Android setadapter Null pointer

Question

I have following fragment

public class Tab2 extends Fragment {

// Progress Dialog
private ProgressDialog pDialog;

// Creating JSON Parser object
JSONParser jParser = new JSONParser();

ArrayList<HashMap<String, String>> contactsList;

// url to get all contacts list
//private static String url_all_contacts = "http://192.168.100.28/andriod_product_demo/get_all_contacts.php";

// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_CONTACTS = "contacts";
private static final String TAG_PID = "pid";
private static final String TAG_NAME = "name";
private static final String TAG_TYPE = "type";

ListView lv;
//..get the user id from the tinydb
TinyDB objTDB;

// contacts JSONArray
JSONArray contacts = null;

@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    View v = inflater.inflate(R.layout.tab2,container,false);

    objTDB=new TinyDB(getActivity());

    // Hashmap for ListView
    contactsList = new ArrayList<HashMap<String, String>>();

    // Get listview
    //lv = getListView();
    lv = (ListView) v.findViewById(R.id.list);

    // Loading contacts in Background Thread
    new LoadAllContacts().execute();



    /*// on selecting single product
    // launching Edit contact Screen
    lv.setOnItemClickListener(new OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> parent, View view,
                int position, long id) {

            // getting values from selected ListItem
            String pid = ((TextView) view.findViewById(R.id.pid)).getText()
                    .toString();

            // Starting new intent
            Intent in = new Intent(getActivity().getApplicationContext(),
                    EditProductActivity.class);
            // sending pid to next activity
            in.putExtra(TAG_PID, pid);

            // starting new activity and expecting some response back
            startActivityForResult(in, 100);

        }
    });*/

    return v;
}


/**
 * Background Async Task to Load all contact by making HTTP Request
 * */
class LoadAllContacts extends AsyncTask<String, String, String> {

    /**
     * Before starting background thread Show Progress Dialog
     * */
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pDialog = new ProgressDialog(getActivity());
        pDialog.setMessage("Loading contacts. Please wait...");
        pDialog.setIndeterminate(false);
        pDialog.setCancelable(false);
        pDialog.show();
    }

    /**
     * getting All contacts from url
     * */
    protected String doInBackground(String... args) {
        // Building Parameters
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        params.add(new BasicNameValuePair("tag", "get_contact_list")); 
        params.add(new BasicNameValuePair("user_id", String.valueOf(objTDB.getLong(AppConfig.USR_LOG_IN_ID))));
        // getting JSON string from URL
        JSONObject json = jParser.getJSONFromUrl(AppConfig.URL_CONTACTS, params);

        // Check your log cat for JSON reponse
        Log.d("All contacts: ", json.toString());

        try {
            // Checking for SUCCESS TAG
            int success = json.getInt(TAG_SUCCESS);

            if (success == 1) {
                // contacts found
                // Getting Array of contacts
                contacts = json.getJSONArray(TAG_CONTACTS);

                // looping through All contacts
                for (int i = 0; i < contacts.length(); i++) {
                    JSONObject c = contacts.getJSONObject(i);

                    // Storing each json item in variable
                    String id = c.getString(TAG_PID);
                    String name = c.getString(TAG_NAME);
                    String type = c.getString(TAG_TYPE);

                    // creating new HashMap
                    HashMap<String, String> map = new HashMap<String, String>();

                    // adding each child node to HashMap key => value
                    map.put(TAG_PID, id);
                    map.put(TAG_NAME, name);
                    map.put(TAG_TYPE, type);

                    // adding HashList to ArrayList
                    contactsList.add(map);
                }
            } /*else {
                // no contacts found
                // Launch Add New product Activity
                Intent i = new Intent(getApplicationContext(),
                        NewProductActivity.class);
                // Closing all previous activities
                i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                startActivity(i);
            }*/
        } catch (JSONException e) {
            e.printStackTrace();
        }

        return null;
    }

    /**
     * After completing background task Dismiss the progress dialog
     * **/
    protected void onPostExecute(String file_url) {
        // dismiss the dialog after getting all contacts
        pDialog.dismiss();
        // updating UI from Background Thread
        getActivity().runOnUiThread(new Runnable() {
            public void run() {
                /**
                 * Updating parsed JSON data into ListView
                 * */
                ListAdapter adapter = new SimpleAdapter(
                        getActivity(), contactsList,
                        R.layout.list_item, new String[] { TAG_PID,
                                TAG_NAME,TAG_TYPE},
                        new int[] { R.id.pid, R.id.name ,R.id.type});
                // updating listview
                lv.setAdapter(adapter); 
                //setListAdapter(adapter);
            }
        });

