CODEWITHSUNDEEP
javaandroid
Nitish Chopra
Nitish Chopra

Reputation: 273

Unfortunately My App has Stopped working due to nullPointerException

I am trying to get images from the server and load them into gridview but My App is not responding.I am using picasso library to load the images.

This is my ImageAdapter class

package com.example.haha;

public class ImageAdapter extends BaseAdapter {

    private Context context;

    int length;
    String[] poster_paths=null;

    public ImageAdapter(Context c) {
        context = c;
        new BackgroundTask().execute();
    }

    public int getCount(){
        return length;
        }

    public Object getItem(int position) {
        return null;
    }

    public long getItemId(int position) {
        return 0;
    }

    public View getView(int position, View convertView, ViewGroup parent){
        //ImageView image;
        LayoutInflater inflater = (LayoutInflater) context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        if(convertView==null)
        convertView=(ImageView)inflater.inflate(R.layout.gridviewitem, null);



        Picasso.with(context)  //USING PICASSO LIBRARY
        .load("http://image.tmdb.org/t/p/w185/"+ poster_paths[position]) 
        .placeholder(R.drawable.ic_launcher)
        .into((ImageView)convertView);

        return convertView;
    }


    public class BackgroundTask extends AsyncTask<String, Void, String[]>{


        final String BASE_URL="http://api.themoviedb.org/3/discover/movie?"
                + "sort_by=popularity.desc&api_key=b6c282dc7fb604515fdcf8d8cf56e761";


         private String[] jsonParse(String movieJsonStr) throws JSONException{

            final String POSTER_PATH="poster_path";  //JSON STRING PARSING AND RETURN 
                                                     //POSTER PATHS

            JSONObject jsonObj=new JSONObject(movieJsonStr);
            JSONArray resultArray= jsonObj.getJSONArray("results");

            length=resultArray.length();
            String[] poster_paths= new String[length];
            for(int i=0;i<length;i++){
                poster_paths[i]=resultArray.getJSONObject(i).getString(POSTER_PATH);
            }

            for(String res : poster_paths)
            Log.v(POSTER_PATH, res);    

            return poster_paths;
        }


        @Override
        protected String[] doInBackground(String... params) {

            String movieJsonStr = null;

            BufferedReader reader = null;
            HttpURLConnection urlConnection = null; // READ THE INPUTSTREAM AND
                                                    // GET THE JSONSTRING
            try {
                URL url = new URL(BASE_URL);
                urlConnection = (HttpURLConnection) url.openConnection();
                urlConnection.setRequestMethod("GET");
                urlConnection.connect();

                // Read the input stream into a String
                InputStream inputStream = urlConnection.getInputStream();
                StringBuffer buffer = new StringBuffer();
                if (inputStream == null) {
                    // Nothing to do.
                    return null;
                }

                reader = new BufferedReader(new InputStreamReader(inputStream));

                String line;
                while ((line = reader.readLine()) != null) {
                    // Since it's JSON, adding a newline isn't necessary (it
                    // won't affect parsing)
                    // But it does make debugging a *lot* easier if you print
                    // out the completed
                    // buffer for debugging.
                    buffer.append(line + "\n");
                }

                if (buffer.length() == 0) {
                    // Stream was empty. No point in parsing.
                    return null;
                }

                movieJsonStr = buffer.toString();
                Log.v("Movie string: ", movieJsonStr);
            } catch (Throwable e) {
                Log.e("backgroundtask", "EXCEPTION", e);
            } finally {
                urlConnection.disconnect();
                try {
                    reader.close();
                } catch (IOException e) {
                    Log.e("READER.CLOSE()", e.toString());
                }
            }

            try {
                return jsonParse(movieJsonStr);
            } catch (JSONException e) {
                Log.e("BACKGROUNDTASK", "EXCEPTION FROM jsonParse()", e);
            }

            return null;
        }

        @Override
        protected void onPostExecute(String[] result) {
            if(result!=null)
            poster_paths=result;
            }

        }

}

and this is my logcat

08-01 03:04:56.108: D/AndroidRuntime(2588): Shutting down VM
08-01 03:04:56.108: E/AndroidRuntime(2588): FATAL EXCEPTION: main
08-01 03:04:56.108: E/AndroidRuntime(2588): Process: com.example.haha, PID: 2588
08-01 03:04:56.108: E/AndroidRuntime(2588): java.lang.NullPointerException: Attempt to read from null array
08-01 03:04:56.108: E/AndroidRuntime(2588):     at com.example.haha.ImageAdapter.getView(ImageAdapter.java:62)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.widget.AbsListView.obtainView(AbsListView.java:2344)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.widget.GridView.onMeasure(GridView.java:1060)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.view.View.measure(View.java:17430)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.view.View.measure(View.java:17430)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.support.v7.internal.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:124)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.view.View.measure(View.java:17430)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.support.v7.internal.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:444)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.view.View.measure(View.java:17430)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.view.View.measure(View.java:17430)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.widget.LinearLayout.measureVertical(LinearLayout.java:722)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.widget.LinearLayout.onMeasure(LinearLayout.java:613)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.view.View.measure(View.java:17430)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2560)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.view.View.measure(View.java:17430)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2001)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1166)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1372)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1054)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5779)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.view.Choreographer$CallbackRecord.run(Choreographer.java:767)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.view.Choreographer.doCallbacks(Choreographer.java:580)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.view.Choreographer.doFrame(Choreographer.java:550)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:753)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.os.Handler.handleCallback(Handler.java:739)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.os.Handler.dispatchMessage(Handler.java:95)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.os.Looper.loop(Looper.java:135)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at android.app.ActivityThread.main(ActivityThread.java:5221)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at java.lang.reflect.Method.invoke(Native Method)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at java.lang.reflect.Method.invoke(Method.java:372)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
08-01 03:04:56.108: E/AndroidRuntime(2588):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
08-01 03:04:56.109: W/ActivityManager(1226):   Force finishing activity com.example.haha/.Main
08-01 03:04:56.110: W/ActivityManager(1226):   Force finishing activity com.example.haha/.MainActivity

the logcat is saying that there is a nullpointerException while accessing the string array poster_paths in getView method as it is a null array but in the postexecute method the poster_paths array is assigned the strings Please help....

Upvotes: 0

Views: 309

Answers (1)

Reimeus
Reimeus

Reputation: 159804

Youre shadowing the variable poster_paths. Replace

String[] poster_paths= new String[length];

with

posterPaths = new String[length];

Upvotes: 4

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