Firebase crashlytics 仅报告几次“尝试在空对象引用上调用虚拟方法 '(java.lang.String)'”

如何解决Firebase crashlytics 仅报告几次“尝试在空对象引用上调用虚拟方法 '(java.lang.String)'”

如你所见，我试图控制该值不为空，但同样的，错误报告仍然到达。但他们很少。

错误

Caused by java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String package...Token.getValor()' on a null object reference
   at ...NotificationListPresenter.obtainNotifications(NotificationListPresenter.java:2)
   at ...ListActivity.obtainNotifications(ListActivity.java:23)
   at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1454)
   at android.app.Activity.performResume(Activity.java:8111)
   at android.app.ActivityThread.performResumeActivity(ActivityThread.java:4647)
   at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:4690)
   at android.app.servertransaction.ResumeActivityItem.execute(ResumeActivityItem.java:52)
   at android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:176)
   at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:97)
   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2267)
   at android.os.Handler.dispatchMessage(Handler.java:107)
   at android.os.Looper.loop(Looper.java:237)
   at android.app.ActivityThread.main(ActivityThread.java:8167)
   at java.lang.reflect.Method.invoke(Method.java)
   at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:496)
   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1100)

代码 NotificationListPresenter

    public class NotificationListPresenter extends BasePresenter<NotificationListView> {

private BaseActivity activity = (BaseActivity) getView();

public NotificationListPresenter(NotificationListView viewInstance) {
    super(viewInstance);
}

public void obtainNotifications(){
    if(activity!= null && activity.getData() != null && activity.getData().getToken() != null) {
  NotificationService.getInstance().getList(activity.getData().getToken().getValor())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(response -> {
                    something...
                },err -> {
                    somethingIfError(err);
                });
    }
}

ListActivity

public class ListActivity extends BaseActivity<ListPresenter>
    implements ListView,NotificationListView{


// onCreate and onResume call this method if necessary
private void obtainNotifications() {
  NotificationListPresenter notificationListPresenter = new NotificationListPresenter(this);
    notificationListPresenter.obtainNotifications();
}

我不知道问题出在哪里了:(

解决方法

你应该用这个替换 if 语句。因为 .getValor() 在空对象引用上，这就是您面临此崩溃问题的原因。

 if(activity!= null && activity.getData() != null && activity.getData().getToken().getValor() != null)