我在casecadeclassifier.java类中收到空指针异常

在这里:

Mat objects_mat = objects;

detectMultiScale_4(nativeObj, image.nativeObj, objects_mat.nativeObj, scaleFactor);

这是我的日志:

02-11 20:53:15.209 10968-10968/? E/SystemUpdate-ReflectUtils: getClass android.provider.MiuiSettings$Privacy java.lang.ClassNotFoundException: android.provider.MiuiSettings$Privacy

02-11 20:53:15.596 11016-11016/? E/MiPicks-ReflectUtils: getField null.ACTION_PRIVACY_AUTHORIZATION_DIALOG java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String java.lang.Class.toString()' on a null object reference

02-11 20:53:15.597 11016-11016/? E/MiPicks-ReflectUtils: getFieldValue null.PRIVACY_PREFIX java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.reflect.Field java.lang.Class.getDeclaredField(java.lang.String)' on a null object reference

:18.013 11076-11263/? E/org.opencv.objdetect: objdetect::detectMultiScale_14() caught cv::Exception: OpenCV(4.0.1) /build/master_pack-android/opencv/modules/objdetect/src/cascadedetect.cpp:1658: error: (-215:Assertion failed) !empty() in function 'detectMultiScale'

02-11 20:53:18.014 11076-11263/? E/AndroidRuntime: FATAL EXCEPTION: Thread-4

Process: com.therobustprogrammer.opencvtestapp, PID: 11076

CvException [org.opencv.core.CvException: cv::Exception: OpenCV(4.0.1) /build/master_pack-android/opencv/modules/objdetect/src/cascadedetect.cpp:1658: error: (-215:Assertion failed) !empty() in function 'detectMultiScale'

]

at org.opencv.objdetect.CascadeClassifier.detectMultiScale_4(Native Method)

at org.opencv.objdetect.CascadeClassifier.detectMultiScale(CascadeClassifier.java:192)

at com.therobustprogrammer.opencvtestapp.MainActivity.onCameraFrame(MainActivity.java:205)

at org.opencv.android.CameraBridgeViewBase.deliverAndDrawFrame(CameraBridgeViewBase.java:392)

at org.opencv.android.JavaCameraView$CameraWorker.run(JavaCameraView.java:373)

at java.lang.Thread.run(Thread.java:760)

我在这里添加分类器

Imgproc.cvtColor(inputFrame.rgba(), matGray, Imgproc.COLOR_RGB2GRAY);

MatOfRect faceDetections = new MatOfRect();

cascadeFaceClassifier.detectMultiScale(matGray, faceDetections, 5);

这里是我的初始化

File faceClassifierDir = getDir("sampledata", Context.MODE_PRIVATE);

File mCasecadeFile = new File(faceClassifierDir, "haarcascade_eye.xml");

System.out.println("Absolute Path : " + mCasecadeFile.getAbsolutePath());

cascadeFaceClassifier = new CascadeClassifier(mCasecadeFile.getAbsolutePath());

cascadeFaceClassifier.load(mCasecadeFile.getAbsolutePath());

应用程序在主活动中崩溃。我是新来的,请帮忙。