    }

}

}

And i am getting following error (from logcat) on line lv.setAdapter(adapter); ,

06-20 09:23:26.996: E/AndroidRuntime(1550): FATAL EXCEPTION: main 06-20 09:23:26.996: E/AndroidRuntime(1550): Process: com.example.simplifimed, PID: 1550 06-20 09:23:26.996: E/AndroidRuntime(1550): java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ListView.setAdapter(android.widget.ListAdapter)' on a null object reference 06-20 09:23:26.996: E/AndroidRuntime(1550): at com.example.simplifimed.Tab2$LoadAllContacts$1.run(Tab2.java:256) 06-20 09:23:26.996: E/AndroidRuntime(1550): at android.app.Activity.runOnUiThread(Activity.java:5293) 06-20 09:23:26.996: E/AndroidRuntime(1550): at com.example.simplifimed.Tab2$LoadAllContacts.onPostExecute(Tab2.java:245) 06-20 09:23:26.996: E/AndroidRuntime(1550): at com.example.simplifimed.Tab2$LoadAllContacts.onPostExecute(Tab2.java:1) 06-20 09:23:26.996: E/AndroidRuntime(1550): at android.os.AsyncTask.finish(AsyncTask.java:636) 06-20 09:23:26.996: E/AndroidRuntime(1550): at android.os.AsyncTask.access$500(AsyncTask.java:177) 06-20 09:23:26.996: E/AndroidRuntime(1550): at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:653) 06-20 09:23:26.996: E/AndroidRuntime(1550): at android.os.Handler.dispatchMessage(Handler.java:102) 06-20 09:23:26.996: E/AndroidRuntime(1550): at android.os.Looper.loop(Looper.java:135) 06-20 09:23:26.996: E/AndroidRuntime(1550): at android.app.ActivityThread.main(ActivityThread.java:5257) 06-20 09:23:26.996: E/AndroidRuntime(1550): at java.lang.reflect.Method.invoke(Native Method) 06-20 09:23:26.996: E/AndroidRuntime(1550): at java.lang.reflect.Method.invoke(Method.java:372) 06-20 09:23:26.996: E/AndroidRuntime(1550): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903) 06-20 09:23:26.996: E/AndroidRuntime(1550): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)

The tab2.xml is,

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
<!-- Main ListView 
     Always give id value as list(@android:id/list)
-->
<ListView
    android:id="@android:id/list"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"/>

</LinearLayout>

and list_item.xml is as follows,

 <?xml version="1.0" encoding="utf-8"?>
 <!-- Layout for individual news entries in a list -->
 <TableLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:id="@+id/tableLayout1"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent" >

<TableRow
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:padding="5dip" >

    <!-- Product id (pid) - will be HIDDEN - used to pass to other activity -->
    <TextView
    android:id="@+id/pid"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:visibility="gone" />

    <!-- Name Label -->
    <TextView
    android:id="@+id/name"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:paddingTop="6dip"
    android:paddingLeft="6dip"
    android:textSize="17dip"
    android:textStyle="bold" /> 

    <!-- type Label -->
    <TextView
    android:id="@+id/type"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:paddingTop="6dip"
    android:paddingLeft="6dip"
    android:textSize="17dip"
    android:textStyle="bold" />                         

 </TableRow>

</TableLayout>

Try to debug and verify that are you getting an Object at lv = (ListView) v.findViewById(R.id.list); this line? — Rajan Bhavsar
hi rajan, i have tried adding Log.d("List view: ", lv.toString()); after above line but it is not showing in log cat any where.I am using sliding tabs and this is the second tab fragment code so this tab is not loaded first..may be because of that it not showing..how can i check that? — SK IRT
If you are not get any Object reference for ListView Object then You are getting this Error. For that First you need to load your view in fragment correctly — Rajan Bhavsar
View v = inflater.inflate(R.layout.tab2,container,false); this should do that right? — SK IRT
Please Post the code for tab2 layout xml file and yes for your above comment — Rajan Bhavsar

Rajan Bhavsar Rajan Bhavsar · Accepted Answer · 2015-06-20T04:48:57

Hi Please Try extend your Fragment by replacing with ListFragment. Suc has Follows:

public class MyListFragment extends ListFragment

In Your case as follows :

public class Tab2 extends ListFragment

Now you are able to get the ListView.

OR

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">

<ListView
 android:id="@+id/list"
android:layout_width="fill_parent"
android:layout_height="wrap_content"/>
</LinearLayout>

Android setadapter Null pointer

1 Answers