I have a class extending listFragment. I have written code for fetching json response in a method which is called in oncreate of the class. For fetching json in background I have created new inner class which extends asyncTask. I can get the jsonarrays and strings in the json response in the logcat. But when I try to save them in a string array and pass them my custom baseadapter, I get a nullpointer exception.
public class OnlineInfo extends ListFragment {
public static String result;
public String[] Technologies1;
public String[] TechnologyDescription1;
@Override
public void onListItemClick(ListView l, View v, int position, long id) {
// TODO Auto-generated method stub
super.onListItemClick(l, v, position, id);
}
@Override
public void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
downloadjsonresponse();
}
public class Download extends AsyncTask<String, Void, String>
{
@Override
protected String doInBackground(String... params) {
// TODO Auto-generated method stub
StringBuilder stringbuilder = new StringBuilder();
HttpClient client = new DefaultHttpClient();
HttpGet url = new HttpGet(params[0]);
try
{
Log.d("in background", "in background");
HttpResponse response = client.execute(url);
HttpEntity entity = response.getEntity();
InputStream stream = entity.getContent();
BufferedReader reader = new BufferedReader(new InputStreamReader(stream));
String line ;
while((line = reader.readLine()) != null)
{
stringbuilder.append(line);
}
}
catch(ClientProtocolException e)
{
Log.d("error in clientprotocol", "error");
e.printStackTrace();
}
catch(IOException e)
{
Log.d("error in IO", "error");
e.printStackTrace();
}
return stringbuilder.toString();
}
@Override
protected void onPostExecute(String result) {
// TODO Auto-generated method stub
OnlineInfo.result = result;
try {
JSONObject jsonobject = new JSONObject(result);
JSONArray raja = jsonobject.getJSONArray("Technologies");
//String raja = jsonobject.getJSONArray("Technologies").getJSONObject(0).getString("desc");
//Log.d("desc:", raja);
for(int i=0; i<raja.length();i++)
{
Technologies1[i] = raja.getJSONObject(i).getString("name");
TechnologyDescription1[i] = raja.getJSONObject(i).getString("desc");
Log.d("technology :", raja.getJSONObject(i).getString("name"));
Log.d("technologydescription :", raja.getJSONObject(i).getString("desc"));
}
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
Log.d("desc:", "error");
}
getListView().setAdapter(new AdapterForOnlineInfo(getActivity(), OnlineInfo.this.Technologies1, OnlineInfo.this.TechnologyDescription1));
}
}
public void downloadjsonresponse()
{
Download jsonresponse = new Download();
jsonresponse.execute("http://www.avantajsoftwares.com/result.json");
}
}
I could get the results in logcat whenever I comment these two lines in for-loop:
Technologies1[i] = raja.getJSONObject(i).getString("name");
TechnologyDescription1[i] = raja.getJSONObject(i).getString("desc");
Don't know what's going wrong. Please somebody provide me some insight....:-(
