Question

In my android app, I have one Activity and more java class which is not an activity.
So there is a get method in this other java class, which returns an Object. This method starts a new thread to gets the data and attaches it with the object

Now I am calling this get method in my Activity to get that object. I am doing something like this –

mNewsList = new ArrayList<NewsContentManager.NewsPojo>();
mNewsList = manager.getNewsList();

and the method is this -

    public ArrayList<NewsPojo> getNewsList() {
        Log.v("TAG", ""+newsList);
        if(newsList == null)
        {
            Thread t = new Thread(){
                public void run(){

                    Log.v("TAG", "Inside run");

                    np1 = new NewsPojo();
                    np1.setTitle("A");
                    np1.setDescription("dhghfdklsa");


                    np2 = new NewsPojo();
                    np2.setTitle("B");
                    np2.setDescription("dhghfdklsa");


                    np3 = new NewsPojo();
                    np3.setTitle("c");
                    np3.setDescription("dhghfdklsa");

                    newsList = new ArrayList<NewsPojo>();

                    Log.v("in run",""+newsList);

                    newsList.add(np1);
                    newsList.add(np2);
                    newsList.add(np3);

                    Log.v("in run",""+newsList.size());

                    setNewsList(newsList);

                    handler.sendEmptyMessage(0);

                }// end of run
            };// end of thread
            t.start();
        }//end of if

        return newsList;
    }

But I am getting nullPointer Exception in my Activity.
If I remove Thread from this method then it works correctly.
What should I do ?

Thanks

Answer 1

Additionally to my comment to your question.

First, try to avoid using Threads in such a way. Use AsyncTask instead.
On it’s preExecute show some dialog to the user, that you are loading a list, on it’s doInBackground put your logic that will return new list, and in postExecute just dismiss the dialog and proceed.