思路：SAX工厂-->SAX解析器-->SAX阅读器-->注册事件处理-->解析开始。

对应代码：

public class TestSAX {

public static void main(String[] args) throws Exception{

SAXParserFactory factory = SAXParserFactory.newInstance();

SAXParser parser = factory.newSAXParser();

XMLReader reader = parser.getXMLReader();

reader.setContentHandler(new MyContentHandler());

reader.parse("book.xml");

}

}

class MyContentHandler extends DefaultHandler {

private String elementName = null;

@Override

public void startDocument() throws SAXException {

System.out.println("文档解析开始>>>>>>>>>>>>>>>>>>>>>>>>");

}

@Override

public void startElement(String arg0, String arg1, String arg2,

Attributes arg3) throws SAXException {

elementName = arg2;

}

@Override

public void characters(char[] arg0, int arg1, int arg2) throws SAXException {

if ("书名".equals(elementName)) {

System.out.println(new String(arg0, arg1, arg2));

}

}

@Override

public void endElement(String arg0, String arg1, String arg2)

throws SAXException {

elementName = null;

}

@Override

public void endDocument() throws SAXException {

System.out.println("文档解析结束>>>>>>>>>>>>>>>>>>>>>>>>");

}

}