由XML创建Dom Tree及保存

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import org.apache.batik.dom.svg.SAXSVGDocumentFactory;
import org.apache.batik.util.XMLResourceDescriptor;
import org.w3c.dom.Attr;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
public class DomTree {
public Document doc;
public Element svg;
public DomTree(File file){
String parser=XMLResourceDescriptor.getXMLParserClassName();
SAXSVGDocumentFactory fac=new SAXSVGDocumentFactory(parser);

if(doc == null)
{
//异常点.............
//TMD 这个参数还有格式要求.... NND
//With Batik, you can also create an SVG DOM tree from a URI, an InputStream, or a Reader,
try{
doc=fac.createDocument(file.toURI().toString());
doc.normalize();//去掉XML文档中作为格式化内容的空白而映射在DOM树中的不必要的Text Node对象
svg = doc.getDocumentElement();
}catch(Exception e){
System.out.println("exception");
}
}
}

public Boolean addNode(Element e) throws TransformerException{
svg.appendChild(e);
analyseDoc(doc);
File file=new File("test.xml");
try {
saveDoc(file);

} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
return true;
}

private boolean saveDoc(File file) throws TransformerException, IOException{
TransformerFactory tfactory = Transforme