Java SAX解析器-修改XML文档

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📜 Java SAX解析器-修改XML文档

📅 最后修改于: 2020-11-14 10:26:41 🧑 作者: Mango

示范范例

这是我们需要通过在标记末尾附加 Pass 来修改的输入XML文件。



   
      dinkar
      kad
      dinkar
      85
   
   
   
      Vaneet
      Gupta
      vinni
      95
   
   
   
      jasvir
      singn
      jazz
      90

SAXModifyDemo.java

package com.tutorialspoint.xml;

import java.io.*;
import org.xml.sax.*;
import javax.xml.parsers.*;
import org.xml.sax.helpers.DefaultHandler;

public class SAXModifyDemo extends DefaultHandler {
   static String displayText[] = new String[1000];
   static int numberLines = 0;
   static String indentation = "";

   public static void main(String args[]) {

      try {
         File inputFile = new File("input.txt");
         SAXParserFactory factory = 
         SAXParserFactory.newInstance();
         SAXModifyDemo obj = new SAXModifyDemo();
         obj.childLoop(inputFile);
         FileWriter filewriter = new FileWriter("newfile.xml");
         
         for(int loopIndex = 0; loopIndex < numberLines; loopIndex++) {
            filewriter.write(displayText[loopIndex].toCharArray());
            filewriter.write('\n');
            System.out.println(displayText[loopIndex].toString());
         }
         filewriter.close();
      }
      catch (Exception e) {
         e.printStackTrace(System.err);
      }
   }

   public void childLoop(File input) {
      DefaultHandler handler = this;
      SAXParserFactory factory = SAXParserFactory.newInstance();
      
      try {
         SAXParser saxParser = factory.newSAXParser();
         saxParser.parse(input, handler);
      } catch (Throwable t) {}
   }

   public void startDocument() {
      displayText[numberLines] = indentation;
      displayText[numberLines] += "";
      numberLines++;
   }

   public void processingInstruction(String target, String data) {
      displayText[numberLines] = indentation;
      displayText[numberLines] += "";
      displayText[numberLines] += target;
      
      if (data != null && data.length() > 0) {
         displayText[numberLines] += ' ';
         displayText[numberLines] += data;
      }
      displayText[numberLines] += "?>";
      numberLines++;
   }

   public void startElement(String uri, String localName, String qualifiedName,
      Attributes attributes) {

      displayText[numberLines] = indentation;

      indentation += "    ";

      displayText[numberLines] += '';
      numberLines++;
   }

   public void characters(char characters[], int start, int length) {
      String characterData = (new String(characters, start, length)).trim();
      
      if(characterData.indexOf("\n") < 0 && characterData.length() > 0) {
         displayText[numberLines] = indentation;
         displayText[numberLines] += characterData;
         numberLines++;
      }
   }

   public void endElement(String uri, String localName, String qualifiedName) {
      indentation = indentation.substring(0, indentation.length() - 4) ;
      displayText[numberLines] = indentation;
      displayText[numberLines] += "";
      displayText[numberLines] += qualifiedName;
      displayText[numberLines] += '>';
      numberLines++;

      if (qualifiedName.equals("marks")) {
         startElement("", "Result", "Result", null);
         characters("Pass".toCharArray(), 0, "Pass".length());
         endElement("", "Result", "Result");
      }
   }
}

这将产生以下结果-