我正在尝试使用 BackgroundMode.disableWebViewOptimizations(); 在我的ionic应用程序中，但当我在android studio中启动该应用程序时，我会遇到此错误

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.siloc.users, PID: 6275
    java.lang.NullPointerException: Attempt to invoke interface method 'android.view.View org.apache.cordova.CordovaWebViewEngine.getView()' on a null object reference
        at de.appplant.cordova.plugin.background.BackgroundModeExt$1.lambda$run$0$BackgroundModeExt$1(BackgroundModeExt.java:169)
        at de.appplant.cordova.plugin.background.-$$Lambda$BackgroundModeExt$1$ENae6xHnDD7pQOdOSwld6cT0QNo.run(Unknown Source:2)
        at android.os.Handler.handleCallback(Handler.java:883)
        at android.os.Handler.dispatchMessage(Handler.java:100)
        at android.os.Looper.loop(Looper.java:230)
        at android.app.ActivityThread.main(ActivityThread.java:7880)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:526)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1034)
E/NetdClient: querySockNetidForUid nid:0, uid:10357, command.cmdId:11, id:0

这是backgroundmodeext.java文件中的函数

private void disableWebViewOptimizations() {
        Thread thread = new Thread(){
            public void run() {
                try {
                    Thread.sleep(1000);
                    getApp().runOnUiThread(() -> {
                        View view = webView.getEngine().getView();
                        try {
                            Class.forName("org.crosswalk.engine.XWalkCordovaView")
                                 .getMethod("onShow")
                                 .invoke(view);
                        } catch (Exception e){
                            view.dispatchWindowVisibilityChanged(View.VISIBLE);
                        }
                    });
                } catch (InterruptedException e) {
                    // do nothing
                }
            }
        };
        thread.start();
    }

我有办法解决这个问题吗？