Object is null set in Defalut add Card in Arraylist

Question

I create Default class with see list Cart in all app

 public class Default extends Application {

 public ArrayList<Card> listCard;

        public ArrayList<Card> getListCard() {
            return listCard;
        }

        public void setListCard(ArrayList<Card> listCard) {
            this.listCard = listCard;
        }

    }

Next when

public class ScanQrCodeActivity extends AppCompatActivity {

     private ArrayList<Card> cardList;

....

                    if (hotpValue.equals(passwordHotp)) {

                        Card card = new Card(path3, base32, nameCard, intervalTotp, passwordHotp, getDate(), expirationDate, hotpValue);

                      Default app = (Default) getApplicationContext();
                            cardList = app.getListCard();
                            cardList.add(card); // show error line code 
                            app.setListCard(cardList);
                            cardList = new ArrayList<Card>();
                            cardList= app.getListCard();
                            System.out.println("Dodanokarte"+card.getNameCard());

                    }

see log

Process: com.novum.smrtkarta, PID: 13844 java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.util.ArrayList.add(java.lang.Object)' on a null object reference at com.xxxx.smrtkarta.activity.ScanQrCodeActivity$3$1.run(ScanQrCodeActivity.java:277) at android.os.Handler.handleCallback(Handler.java:739) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:148) at android.app.ActivityThread.main(ActivityThread.java:5417) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

What I do wrong ?

Possible duplicate of [What is a NullPointerException, and how do I fix it?](http://stackoverflow.com/questions/218384/what-is-a-nullpointerexception-and-how-do-i-fix-it) — AxelH, May 04 '17 at 11:54

score 2 · Answer 1 · answered Apr 07 '17 at 07:48

2

Here cardList is null. Make sure that you have initialized the listCard in Default class before calling getListCard method

answered Apr 07 '17 at 07:48

stinepike

54,068
14
92
112

score 1 · Accepted Answer · answered Apr 07 '17 at 07:49

1

This should work you have to change Change:

ArrayList<Card> listCard

to:

ArrayList<Card> list = new ArrayList<Card>;

answered Apr 07 '17 at 07:49

JakSok

124
4

change this line in class Defult ? – Ewelina Apr 07 '17 at 07:58

Object is null set in Defalut add Card in Arraylist

2 Answers2

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