如何在java中解析xml文件

在Java中解析XML文件，可以使用以下几种方法：

1. 使用Java内置的DOM解析器（DocumentBuilderFactory和DocumentBuilder）

import java.io.File; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.Node; import org.w3c.dom.NodeList;  public class Main {     public static void main(String[] args) {         try {             File inputFile = new File("input.xml");             DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();             DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();             Document doc = dBuilder.parse(inputFile);             doc.getDocumentElement().normalize();              System.out.println("Root element: " + doc.getDocumentElement().getNodeName());              NodeList nList = doc.getElementsByTagName("student");             for (int temp = 0; temp < nList.getLength(); temp++) {                 Node nNode = nList.item(temp);                 if (nNode.getNodeType() == Node.ELEMENT_NODE) {                     Element eElement = (Element) nNode;                     System.out.println("Student ID: " + eElement.getElementsByTagName("id").item(0).getTextContent());                     System.out.println("Student Name: " + eElement.getElementsByTagName("name").item(0).getTextContent());                 }             }         } catch (Exception e) {             e.printStackTrace();         }     } } 

2. 使用Java内置的SAX解析器（SAXParserFactory和SAXParser）

import java.io.File; import javax.xml.parsers.SAXParser; import javax.xml.parsers.SAXParserFactory; import org.xml.sax.Attributes; import org.xml.sax.SAXException; import org.xml.sax.helpers.DefaultHandler;  public class Main {     public static void main(String[] args) {         try {             File inputFile = new File("input.xml");             SAXParserFactory saxFactory = SAXParserFactory.newInstance();             SAXParser saxParser = saxFactory.newSAXParser();             MyHandler handler = new MyHandler();             saxParser.parse(inputFile, handler);         } catch (Exception e) {             e.printStackTrace();         }     } }  class MyHandler extends DefaultHandler {     @Override     public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {         System.out.println("Start Element: " + qName);     }      @Override     public void characters(char[] ch, int start, int length) throws SAXException {         String content = new String(ch, start, length).trim();         if (content.length() > 0) {             System.out.println("Content: " + content);         }     }      @Override     public void endElement(String uri, String localName, String qName) throws SAXException {         System.out.println("End Element: " + qName);     } } 

3. 使用第三方库Jackson XML

首先，需要在项目中添加Jackson XML依赖。如果使用Maven，可以在pom.xml文件中添加以下依赖：

<dependency>     <groupId>com.fasterxml.jackson.dataformat</groupId>     <artifactId>jackson-dataformat-xml</artifactId>     <version>2.12.3</version> </dependency> 

然后，可以使用以下代码解析XML文件：

import com.fasterxml.jackson.dataformat.xml.XmlMapper; import java.io.File; import java.io.IOException; import java.util.Map;  public class Main {     public static void main(String[] args) {         try {             File inputFile = new File("input.xml");             XmlMapper xmlMapper = new XmlMapper();             Map<String, Object> resultMap = xmlMapper.readValue(inputFile, Map.class);              System.out.println("Root element: " + resultMap.get("root"));         } catch (IOException e) {             e.printStackTrace();         }     } } 

这些方法都可以用于解析XML文件，具体选择哪种方法取决于项目需求和性能要求。