SAX解析实例

//以下代码统计url.xml文件中每个标签出现的次数package com.app;import java.io.File;import java.util.Enumeration;import java.util.Hashtable;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 TagCounter extends DefaultHandler {// Hashtable用来记录tag出现的次数private Hashtable tags;public void startDocument() throws SAXException {tags = new Hashtable();}// 解析完成后的工作public void endDocument() throws SAXException {Enumeration e = tags.keys();while (e.hasMoreElements()) {String tag = (String) e.nextElement();int count = ((Integer) tags.get(tag)).intValue();System.out.println("Tag <" + tag + "> occurs " + count + " times");}}// 对每一个开始元属进行处理public void startElement(String namespaceURI, String localName,String rawName, Attributes atts) throws SAXException {String key = rawName;Object value = tags.get(key);if (value == null) {// 如果是新标签，把它添加在Hastable中tags.put(key, new Integer(1));} else {// 如果以前碰到过，得到其计数值，并加1int count = ((Integer) value).intValue();count++;tags.put(key, new Integer(count));}}static public void main(String[] args) {String filename = null;filename = "url.xml";SAXParserFactory spf = SAXParserFactory.newInstance();SAXParser saxParser = null;try {// 创建解析器SAXParser对象saxParser = spf.newSAXParser();saxParser.parse(new File(filename), new TagCounter());} catch (Exception ex) {ex.printStackTrace();}}}//以下程序解析url.xmlpackage com.app;import java.io.File;import java.io.IOException;import java.util.Stack;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 SAXXMLReader extends DefaultHandler {Stack tags = new Stack();// 用于保存解析出来的信息String text = null;String url = null;String author = null;String description = null;String day = null;String year = null;String month = null;public void endDocument() throws SAXException {System.out.println("------解析结束--------");}public void startDocument() throws SAXException {System.out.println("------解析开始--------");}public void startElement(String p0, String p1, String p2, Attributes p3)throws SAXException {tags.push(p2);}public void endElement(String p0, String p1, String p2) throws SAXException {tags.pop();if (p2.equals("link"))parser();}public void characters(char[] p0, int p1, int p2) throws SAXException {// 察看栈顶元素，根据元素名称给对应的变量赋值String tag = (String) tags.peek();if (tag.equals("text"))text = new String(p0, p1, p2);else if (tag.equals("url"))url = new String(p0, p1, p2);else if (tag.equals("author"))author = new String(p0, p1, p2);else if (tag.equals("day"))day = new String(p0, p1, p2);else if (tag.equals("month"))month = new String(p0, p1, p2);else if (tag.equals("year"))year = new String(p0, p1, p2);else if (tag.equals("description"))description = new String(p0, p1, p2);}private void parser() {System.out.print("Content: ");System.out.println(text);System.out.print("URL: ");System.out.println(url);System.out.print("Author: ");System.out.println(author);System.out.print("Date: ");System.out.println(day + "-" + month + "-" + year);System.out.print("Description: ");System.out.println(description);System.out.println();}static public void main(String[] args) {String filename = "url.xml";SAXParserFactory spf = SAXParserFactory.newInstance();SAXParser saxParser = null;try {saxParser = spf.newSAXParser();saxParser.parse(new File(filename), new SAXXMLReader());} catch (Exception ex) {ex.printStackTrace();}}}