什么xml错：java.lang.ClassCastException: org.apache.xerces.dom.DeferredDocumentImpl

Question

you are trying to cast some variable to a non-compatible type

Answer 1

你把一个不是org.apache.xerces.dom.DeferredDocumentImpl的造型为一个DeferredDocumentImpl了，仔细看看出错那行有没有造型操作。

Answer 2

程序如下：
import java.io.*;
import javax.xml.parsers.*;
import org.xml.sax.*;
import org.w3c.dom.*;
import com.sun.xml.tree.*;/**
 * <p>Title: </p>
 * <p>Description: </p>
 * <p>Copyright: Copyright (c) 1998</p>
 * <p>Company: </p>
 * @author mzer
 * @version 1.0
 */public class xmldo {        public xmldo() {
        }
        public static void main(String[] args) {
                try
                {
                        //turn xmlfile to byte[]
                        File f = new File("E:\\work\\tool\\src\\tool\\postoffice.xml");
                        FileInputStream fin = new FileInputStream(f);
                        byte[] byteIN = new byte[(int)f.length()];
                        fin.read(byteIN);
                        fin.close();
                        System.out.println("xmlFile open...");                        //append node                        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
                        DocumentBuilder db = dbf.newDocumentBuilder();
                        ByteArrayInputStream bf=new ByteArrayInputStream(byteIN);
                        Document m_dDoc=db.parse(bf);
                        //Document m_dDoc=db.getDOMImplementation();
                        Element eRoot=m_dDoc.getDocumentElement();
                        Element e1,e2;
                        e1=m_dDoc.createElement("id");
                        e2=m_dDoc.createElement("sql");
                        e1.appendChild(m_dDoc.createTextNode("111"));
                        eRoot.appendChild(e1);
                        ByteArrayOutputStream buf=new ByteArrayOutputStream();
                        //FileOutputStream fo=new FileOutputStream("E:\\work\\tool\\src\\tool\\postoffice.xml");
                        //System.out.println("xmlFile open...4");
                        ((XmlDocument)m_dDoc).write(buf);
                        byte[] bArray=buf.toByteArray();
                        FileOutputStream fo=new FileOutputStream("E:\\work\\tool\\src\\tool\\postoffice.xml");
                        fo.write(bArray);
                        fo.close();
                }
                catch(Exception e)
                {
                        e.printStackTrace();
                }        }
}