Question

当我使用网络启动我的应用程序并在我的数据库应用程序崩溃中调用我的数据时，这是我的代码

 public void getAllMovies() {
    findData = realm.where(MovieDb.class).findAll();
    movieArrayList = new ArrayList(findData);
    movieMethod();
}

我在这里发生了大火

public class myApplication extends Application {

@Override
public void onCreate() {
    super.onCreate();
    RealmConfiguration configuration = new RealmConfiguration
            .Builder(this).name("Movie_database.realm").build();
    Realm.setDefaultConfiguration(configuration);}}

和moviedb是我的领域对象
我的应用程序崩溃了

    findData = realm.where(MovieDb.class).findAll();

这是我的错误

E/AndroidRuntime: FATAL EXCEPTION: main
              Process: com.massive.movieapp, PID: 4222
              java.lang.RuntimeException: Unable to start activity ComponentInfo{com.massive.movieapp/com.massive.movieapp.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'io.realm.RealmQuery io.realm.Realm.where(java.lang.Class)' on a null object reference
                  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416)
                  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
                  at android.app.ActivityThread.-wrap11(ActivityThread.java)
                  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
                  at android.os.Handler.dispatchMessage(Handler.java:102)
                  at android.os.Looper.loop(Looper.java:148)
                  at android.app.ActivityThread.main(ActivityThread.java:5417)
                  at java.lang.reflect.Method.invoke(Native Method)
                  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
               Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'io.realm.RealmQuery io.realm.Realm.where(java.lang.Class)' on a null object reference
                  at com.massive.movieapp.FragmentForActivity.getAllMovies(FragmentForActivity.java:143)
                  at com.massive.movieapp.FragmentForActivity.CallNetwork(FragmentForActivity.java:62)
                  at com.massive.movieapp.FragmentForActivity.onCreate(FragmentForActivity.java:55)
                  at android.app.Fragment.performCreate(Fragment.java:2198)
                  at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:942)
                  at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1148)
                  at android.app.BackStackRecord.run(BackStackRecord.java:793)
                  at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1535)
                  at android.app.FragmentController.execPendingActions(FragmentController.java:325)
                  at android.app.Activity.performStart(Activity.java:6252)
                  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2379)
                  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476) 
                  at android.app.ActivityThread.-wrap11(ActivityThread.java) 
                  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344) 
                  at android.os.Handler.dispatchMessage(Handler.java:102) 
                  at android.os.Looper.loop(Looper.java:148) 
                  at android.app.ActivityThread.main(ActivityThread.java:5417) 
                  at java.lang.reflect.Method.invoke(Native Method

Answer 1

发生异常是因为当您调用realm方法时，getAllMovies变量为空。

请记得先前致电realm = Realm.getDefaultInstance();。

领域空对象引用

1 个答案: