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Posted October 10, 2014 6:52am by

Please help! It keeps saying your blog reader has stopped

I have watched the videos again and again thinking that I have made a mistake, but still occurring.! I dont know what to do ?

October 10, 2014 7:19am

Try doing a clean build (Project > Clean).

October 10, 2014 8:42am

Hi Timmy

It is impossible to identify the problem without some more input from you unfortunately. Can you please post your Logcat entries here so we can see where the code cause an error and fails. Hopefully then we can direct you by looking at some source code of yours which would also need to be posted here.

Thanks Daniel

October 12, 2014 6:44am

            <p>package mydsigncommunityblog.blogreader;

import android.app.AlertDialog;
import android.app.ListActivity;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.AsyncTask;
import android.os.Bundle;
import android.text.Html;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ProgressBar;
//import android.widget.TextView;
import android.widget.Toast;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;


public class MainListActivity extends ListActivity {

    protected String[] mBlogPostTitles;
    public static final int NUMBER_OF_POSTS = 20;
    public static final String TAG = MainListActivity.class.getSimpleName();
    protected JSONObject mBlogData;
    protected ProgressBar mProgressBar;

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

       mProgressBar = (ProgressBar) findViewById(R.id.progressBar2);

        if(isNetworkAvailable()) {
            mProgressBar.setVisibility(View.VISIBLE);
            GetBlogPostsTask getBlogPostsTask = new GetBlogPostsTask();
            getBlogPostsTask.execute();

        }
        else
        {
            Toast.makeText(this, "Network is unavailable!", Toast.LENGTH_LONG).show();
           // TextView emptyTextView = (TextView) getListView().getEmptyView();
           // emptyTextView.setText(getString(R.string.no_items));
        }


        // String message = getString(R.string.no_items);
        //Toast.makeText(this,message,Toast.LENGTH_LONG).show()




    }

    private boolean isNetworkAvailable() {

        ConnectivityManager manger = (ConnectivityManager)
                getSystemService(CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = manger.getActiveNetworkInfo();
        boolean isAvailable = false;
        if(networkInfo != null && networkInfo.isConnected())
        {
            isAvailable = true;
        }
        else
        {
            try {
                Log.d(TAG, mBlogData.toString(2));
            } catch (JSONException e) {
                Log.e(TAG, "Exception caught", e);
            }
        }
        return isAvailable;
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main_list, menu);
        return true;
    }
    private void handleBlogResponse()
    {
        mProgressBar.setVisibility(View.INVISIBLE);
        if(mBlogData == null)
        {
            updateDisplayForError();


        }
        else
        {
            try {
                JSONArray jsonPosts = mBlogData.getJSONArray("posts");
                mBlogPostTitles = new String[jsonPosts.length()];
                for(int i=0; i < jsonPosts.length(); i++)
                {
                    JSONObject post = jsonPosts.getJSONObject(i);
                    String title = post.getString("title");
                    title = Html.fromHtml(title).toString();
                    mBlogPostTitles[i] = title;

                }
                ArrayAdapter<String>adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,
                        mBlogPostTitles);
                setListAdapter(adapter);
            } catch (JSONException e)
            {
              Log.e(TAG, "Exception caught!", e);
            }
        }


         }

    private void updateDisplayForError() {
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setTitle(getString(R.string.error_title));
        builder.setMessage(getString(R.string.error_message));
        builder.setPositiveButton(android.R.string.ok,null);
        AlertDialog dialog = builder.create();
        dialog.show();

