[英]NullPointerException on list.add
I am getting a NullPointerException
at the modelData.add(i, es)
method. 我在
modelData.add(i, es)
方法中得到NullPointerException
。 I know from debugging that es
isn't null
. 我从调试中知道
es
不是null
。 I'm really confused, thanks. 我真的很困惑,谢谢。
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);
}
}
您需要初始化List以不获取NullPointerException
。
protected List<EventSeat> modelData = new ArrayList<EventSeat>();
尝试
protected List<EventSeat> modelData = new ArrayList<EventSeat>();
On the first look, seems like modelData has not been instantiated. 在第一眼看来,似乎modelData尚未实例化。 I would instantiate the modelData like:
我将实例化modelData,如:
protected List<EventSeat> modelData = new ArrayList<EventSeat>();
FYI.. In Java 7 there will be a new syntax you can use- someObject?.doSomething();
仅供参考。在Java 7中,您可以使用一种新的语法 -
someObject?.doSomething();
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.