同样用java追加xml问题。急！！！！！！！！！！！！11
public class AddBook {
String id=null;
String title=null;
String author=null;
public AddBook(String id,String title,String author) {
this.id=id;
this.title=title;
this.author=author;
}
public void add(Document doc){//这是追加的方法
Element book=doc.createElement( "book ");
Element eid=doc.createElement( "id ");
Element etitle=doc.createElement( "title ");
Element eauthor=doc.createElement( "author ");
Text tid=doc.createTextNode(id);
Text ttitle=doc.createTextNode(title);
Text tauthor=doc.createTextNode(author);
Node nid=book.appendChild(eid).appendChild(tid);
Node ntitle=book.appendChild(etitle).appendChild(ttitle);
Node nauthro=book.appendChild(eauthor).appendChild(tauthor);
Node nbook=doc.getDocumentElement().appendChild(book);
}
public void ptintdoc(Document doc){
NodeList list=doc.getElementsByTagName( "* ");
Element e=null;
for (int i = 0; i < list.getLength(); i++) {
e=(Element) list.item(i);
System.out.println(e.getNodeName()+ ": "+e.getFirstChild().getNodeValue());
}
}
public static void main(String[] arg){
AddBook addbook=new AddBook(arg[0],arg[1],arg[2]);
DocumentBuilderFactory dbfactory=DocumentBuilderFactory.newInstance();
try {
DocumentBuilder dbbuilder = dbfactory.newDocumentBuilder();
Document doc=dbbuilder.parse(new File( "D:\\untitled1\\book.xml "));
addbook.add(doc);

addbook.ptintdoc(doc);
} catch (Exception ex) {
System.out.println(ex.toString());
}
}

}

为甚么程序运行时显示了追加的元素，而我的book.xml却没有加进去

[解决办法]
//http://topic.csdn.net/t/20030108/09/1337338.html
package javaee;

import org.w3c.dom.*;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.DocumentBuilder;
import java.io.File;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.Transformer;

public class AddBook {
String id = null;
String title = null;
String author = null;
public AddBook(String id, String title, String author) {
this.id = id;
this.title = title;
this.author = author;
}

public void add(Document doc) { //这是追加的方法
Element book = doc.createElement( "book ");
Element eid = doc.createElement( "id ");
Element etitle = doc.createElement( "title ");
Element eauthor = doc.createElement( "author ");
Text tid = doc.createTextNode(id);
Text ttitle = doc.createTextNode(title);
Text tauthor = doc.createTextNode(author);
Node nid = book.appendChild(eid).appendChild(tid);
Node ntitle = book.appendChild(etitle).appendChild(ttitle);
Node nauthro = book.appendChild(eauthor).appendChild(tauthor);
Node nbook = doc.getDocumentElement().appendChild(book);

}

public void ptintdoc(Document doc) {
NodeList list = doc.getElementsByTagName( "* ");
Element e = null;
for (int i = 0; i < list.getLength(); i++) {
e = (Element) list.item(i);
System.out.println(e.getNodeName() + ": " +
e.getFirstChild().getNodeValue());
}
}

public static void main(String[] arg) {
AddBook addbook = new AddBook( "12 ", "think in java ", "tom ");
DocumentBuilderFactory dbfactory = DocumentBuilderFactory.newInstance();
try {
DocumentBuilder dbbuilder = dbfactory.newDocumentBuilder();
Document doc = dbbuilder.parse(new File( "D:\\book.xml "));
addbook.add(doc);

TransformerFactory tff = TransformerFactory.newInstance();
Transformer tf = tff.newTransformer();

DOMSource source = new DOMSource(doc);
StreamResult rs = new StreamResult(new File( "D:\\book2.xml "));
tf.transform(source, rs);


addbook.ptintdoc(doc);
} catch (Exception ex) {
System.out.println(ex.toString());
}
}

}
[解决办法]
因为你没输出到文件啊。