Android 领域空对象引用

当我在没有网络的情况下启动应用程序并调用数据库应用程序崩溃中的数据时，这是我的代码

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

我在这里制造了一场大火

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);}}

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

---

发生异常是因为调用

getAllMovies

方法时，

realm

变量为null

---

记住调用

realm=realm.getDefaultInstance（）

之前。

发生异常是因为调用

getAllMovies

方法时，

realm

变量为null

记住调用

realm=realm.getDefaultInstance（）以前