SAX解析器:如何在不显式给出根名称的情况下获取java中XML的根元素？

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

public class RootElementParser extends DefaultHandler {
    private String rootElement;

    public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
        if (rootElement == null) {
            rootElement = qName;
        }
    }

    public String getRootElement() {
        return rootElement;
    }

    public static void main(String[] args) throws Exception {
        SAXParserFactory factory = SAXParserFactory.newInstance();
        SAXParser parser = factory.newSAXParser();
        RootElementParser handler = new RootElementParser();
        parser.parse("your_xml_file.xml", handler);

        String rootElement = handler.getRootElement();
        System.out.println("根元素名称：" + rootElement);
    }
}