public class FileChooser extends JFrame{ 
File file = chooser.getSelectedFile();｝

public class AAAAA {
    public static void main(String[] args) throws Exception {
        
        DocumentBuilderFactory domfac = DocumentBuilderFactory.newInstance();
        DocumentBuilder builder = domfac.newDocumentBuilder();
        
        new FileChooser().setVisible(true); 
        
        InputStream is = new FileInputStream();
        Document doc = builder.parse(is);｝