零教程

演示示例

这是输入需要解析xml文件：

<?xml version="1.0"?>
<class>
   <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>singn</lastname>
      <nickname>jazz</nickname>
      <marks>90</marks>
   </student>
</class>

%uA0

UserHandler.java

package com.yiibai.xml

import org.xml.sax.Attributes
import org.xml.sax.SAXException
import org.xml.sax.helpers.DefaultHandler

public class UserHandler extends DefaultHandler {

   boolean bFirstName = false
   boolean bLastName = false
   boolean bNickName = false
   boolean bMarks = false

   @Override
   public void startElement(String uri, 
   String localName, String qName, Attributes attributes)
      throws SAXException {
      if (qName.equalsIgnoreCase("student")) {
         String rollNo = attributes.getValue("rollno")
         System.out.println("Roll No : " + rollNo)
      } else if (qName.equalsIgnoreCase("firstname")) {
         bFirstName = true
      } else if (qName.equalsIgnoreCase("lastname")) {
         bLastName = true
      } else if (qName.equalsIgnoreCase("nickname")) {
         bNickName = true
      }
      else if (qName.equalsIgnoreCase("marks")) {
         bMarks = true
      }
   }

   @Override
   public void endElement(String uri, 
   String localName, String qName) throws SAXException {
      if (qName.equalsIgnoreCase("student")) {
         System.out.println("End Element :" + qName)
      }
   }

   @Override
   public void characters(char ch[], 
      int start, int length) throws SAXException {
      if (bFirstName) {
         System.out.println("First Name: " 
            + new String(ch, start, length))
         bFirstName = false
      } else if (bLastName) {
         System.out.println("Last Name: " 
            + new String(ch, start, length))
         bLastName = false
      } else if (bNickName) {
         System.out.println("Nick Name: " 
            + new String(ch, start, length))
         bNickName = false
      } else if (bMarks) {
         System.out.println("Marks: " 
            + new String(ch, start, length))
         bMarks = false
      }
   }
}

SAXParserDemo.java

package com.yiibai.xml

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 SAXParserDemo {
   public static void main(String[] args){

      try {	
         File inputFile = new File("input.txt")
         SAXParserFactory factory = SAXParserFactory.newInstance()
         SAXParser saxParser = factory.newSAXParser()
         UserHandler userhandler = new UserHandler()
         saxParser.parse(inputFile, userhandler)     
      } catch (Exception e) {
         e.printStackTrace()
      }
   }   
}

class UserHandler extends DefaultHandler {

   boolean bFirstName = false
   boolean bLastName = false
   boolean bNickName = false
   boolean bMarks = false

   @Override
   public void startElement(String uri, 
      String localName, String qName, Attributes attributes)
         throws SAXException {
      if (qName.equalsIgnoreCase("student")) {
         String rollNo = attributes.getValue("rollno")
         System.out.println("Roll No : " + rollNo)
      } else if (qName.equalsIgnoreCase("firstname")) {
         bFirstName = true
      } else if (qName.equalsIgnoreCase("lastname")) {
         bLastName = true
      } else if (qName.equalsIgnoreCase("nickname")) {
         bNickName = true
      }
      else if (qName.equalsIgnoreCase("marks")) {
         bMarks = true
      }
   }

   @Override
   public void endElement(String uri, 
      String localName, String qName) throws SAXException {
      if (qName.equalsIgnoreCase("student")) {
         System.out.println("End Element :" + qName)
      }
   }

   @Override
   public void characters(char ch[], 
      int start, int length) throws SAXException {
      if (bFirstName) {
         System.out.println("First Name: " 
         + new String(ch, start, length))
         bFirstName = false
      } else if (bLastName) {
         System.out.println("Last Name: " 
         + new String(ch, start, length))
         bLastName = false
      } else if (bNickName) {
         System.out.println("Nick Name: " 
         + new String(ch, start, length))
         bNickName = false
      } else if (bMarks) {
         System.out.println("Marks: " 
         + new String(ch, start, length))
         bMarks = false
      }
   }
}

这将产生以下结果：

Roll No : 393
First Name: dinkar
Last Name: kad
Nick Name: dinkar
Marks: 85
End Element :student
Roll No : 493
First Name: Vaneet
Last Name: Gupta
Nick Name: vinni
Marks: 95
End Element :student
Roll No : 593
First Name: jasvir
Last Name: singn
Nick Name: jazz
Marks: 90
End Element :student