零教程

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=0i < 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>