public class SAXCounter extends DefaultHandler {
private Hashtable tags; //这个Hashtable用来记录tag出现的次数
// 处理文档前的工作
public void startDocument() throws SAXException {
tags = new Hashtable();//初始化Hashtable
}
//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 = localName;
Object value = tags.get(key);
if (value == null) {
// 如果是新碰到的标签，这在Hastable中添加一条记录
tags.put(key, new Integer(1));
} else {
// 如果以前碰到过，得到其计数值，并加1
int count = ((Integer)value).intValue();
count++;
tags.put(key, new Integer(count));
}
}
//解析完成后的统计工作
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");
}
}
//程序入口，用来完成解析工作
static public void main(String[] args) {
String filename = null;
boolean validation = false;
filename="links.xml";
SAXParserFactory spf = SAXParserFactory.newInstance();
XMLReader xmlReader = null;
SAXParser saxParser=null;
try {
// 创建一个解析器SAXParser对象
saxParser = spf.newSAXParser();
// 得到SAXParser中封装的SAX XMLReader
xmlReader = saxParser.getXMLReader();
} catch (Exception ex) {
System.err.println(ex);
System.exit(1);
}
try {
//使用指定的ContentHandler，解析给XML文件，这儿要注意的是，为了
//程序的简单起见，这儿将主程序和ContentHandler放在了一起。实际上
//main方法中所作的所有事情，都与ContentHandler无关。
xmlReader.parse(new File(filename),new SAXCounter());
} catch (SAXException se) {
System.err.println(se.getMessage());
System.exit(1);
} catch (IOException ioe) {
System.err.println(ioe);
System.exit(1);
}
}
}

public class SAXReader extends DefaultHandler ...{
java.util.Stack tags=new java.util.Stack();
//--------------XML Content-------------
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("------Parse End--------");
}
public void startDocument() throws SAXException ...{
System.out.println("------Parse Begin--------");
}
public void startElement(String p0, String p1, String p2, Attributes p3) throws SAXException ...{
tags.push(p1);
}
public void endElement(String p0, String p1, String p2) throws SAXException ...{
tags.pop();
//一个link节点的信息收集齐了，将其格式化输出
if (p1.equals("link")) printout();
}
public void characters(char[] p0, int p1, int p2) throws SAXException ...{
//从栈中得到当前节点的信息
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")) year=new String(p0,p1,p2);
}
private void printout()...{
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 = null;
boolean validation = false;
filename="links.xml";
SAXParserFactory spf = SAXParserFactory.newInstance();
SAXParser saxParser=null;
try ...{
saxParser = spf.newSAXParser();
} catch (Exception ex) ...{
System.err.println(ex);
System.exit(1);
}
try ...{
saxParser.parse(new File(filename),new SAXReader());
} catch (SAXException se) ...{
System.err.println(se.getMessage());
System.exit(1);
} catch (IOException ioe) ...{
System.err.println(ioe);
System.exit(1);
}
}
}