使用DOM解析器读取和写入内部android xml文件

Question

I am new to Android I am trying to read and write some information from and to xml file in Android. I thought it would be possible if I use DOM parser to do such stuff... I am reading file at the beggining of an application to get the data and trying to save before the application terminates to store configuration changes. I figured out how to read file from raw/xml but it seems to be a real pain (or even impossibility) to save modifyied xml back here... Maybe I am taking wrong approach, but I believe it should be possible to somehow modify some internal xml file in Android. How to go about it?

Answer 1

You can not modify or update raw/xml file directory. Android /res directory is Read-Only . So you can only read file from it not write back allowed. ( As Android .apk file has Read-Only permission) .

Answer 2

您cant modify存储在android app的xml folder中的xml folder 。在将设备上安装应用程序到sdcard/internal storage时需要copy该文件，然后进行修改。在这种情况下，您可以使用Dom Parser从sdcard /内部读取和写入xml文件设备的存储。

Answer 3

@user370305 is right!!

simply logic is that you cannot create a file at runtime internally in the storage (raw,asset,layout etc.) So you can create a different file externally by giving the permission "write_external_storage". Then you can read or write.

Here is an example

   public void readXML() throws IOException{ 

         //get the xml file from the raw folder
        InputStream is = getResources().openRawResource(
                    R.raw. config );

        Resources r = getResources();
        AssetManager assetManager = r .getAssets();

         //then write the dummy file
        File f = new File(Environment.getExternalStorageDirectory(), "dummy.xml" );
        OutputStream os = new FileOutputStream(f , true);



         final int buffer_size = 1024 * 1024;
         try
        {
            byte [] bytes = new byte [buffer_size ];
            for (;;)
            {
                int count = is.read( bytes, 0, buffer_size );
                if (count == -1)
                    break ;
                os.write( bytes , 0, count );
            }
            is.close();
            os.close();
        }
         catch (Exception ex )
        {
            ex.printStackTrace();
        }


         //then parse it
                    parseConfigXML( f);

  }

   public String parseConfigXML(File configXML ) {

        XmlPullParser xpp = null ;
         String httpUrl= "";
        FileInputStream fis ;
        XmlPullParserFactory factory = null ;
         try {

               fis = new FileInputStream( configXML);
               factory = XmlPullParserFactory.newInstance();
               factory .setNamespaceAware( true);
               xpp = factory .newPullParser();
               xpp .setInput( new InputStreamReader( fis));

               int eventType = xpp.getEventType();
               while (eventType != XmlPullParser. END_DOCUMENT) {
                     if (eventType == XmlPullParser. START_DOCUMENT) {

                    } else if (eventType == XmlPullParser. START_TAG) {

                    } else if (eventType == XmlPullParser. END_TAG) {

                    } else if (eventType == XmlPullParser. TEXT) {

                           httpUrl += xpp .getText().replace( "\n", "" );

                    }
                     eventType = xpp .next();
              }
        } catch (FileNotFoundException e1 ) {
               // TODO Auto-generated catch block
               e1.printStackTrace();
        } catch (XmlPullParserException e ) {
               // TODO Auto-generated catch block
               e.printStackTrace();
        } catch (IOException e ) {
               // TODO Auto-generated catch block
               e.printStackTrace();
        }

         return httpUrl .trim().replace( "\n", "" );
  }