Null pointer exception during android list update

Question

I want to update the list view after the download is complete, but this gives me a Nullpointer exception to my code according to

 try {URL url = new URL (GlobalVariable.Getstr ());  HttpURLConnection c = (HttpURLConnection) url.openConnection ();  c.setRequestMethod ("GET");  c.setDoOutput (true);  c.connect ();  int lenghtOfFile = c.getContentLength ();  Log.d ("ANDRO_ASYNC", "Lenght of file:" + lenghtOfFile);  String PATH = Environment.getExternalStorageDirectory () + "/ download /";  Log.v (LOG_TAG, "PATH:" + PATH);  File file = new File (PATH);  file.mkdirs ();  // String fileName = "workTest.mp3";  String fileName = GlobalVariable.Getstrpath (). ToString ();  File outputFile = new File (file, fileName);  FileOutputStream fos = new FileOutputStream (outputFile);  InputStream is = c.getInputStream ();  byte [] buffer = new byte [1024];  // int len1 = 0;  long total = 0;  // while ((len1 = is.read (buffer))! = -1) {// total + = len1;  // publishProgress ("" + (int) ((total * 100) / lenghtOfFile));  // fos.write (buffer, 0, len1);  // while ((count = is.read (buffer))! = -1) {total + = count;  publishProgress ("" + (int) ((total * 100) / lenghtOfFile));  fos.write (buffer, 0, len1);  } fos.close ();  is.close ();  // ArrayAdapter aa = new ArrayAdapter (FindFilesByType.this, android.R.layout.test_list_item, Ringtones);  // aa.setNotifyOnChange (true);  // lv1.setAdapter (aa);  try {((ArrayAdapter) lv1.getAdapter ()). notifyDataSetChanged ();  // adapter.notifyDataSetChanged ();  } catch (Exception e) {Log.i (LOG_TAG, "Error:" + e.toString ());  } 

I get

04-28 15:56:17.198: INFO/app(624): Error: java.lang.NullPointerException

what is wrong i doing?

early

Answer 1

Which line throws an exception.

and use notifyDataSetChanged (); method on the adapter , not lvl.getAdapter (). notifyDataSetChanged ();

edited: notifydatasetChange see this

Hope this helps.