Populating listview with parse cloud objects on Android Studio(Using adapter)

Question

I have some problem with my code and I just can't find a solution. Here's my project: I have a Parse database that stores users, and these users can post status. On my parse app I have two classes, users and status. When some user upload the status, I save them and the username. The problem is, I can't retrieve the values from 'status' on parse and show on a listview:

ParseQuery<ParseObject> query = new ParseQuery<ParseObject>("Status");
        query.findInBackground(new FindCallback<ParseObject>() {
            @Override
            public void done(List<ParseObject> status, ParseException e) {
                if(e == null) {
                    mStatus = status;
                    listview tcam = new listview();
                    tcam.mac(mStatus);

                }else{
                    System.out.println("Deu ruim");
                }
            }
        });

    }

mStatus is declared like this: List<ParseObject> mStatus; , listview is another java class, and mac is a method(and that's where the problem is). I need to pass mStatus as parameter, so I can use on this method(on listview.java):

public void mac(List<ParseObject> mStatus){
        StatusAdapter adapter = new StatusAdapter(getListView().getContext(), mStatus);
        setListAdapter(adapter);
    }

I get an error on the following lines:

(StatusAdapter adapter = new StatusAdapter(getListView().getContext(), mStatus));

and

(tcam.mac(mStatus);)

and the application closes.

I've tested the variable mStatus and it is not empty. You may ask why I'm doing this in 2 classes, and it is because the ...getListView().getContext()... doesn't work without extending ListActivity, and I'm already extending AppCompactActivity.(This is the only solution I found)

StatusAdapter is another class, and I have extended ArrayAdapter<ParseObject>. And yes, I have a xml layout file to draw my listview...

Thanks!

That's my console error:

12-11 16:48:56.545 22535-22535/com.example.rafael.whatsnew W/dalvikvm: threadid=1: thread exiting with uncaught exception (group=0x4184c7d0)
12-11 16:48:56.555 22535-22535/com.example.rafael.whatsnew E/AndroidRuntime: FATAL EXCEPTION: main
java.lang.NullPointerException
  at android.app.Activity.setContentView(Activity.java:1893)
  at android.app.ListActivity.ensureList(ListActivity.java:312)
  at android.app.ListActivity.getListView(ListActivity.java:297)
  at com.example.rafael.whatsnew.listview.mac(listview.java:21)
  at com.example.rafael.whatsnew.home$4.done(home.java:204)
  at com.example.rafael.whatsnew.home$4.done(home.java:198)
  at com.parse.ParseTaskUtils$2$1.run(ParseTaskUtils.java:115)
  at android.os.Handler.handleCallback(Handler.java:615)
  at android.os.Handler.dispatchMessage(Handler.java:92)
  at android.os.Looper.loop(Looper.java:137)
  at android.app.ActivityThread.main(ActivityThread.java:5031)
  at java.lang.reflect.Method.invokeNative(Native Method)
  at java.lang.reflect.Method.invoke(Method.java:511)
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:792)
  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:555)
  at dalvik.system.NativeStart.main(Native Method)

Well, it's a null pointer: http://stackoverflow.com/questions/218384/what-is-a-null-pointer-exception-and-how-do-i-fix-it — Deividi Cavarzan, Dec 11 '15 at 19:01
probrably `getListView` is returning `null`. Did you debug this code? — Deividi Cavarzan, Dec 11 '15 at 19:03
I'm reading the null pointer exception... Yes, i did debug and `getListView `is not `null` — Macaroni and not cheese, Dec 11 '15 at 19:09
This: `StatusAdapter adapter = new StatusAdapter(getListView().getContext(), mStatus);` — Macaroni and not cheese, Dec 11 '15 at 19:16
If `getListView()` is throwing null. check it again, it's what stacktrace is telling: `java.lang.NullPointerException at android.app.ListActivity.getListView(ListActivity.java:297)` — Deividi Cavarzan, Dec 11 '15 at 19:22
Hmmm assuming that `getListView()` is throwing null, what would the solution be? — Macaroni and not cheese, Dec 11 '15 at 19:55

Populating listview with parse cloud objects on Android Studio(Using adapter)

0 Answers0