Android中XmlSerializer生成xml文件

try {

  File f = new File(getExternalCacheDir().getAbsolutePath()+"my.xml");
OutputStream outPut = new FileOutputStream(f);

   XmlSerializer serializer=Xml.newSerializer(); 

   serializer.setOutput(outPut, "utf-8"); 

   serializer.startDocument("utf-8", true); 

   serializer.startTag(null, "companys"); 

   for(String[] s:taxiCompany) 

   { 

      serializer.startTag(null, DBUtil.TAXI_TABLE); 

      serializer.attribute(null, DBUtil.KEY_PROVINCE, s[0]); 

      serializer.attribute(null, DBUtil.KEY_CITYNAME, s[1]);

      serializer.attribute(null, DBUtil.KEY_NAME, s[2]); 

      serializer.attribute(null, DBUtil.KEY_TELE, s[3]); 

      serializer.endTag(null, DBUtil.TAXI_TABLE); 

   } 

   serializer.endTag(null, "companys"); 

   serializer.endDocument(); 

   outPut.close();

  } catch (IOException e) {

   // TODO Auto-generated catch block

   e.printStackTrace();

  }

private static void XmlFileCreator(List data){
        File newxmlfile = new File(Environment.getExternalStorageDirectory()+"/new.xml");
        try{
            if(!newxmlfile.exists())
                newxmlfile.createNewFile();
        }catch(IOException e){
            Log.e("IOException", "exception in createNewFile() method");
        }
        //we have to bind the new file with a FileOutputStream
        FileOutputStream fileos = null;       
        try{
            fileos = new FileOutputStream(newxmlfile);
        }catch(FileNotFoundException e){
            Log.e("FileNotFoundException", "can't create FileOutputStream");
        }
        //we create a XmlSerializer in order to write xml data
        XmlSerializer serializer = Xml.newSerializer();
        try {
            //we set the FileOutputStream as output for the serializer, using UTF-8 encoding
            serializer.setOutput(fileos, "UTF-8");
            //Write             serializer.startDocument(null, Boolean.valueOf(true));
            //set indentation option
            serializer.setFeature("http://xmlpull.org/v1/doc/features.html#indent-output", true);
          //start a tag called "root"
            serializer.startTag(null, "jokes");
            for(JokeBean joke:data){
                serializer.startTag(null, "joke");
                //i indent code just to have a view similar to xml-tree
                serializer.startTag(null, "id");
                serializer.text(joke.getId());
                serializer.endTag(null, "id");
                                  
                serializer.startTag(null, "title");
                serializer.text(joke.getTitle());
                //set an attribute called "attribute" with a "value" for
                //serializer.attribute(null, "attribute", "value");
                serializer.endTag(null, "title");
                serializer.startTag(null, "text");
                //write some text inside
                serializer.text(joke.getText());
                serializer.endTag(null, "text");
                                  
                serializer.endTag(null, "joke");
            }
            serializer.endTag(null, "jokes");
            serializer.endDocument();
            //write xml data into the FileOutputStream
            serializer.flush();
            //finally we close the file stream
            fileos.close();
        } catch (Exception e) {
            Log.e("Exception","error occurred while creating xml file");
        }
    }