java.lang.NullPointerException : on android.widget.EditText.addTextchangedlistener

Question

I am working on android app and put filtration functionality on Listview. But I got below error:

java.lang.RuntimeException: Unable to start activity componentInfo:java.lang.NullPointerException: Attempt to invoke virtual method void android.widget.EditText.addTextchangedListener(android.text.TextWatcher) on a Null object Reference

Below is my code.

  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.shopdetail);
    aq=new AQuery(this);
    value=5;


                GPSTracker  gps = new GPSTracker(Shopdetail.this);
                    if(gps.canGetLocation()){
                        double latitude = gps.getLatitude();
                        double longitude = gps.getLongitude();
                         getdatalatlog(latitude,longitude);                     
                   }else{
                        gps.showSettingsAlert();
                    }                       
                    Intent openStartingPoint=getIntent();
                    String city=openStartingPoint.getStringExtra("spinnerText");
                    bindcity(city);

            final EditText inputSearch = (EditText)findViewById(R.id.inputSearch);                      
                    inputSearch.addTextChangedListener(new TextWatcher() {

                        @Override
                        public void onTextChanged(CharSequence cs, int arg1, int arg2, int arg3) {
                            // When user changed the Text
                            //Shopdetail.this.adapter.getFilter().filter(cs);  
                            //((SimpleAdapter)Shopdetail.this.adapter).getFilter().filter(cs); 

                          //  ((SimpleAdapter)getListAdapter()).getFilter().filter(cs); 

                            //get the text in the EditText
                                                                                     EditText inputSearch =    (EditText)findViewById(R.id.inputSearch);
                             String searchString=inputSearch.getText().toString();
                               int textLength=searchString.length();
                               searchResults.clear();

                               for(int i=0;i<mCommentList.size();i++)
                               {
                              String shopName=mCommentList.get(i).get(TAG_TITLE).toString();
                              if(textLength<=shopName.length()){
                              //compare the String in EditText with Names in the ArrayList
                                 if(searchString.trim().equalsIgnoreCase(shopName.trim().substring(0,textLength))){
                                searchResults.add(mCommentList.get(i));

                                getdata();}
                              }
                               }

                               adapter.notifyDataSetChanged();
                        }

                        @Override
                        public void beforeTextChanged(CharSequence arg0, int arg1, int arg2,
                                int arg3) {
                            // TODO Auto-generated method stub

                        }

                        @Override
                        public void afterTextChanged(Editable arg0) {
                            // TODO Auto-generated method stub                          
                        }
                    });       
    }

        private void getdata() {
    // TODO Auto-generated method stub
    String[] data = new String[]{TAG_TITLE,TAG_USERNAME ,TAG_CONTACT ,TAG_MESSAGE ,TAG_LATITUDE , TAG_LONGITUDE };

    int[] to= new int[] {R.id.shop_name,R.id.address,R.id.contact,R.id.distance,R.id.latitude,R.id.longitude};

    final   SimpleAdapter  adapter = new SimpleAdapter(this, mCommentList,R.layout.single_post, data,to);

     ListView lv = ( ListView ) findViewById(android.R.id.list);
     lv.setAdapter(adapter);

}

Below is my code to firstly bind data.

    private void getdatalatlog(double latitude, double longitude) {
        // TODO Auto-generated method stub
        //value=5;
        String url = "http://192.168.2.4/PHP/webservice/comments.php?latitude='"+latitude+"'&longitude='"+longitude+"'&value='"+value+"'";
        aq.progress(R.id.progressBar1).ajax(url, JSONObject.class, this,"jsonCallback");

    }

    @SuppressWarnings("unchecked")
    public void jsonCallback(String url, JSONObject json, AjaxStatus status) {  


        if (json != null) { 


        List<String> city = new ArrayList<String>();
        mCommentList = new ArrayList<HashMap<String, Object>>();

            Gson gson = new GsonBuilder().create();
            try {

             JSONArray jsonResponse = json.getJSONArray("posts");
                city = gson.fromJson(jsonResponse.toString(),List.class);
                for (int i = 0; i < jsonResponse.length(); i++) {
                    JSONObject c = jsonResponse.getJSONObject(i);       

                    String title = c.getString(TAG_TITLE);
                    String content = c.getString(TAG_MESSAGE);
                    String username = c.getString(TAG_USERNAME);
                    String lat = c.getString(TAG_LATITUDE);
                    String log = c.getString(TAG_LONGITUDE);
                    String cont = c.getString(TAG_CONTACT);

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

                    map.put(TAG_TITLE, title);
                    map.put(TAG_MESSAGE, content);
                    map.put(TAG_USERNAME, username);
                    map.put(TAG_LATITUDE, lat);
                    map.put(TAG_LONGITUDE, log);
                    map.put(TAG_CONTACT, cont);
                        // adding HashList to ArrayList
                mCommentList.add(map);

                searchResults=new ArrayList<HashMap<String,Object>>(mCommentList);
                //HashMap<String, String> map1 = new HashMap<String, String>();
                //map1.put(TAG_TITLE, title);
                //sortdata;


                }
            } 
            catch (JSONException e) {

                Toast.makeText(aq.getContext(), "Error in parsing JSON", Toast.LENGTH_LONG).show();
            }
            catch (Exception e) {
                Toast.makeText(aq.getContext(), "Something went wrong", Toast.LENGTH_LONG).show();
            }


            String[] data = new String[]{TAG_TITLE,TAG_USERNAME ,TAG_CONTACT ,TAG_MESSAGE ,TAG_LATITUDE , TAG_LONGITUDE };

            int[] to= new int[] {R.id.shop_name,R.id.address,R.id.contact,R.id.distance,R.id.latitude,R.id.longitude};

            final   SimpleAdapter  adapter = new SimpleAdapter(this, mCommentList,R.layout.single_post, data,to);

             ListView lv = ( ListView ) findViewById(android.R.id.list);
             lv.setAdapter(adapter);




            lv.setOnItemClickListener(new OnItemClickListener() {

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

                    Intent intent = new Intent();
                     Bundle b = new Bundle();


                     String name= ((TextView) view.findViewById(R.id.shop_name)).getText().toString()+" , "+((TextView) view.findViewById(R.id.contact)).getText().toString();

                     String lati= ((TextView) view.findViewById(R.id.latitude)).getText().toString();

                     String longi= ((TextView) view.findViewById(R.id.longitude)).getText().toString();

                     b.putString("shop",name);
                     b.putString("lati",lati);
                     b.putString("long",longi);
                    intent.setClass(Shopdetail.this, Mapview.class);
                    intent.putExtras(b);
                    startActivity(intent);
                }
            });     
    } 
}

When user type letter on EditText the data is filtered and its bind in listview according to that. Its not working. Please guide me.

Thanks so much in advance.

Answer 1

Invoking method on Null object reference will always throw java.lang.NullPointerException.

In your case, logs clearly indicate "Attempt to invoke method addTextchangedListener(android.text.TextWatcher) on a Null object Reference".

In short - inputSearch is null and should be initialized before any method invocations.

Answer 2

You forget to initialized inputSearch

inputSearch=(EditText)findViewById(R.id.editTextId);

OR move

 EditText inputSearch = (EditText)findViewById(R.id.inputSearch);

before

 inputSearch.addTextChangedListener(new TextWatcher() {