        //TextView emptyTextView = (TextView)getListView().getEmptyView();
        //emptyTextView.setText(getString(R.string.no_items));
    }

    private class GetBlogPostsTask extends AsyncTask<Object,Void,JSONObject>
    {

    @Override

    protected JSONObject doInBackground(Object... arg0) {
        int responseCode =-1;
        JSONObject jsonResponse = null;
        try {
            URL blogFeedUrl = new URL("http://blog.teamtreehouse.com/api/get_recent_summary/?count=" + NUMBER_OF_POSTS);
            HttpURLConnection connection = (HttpURLConnection) blogFeedUrl.openConnection();
            connection.connect();
             responseCode = connection.getResponseCode();
            if(responseCode == HttpURLConnection.HTTP_OK)
            {
                InputStream inputStream = connection.getInputStream();
                Reader reader = new InputStreamReader(inputStream);
                int contentLength = connection.getContentLength();
                char [] charArray = new char[contentLength];
                reader.read(charArray);
                String responseData = new String(charArray);
                 jsonResponse = new JSONObject(responseData);


            }
            else
            {
                Log.i(TAG, "Unsuccessful code response!  " + responseCode);

            }

        }
        catch (MalformedURLException e)
        {
            Log.e(TAG, "Exception caught", e);
        } catch (IOException e)
        {
            Log.e(TAG, "Exception caught", e);
        } catch (Exception e)
        {
            Log.e(TAG, "Exception caught", e);

        }

        return  jsonResponse;


    }

        @Override
        protected void onPostExecute(JSONObject result) {
            mBlogData = result;
            handleBlogResponse();


        }



}




}</p>
            ```

October 12, 2014 6:45am

Daniel Hartin Thank you for the quick response and sorry for the late reply

I have put the code and the log if you could help me Rally appreciate it

October 12, 2014 6:47am

            <p>10-10 12:26:01.571    1232-1232/mydsigncommunityblog.blogreader D/AndroidRuntime﹕ Shutting down VM
10-10 12:26:01.571    1232-1232/mydsigncommunityblog.blogreader W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0xa4c3c648)
10-10 12:26:01.575    1232-1232/mydsigncommunityblog.blogreader E/AndroidRuntime﹕ FATAL EXCEPTION: main
    java.lang.RuntimeException: Unable to start activity ComponentInfo{mydsigncommunityblog.blogreader/mydsigncommunityblog.blogreader.MainListActivity}: java.lang.NullPointerException
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2211)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
            at android.app.ActivityThread.access$600(ActivityThread.java:141)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
            at android.os.Handler.dispatchMessage(Handler.java:99)
            at android.os.Looper.loop(Looper.java:137)
            at android.app.ActivityThread.main(ActivityThread.java:5103)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:525)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
            at dalvik.system.NativeStart.main(Native Method)
     Caused by: java.lang.NullPointerException
            at mydsigncommunityblog.blogreader.MainListActivity.onCreate(MainListActivity.java:46)
            at android.app.Activity.performCreate(Activity.java:5133)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2175)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
            at android.app.ActivityThread.access$600(ActivityThread.java:141)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
            at android.os.Handler.dispatchMessage(Handler.java:99)
            at android.os.Looper.loop(Looper.java:137)
            at android.app.ActivityThread.main(ActivityThread.java:5103)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:525)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
            at dalvik.system.NativeStart.main(Native Method)
</p>
            ```

October 12, 2014 6:49am

ogechi1

Thank you for your response. I tried doing clean project and same thing still occurring .

October 25, 2014 2:40am

Daniel Hartin Thanks a lot Sorry for late reply I had midterm exams.

3 Answers

October 12, 2014 5:57pm

Hi Timmy

Sorry I haven't got back sooner, I've been busy over the weekend.

It looks to me as if in your onCreate() method you haven't called the method setcontentView() (You may have accidentally deleted this). Without this call to setContentView your code is breaking when it tries to assign the mProgressBar variable as there is no XML for it to look at so it results in a nullPointerException.

Add the line in as the code below shows simply replacing the xml layout name for your own layout.

