Asynctask runining error

Question

I tried to load listview data by using asynctask. when the first activity call to start new activity, it should load new activity and display the data. but my second activity not started.

My second class is

@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.search_data);
    search_data=getIntent().getExtras().getString("Search_Value");

    list = (ListView) findViewById(R.id.listView1);

    accessWebService();

}

class SearchData extends AsyncTask<String, String, String>{


    @Override
    protected void onPreExecute() {
        // TODO Auto-generated method stub
        super.onPreExecute();
    }

    @Override
    protected String doInBackground(String... arg0) {
        // TODO Auto-generated method stub

        List<NameValuePair> params = new ArrayList<NameValuePair>();

        params.add(new BasicNameValuePair("rest_name", search_data));

        Log.d("request!", "starting");

        JSONObject json = jsonParser.makeHttpRequest(Search, "POST", params);

        Log.d("Search", json.toString());

        JSONArray jsonMainNode = json.optJSONArray("Search");

        for (int i = 0; i < jsonMainNode.length(); i++) {
        JSONObject jsonChildNode;
        try {

            jsonChildNode = jsonMainNode.getJSONObject(i);
            String restName = jsonChildNode.optString("name");
            //Toast.makeText(getApplicationContext(), name, Toast.LENGTH_LONG).show();
            String address = jsonChildNode.optString("address");
            String mobile = jsonChildNode.optString("mobile");
            String direction = "Direction: "+jsonChildNode.optString("direction");
            String bestTime = "Best time to visite: "+jsonChildNode.optString("bestTime");
            String food = jsonChildNode.optString("food");
            String dress = jsonChildNode.optString("dress");
            String priceRange = "Price Range: "+jsonChildNode.optString("priceRange");

            Log.d("Dress", dress);

            listData = new ArrayList<String>();
            listData.add(restName);
            listData.add(address);
            listData.add(mobile);
            listData.add(direction);
            listData.add(bestTime);
            listData.add(food);
            listData.add(dress);
            listData.add(priceRange);

        } catch (JSONException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }


        MyListAdapter adapter = new MyListAdapter(Search.this,listData);
        list.setAdapter(adapter);



        }
        return null;
    }

    @Override
    protected void onPostExecute(String result) {
        // TODO Auto-generated method stub
        super.onPostExecute(result);
    }



}

public void accessWebService() {
    SearchData data = new SearchData();
    // passes values for the urls string array
    data.execute();
}

when i run it, following errors were occurred.

01-16 15:19:48.092: E/AndroidRuntime(10724): FATAL EXCEPTION: AsyncTask #1
01-16 15:19:48.092: E/AndroidRuntime(10724): java.lang.RuntimeException: An error occured while executing doInBackground()
01-16 15:19:48.092: E/AndroidRuntime(10724):    at android.os.AsyncTask$3.done(AsyncTask.java:299)
01-16 15:19:48.092: E/AndroidRuntime(10724):    at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
01-16 15:19:48.092: E/AndroidRuntime(10724):    at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
01-16 15:19:48.092: E/AndroidRuntime(10724):    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
01-16 15:19:48.092: E/AndroidRuntime(10724):    at java.util.concurrent.FutureTask.run(FutureTask.java:137)
01-16 15:19:48.092: E/AndroidRuntime(10724):    at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
01-16 15:19:48.092: E/AndroidRuntime(10724):    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
01-16 15:19:48.092: E/AndroidRuntime(10724):    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
01-16 15:19:48.092: E/AndroidRuntime(10724):    at java.lang.Thread.run(Thread.java:856)
01-16 15:19:48.092: E/AndroidRuntime(10724): Caused by: android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.
01-16 15:19:48.092: E/AndroidRuntime(10724):    at android.view.ViewRootImpl.checkThread(ViewRootImpl.java:5073)
01-16 15:19:48.092: E/AndroidRuntime(10724):    at android.view.ViewRootImpl.focusableViewAvailable(ViewRootImpl.java:2809)
01-16 15:19:48.092: E/AndroidRuntime(10724):    at android.view.ViewGroup.focusableViewAvailable(ViewGroup.java:609)
01-16 15:19:48.092: E/AndroidRuntime(10724):    at android.view.ViewGroup.focusableViewAvailable(ViewGroup.java:609)
01-16 15:19:48.092: E/AndroidRuntime(10724):    at android.view.ViewGroup.focusableViewAvailable(ViewGroup.java:609)
01-16 15:19:48.092: E/AndroidRuntime(10724):    at android.view.ViewGroup.focusableViewAvailable(ViewGroup.java:609)
01-16 15:19:48.092: E/AndroidRuntime(10724):    at android.view.View.setFlags(View.java:8414)
01-16 15:19:48.092: E/AndroidRuntime(10724):    at android.view.View.setFocusableInTouchMode(View.java:5693)
01-16 15:19:48.092: E/AndroidRuntime(10724):    at android.widget.AdapterView.checkFocus(AdapterView.java:720)
01-16 15:19:48.092: E/AndroidRuntime(10724):    at android.widget.ListView.setAdapter(ListView.java:467)
01-16 15:19:48.092: E/AndroidRuntime(10724):    at com.example.rp.Search$SearchData.doInBackground(Search.java:102)
01-16 15:19:48.092: E/AndroidRuntime(10724):    at com.example.rp.Search$SearchData.doInBackground(Search.java:1)
01-16 15:19:48.092: E/AndroidRuntime(10724):    at android.os.AsyncTask$2.call(AsyncTask.java:287)
01-16 15:19:48.092: E/AndroidRuntime(10724):    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
01-16 15:19:48.092: E/AndroidRuntime(10724):    ... 5 more

Can anyone help me to solve this problem?

Answer 1

it seems there is a problem with MyListAdapter

MyListAdapter adapter = new MyListAdapter(Search.this,listData);
list.setAdapter(adapter);

You need to call runOnUiThread() from onPostExecute.

      runOnUiThread(new Runnable() {

          @Override
                public void run() {
                   MyListAdapter adapter = new MyListAdapter(Search.this,listData);
                   list.setAdapter(adapter);
                }
          });

Answer 2

Move this to onPostExecute()

    MyListAdapter adapter = new MyListAdapter(Search.this,listData);
    list.setAdapter(adapter);

This is because you can't update your UI in doInbackGround method.

For update your UI you have to update it in onPostExecute method.

In doInbackGround you can perform your Network UI work.

Answer 3

Move these lines to onPostExecute because, doInBackGround will run in Non-UI Thread

MyListAdapter adapter = new MyListAdapter(Search.this,listData);
list.setAdapter(adapter);