list.add上的NullPointerException [英] NullPointerException on list.add

问题描述

我在 modelData.add(i，es)方法中得到了 NullPointerException .通过调试，我知道 es 不是 null .我真的很困惑，谢谢.

I am getting a NullPointerException at the modelData.add(i, es) method. I know from debugging that es isn't null. I'm really confused, thanks.

public class EventTableModel extends AbstractTableModel {

    //private int rowCount = 0;
    protected List<EventSeat> modelData;
    private static final int COLUMN_COUNT = 3;
    private Event e;
    Event j = GUIpos.m;
    int i = 1;

public EventTableModel(Event e) {
    this.e = e;
    try {
        System.out.println(modelData);
        for (EventSeat es : e.getEventSeats()) {
            modelData.add(i, es);
            i++;
        }
    } catch (DataException ex) {
        Logger.getLogger(EventTableModel.class.getName()).log(Level.SEVERE, null, ex);
    }

}

推荐答案

您需要初始化一个List才能获取 NullPointerException .

You need to initialize a List to not get the NullPointerException.

protected List<EventSeat> modelData = new ArrayList<EventSeat>();

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