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.your_xml_layout_filename_here);

Hope this helps

Daniel

October 13, 2014 11:38am

Daniel Hartin

Thanks a lot . It really helps and works directly after i did that. But i still get an empty list i mean i dont get the data from the JSON as it used to do before. It might be my mistake because I honestly dont know what is the xml layout name i should choose. I selected main_activity _list Sorry for such a question

P.S. I also dont know why the progress bar keeps loading for ever, I tried to look over the code again and i couldnt figure it out. it's ok for this ...More importantly i need to understand the things i got above

Thanks million

here is my xml file

            <p><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    tools:context=".MainListActivity">

    <TextView

        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_alignParentEnd="true"
        android:text="@string/no_items"
        android:id="@android:id/empty" />






    <ListView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@android:id/list"
        android:layout_alignParentRight="true"
        android:layout_alignParentEnd="true" />

    <ProgressBar
        style="?android:attr/progressBarStyleLarge"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/progressBar2"

        android:layout_centerInParent="true" />


</RelativeLayout>
</p>
            ```

October 13, 2014 11:59am

Hi Timmy

It looks as if your XML file is okay. If it is not showing an error now then the problem is not with your code as such.

I have posted the URL address into a browser and get the response JSON data back so that is correct.

When you say the progressBar loads forever, do you mean it loads forever (never ends) or does it just take a long time?.

Are you testing this on an emulator or on an actual device?

Thanks Daniel

October 13, 2014 1:45pm

Daniel Hartin

It loads forever never ends

even when I try to delete the progress bar just to see if the information will load or not i got that message i have typed which says 'Empty' and please for setContentView(R.layout.your_xml_layout_filename_here); I dont know with what I should replace it

thanks again

October 13, 2014 2:03pm

Hi Timmy

The line below needs changing to the name of the XML file you pasted above. In the project explorer inside Eclipse open up your app, then go into the res folder, then open up layout folder, all your layouts should be in here! where you click on the file to open it the name will be displayed simply replace the name with the name of your file. I have changed the name in the lines below so you can see which code needs changing.

Sorry I can't help you anymore than that without physically seeing your screen.

setContentView(R.layout.your_xml_layout_filename_here);

//You only need to change the last part
//The line below changes the XML file name 
//You will need to find your own using the path explained above

setContentView(R.layout.main_layout);

As for the ASyncTask i'm not sure your code looks okay to me. Have you tried looking in the log? You have various calls to the log setup for an incorrect response from the URL address. I would run the app. It must be breaking before the call to handleBlogResponse() as the mProgressBar is not being set to Invisible, so the ASynctask class has the problem. All the lines below are calls to the log I assume the code is catching an exception but because there is only a call to your log file nothing happens. Look in your log file and paste here what happens (note it may be worth changing the strings to the values below just to see a bit easier).

else
            {
                Log.i(TAG, "Unsuccessful code response!  " + responseCode);

            }

        }
        catch (MalformedURLException e)
        {
            Log.e(TAG, "MALFORMED Exception caught", e);
        } catch (IOException e)
        {
            Log.e(TAG, "IO Exception caught", e);
        } catch (Exception e)
        {
            Log.e(TAG, "ANOTHER Exception caught", e);

January 19, 2016 1:54pm

I'm having a problem answering this challenge.

The challenge is, Create a new variable jsonObject and then use the native JSON object to parse the jsonString and assign it to jsonObject.

Here is the code provided; var jsonString = '{"name": "Andrew", "languages": ["javascript", "swift", "java", "ruby", "html", "css", "qbasic"]}';

My answer was; var jsonObject = JSON.parse("jsonString");

But I get an error.

January 20, 2016 9:53am

Hi Leroy

You really need to ask this in another new question to get the best response as this question is over a year old and has been answered already.

I can try and help in a new question.

Thanks Daniel

February 8, 2016 8:14pm

var jsonObject = JSON.parse(jsonString);
That is the answer that works.............................

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Please help! It keeps saying your blog reader has stopped

ogechi1

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Daniel Hartin

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3 Answers

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Daniel Hartin

Timmy Yong

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Daniel Hartin

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Timmy Yong

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Daniel Hartin

Daniel Hartin

Leroy Sibisi

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