DOM的我知道，SAX呢？怎么做呢？
最好有个例子

SAXParserFactory spf = SAXParserFactory.newInstance();
spf.setValidating(true);

参考一下几个类的用法。
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import org.xml.sax.ErrorHandler;
import org.xml.sax.SAXParseException;

例程：
class MyErrorHandler implements ErrorHandler{//inner class that implements Interface ErrorHandler
        public void warning(SAXParseException exception) throws SAXException{
          System.out.println("**Parsing Warning**n"+
                                      " Line:   "+
                                      exception.getLineNumber()+"n"+
                                      "URI:    "+
                                       exception.getSystemId()+"n"+
                                      "Message:  "+
                                       exception.getMessage());
            throw new SAXException("Warning encountered");

     }
        public void  error(SAXParseException exception)throws SAXException{
             System.out.println("**Parsing Error**n"+
                                      " Line:   "+
                                      exception.getLineNumber()+"n"+
                                      "URI:    "+
                                       exception.getSystemId()+"n"+
                                      "Message:  "+
                                       exception.getMessage());
            throw new SAXException("Error encountered");
        }
   public void fatalError(SAXParseException exception) throws SAXException{
          System.out.println("*****Parsing Error*****n"+
                                      " Line:   "+
                                      exception.getLineNumber()+"n"+
                                      "URI:    "+
                                       exception.getSystemId()+"n"+
                                      "Message:  "+
                                       exception.getMessage());
            throw new SAXException("Fatal Error encountered");
       }
   }