Java SAX解析器 - 修改XML文檔
演示示例
這是我們需要通過修改XML輸入文件附加 <Result>Pass<Result/>
在</marks>標記結束
<?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>
SAXModifyDemo.java
package com.yiibai.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] += "<?xml version=\"1.0\" encoding=\""+ "UTF-8" + "\"?>"; 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] += '<'; displayText[numberLines] += qualifiedName; if (attributes != null) { int numberAttributes = attributes.getLength(); for (int loopIndex = 0; loopIndex < numberAttributes; loopIndex++){ displayText[numberLines] += ' '; displayText[numberLines] += attributes.getQName(loopIndex); displayText[numberLines] += "=\""; displayText[numberLines] += attributes.getValue(loopIndex); displayText[numberLines] += '"'; } } 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"); } } }
這將產生以下結果:
<?xml version="1.0" encoding="UTF-8"?> <class> <student rollno="393"> <firstname> dinkar </firstname> <lastname> kad </lastname> <nickname> dinkar </nickname> <marks> 85 </marks> <Result> Pass </Result> </student> <student rollno="493"> <firstname> Vaneet </firstname> <lastname> Gupta </lastname> <nickname> vinni </nickname> <marks> 95 </marks> <Result> Pass </Result> </student> <student rollno="593"> <firstname> jasvir </firstname> <lastname> singn </lastname> <nickname> jazz </nickname> <marks> 90 </marks> <Result> Pass </Result> </student> </class>