演示示例
这是我们需要修改的XML文档:
<student rollno="393"> <firstname>dinkar</firstname> <lastname>kad</lastname> <nickname>dinkar</nickname> <marks>85</marks> </student> <student rollno="493"> <firstname>Vaneet</firstname> <lastname>Gupta</lastname> <nickname>vinni</nickname> <marks>95</marks> </student> <student rollno="593"> <firstname>jasvir</firstname> <lastname>singh</lastname> <nickname>jazz</nickname> <marks>90</marks> </student>
演示示例:
StAXModifyDemo.java
package com.yiibai.xml; import java.io.File; import java.io.FileNotFoundException; import java.io.FileReader; import java.io.IOException; import java.util.Iterator; import java.util.List; import javax.xml.stream.XMLEventReader; import javax.xml.stream.XMLInputFactory; import javax.xml.stream.XMLStreamConstants; import javax.xml.stream.XMLStreamException; import javax.xml.stream.events.Attribute; import javax.xml.stream.events.StartElement; import javax.xml.stream.events.XMLEvent; import org.jdom2.Document; import org.jdom2.Element; import org.jdom2.JDOMException; import org.jdom2.input.SAXBuilder; import org.jdom2.output.Format; import org.jdom2.output.XMLOutputter; public class StAXModifyDemo { public static void main(String[] args) { try { XMLInputFactory factory = XMLInputFactory.newInstance(); XMLEventReader eventReader = factory.createXMLEventReader( new FileReader("input.txt")); SAXBuilder saxBuilder = new SAXBuilder(); Document document = saxBuilder.build(new File("input.txt")); Element rootElement = document.getRootElement(); List<Element> studentElements = rootElement.getChildren("student"); while(eventReader.hasNext()){ XMLEvent event = eventReader.nextEvent(); switch(event.getEventType()){ case XMLStreamConstants.START_ELEMENT: StartElement startElement = event.asStartElement(); String qName = startElement.getName().getLocalPart(); if (qName.equalsIgnoreCase("student")) { Iterator<Attribute> attributes = startElement.getAttributes(); String rollNo = attributes.next().getValue(); if(rollNo.equalsIgnoreCase("393")){ //get the student with roll no 393 for(int i=0;i < studentElements.size();i++){ Element studentElement = studentElements.get(i); if(studentElement.getAttribute("rollno").getValue().equalsIgnoreCase("393")){ studentElement.removeChild("marks"); studentElement.addContent(new Element("marks").setText("80")); } } } } break; } } XMLOutputter xmlOutput = new XMLOutputter(); // display xml xmlOutput.setFormat(Format.getPrettyFormat()); xmlOutput.output(document, System.out); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (XMLStreamException e) { e.printStackTrace(); } catch (JDOMException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } }
这将产生以下结果:
<student rollno="393"> <firstname>dinkar</firstname> <lastname>kad</lastname> <nickname>dinkar</nickname> <marks>80</marks> </student> <student rollno="493"> <firstname>Vaneet</firstname> <lastname>Gupta</lastname> <nickname>vinni</nickname> <marks>95</marks> </student> <student rollno="593"> <firstname>jasvir</firstname> <lastname>singh</lastname> <nickname>jazz</nickname> <marks>90</marks> </student>