？

2 个答案: