Как скопировать файл перед удалением с помощью FileObserver andorid программно

Question

Как скопировать файл перед удалением с помощью FileObserver

Вот код, который я пытался скопировать, перед удалением файлов с помощью FileObserver. Пожалуйста, помогите мне решить эту проблему. Я хочу скопировать файл перед удалением в каталог приложения программно с помощью Android, например Dumpster.

public class RecoverFileObserver extends FileObserver {
    private  String RECOVERY_DIR = "/storage/emulated/0/Android/data/com.demo.recovery/.trash";
    private String TAG = RecoverFileObserver.class.getSimpleName();
    private HashMap<String, RecoverInfo> recoverInfoHashMap = new HashMap<>();
    String originMd5 = "xyz";
    FileInputStream fileInputStream;
    String path;
    String newPath;
    private int length = 0;
    String extension;
    private HashMap<File, RecoverFileObserver> myFileObserverHashMap = new HashMap<>();

    public RecoverFileObserver(String path) {
        super(path, FileObserver.ALL_EVENTS);
        this.path = path;
        if (path.lastIndexOf(".") != -1) {
            extension = path.substring(path.lastIndexOf("."));
            this.newPath = RECOVERY_DIR + "/" + Md5Util.getMD5Str(path) + extension;
        } else {
            this.newPath = RECOVERY_DIR + "/" + Md5Util.getMD5Str(path);
        }

        try {
            fileInputStream = new FileInputStream(path);
            length = fileInputStream.available();
        } catch (IOException e) {
            e.printStackTrace();
        }
        RecoverInfo info = new RecoverInfo();
        info.originMd5 = originMd5;
        info.recoveryPath = newPath;
        recoverInfoHashMap.put(path, info);
    }

    @Override
    public void onEvent(int event, String path) {
        if (event == FileObserver.ACCESS) return;
        Log.e(TAG, this.path + " | " + path + " : " + event);
        switch (event) {
            case FileObserver.ACCESS:
                Log.e("ACCESS", "" + this.path + " | " + path + " : " + event);
                break;

            case FileObserver.ALL_EVENTS:
                Log.e("ALL_EVENTS", " " + this.path + " | " + path + " : " + event);
                break;

            case FileObserver.CLOSE_NOWRITE:
                Log.e("CLOSE_NOWRITE", " " + this.path + " | " + path + " : " + event);
                break;

            case FileObserver.CLOSE_WRITE:
                Log.e("CLOSE_WRITE", "" + this.path + " | " + path + " : " + event);
                break;

            case FileObserver.CREATE:
                Log.e("CREATE", "" + this.path + " | " + path + " : " + event);
                break;

            case FileObserver.MODIFY:
                Log.e("MODIFY", " " + this.path + " | " + path + " : " + event);
                break;

            case FileObserver.MOVED_FROM:
                Log.e("xyzabc", " " + this.path + " | " + path + " : " + event);
                break;

            case FileObserver.MOVED_TO:
                Log.e("MOVED_TO", " " + this.path + " | " + path + " : " + event);
                break;

            case FileObserver.MOVE_SELF:
                Log.e("MOVE_SELF", " " + this.path + " | " + path + " : " + event);
                break;

            case FileObserver.OPEN:
                Log.e("OPEN", "i " + this.path + " | " + path + " : " + event);
                break;

            case FileObserver.ATTRIB:
                Log.e("ATTRIB", " " + this.path + " | " + path + " : " + event);
                copyFile(fileInputStream, this.path, this.newPath, length, originMd5);
                break;

            case FileObserver.DELETE:
                Log.e("DELETE", "  " + this.path + " | " + path + " : " + event);
                copyFile(fileInputStream, this.path, this.newPath, length, originMd5);
                break;

            case FileObserver.DELETE_SELF:
                Log.e("DELETE_SELF", "");
                copyFile(fileInputStream, this.path, this.newPath, length, originMd5);
                break;

            case 32768:
                Log.e("32768", "");
                stopWatching();
                File file = new File(this.path);
                if (file.exists()) {
                    RecoverFileObserver fileObserver = new RecoverFileObserver(this.path);
                    fileObserver.startWatching();
                    myFileObserverHashMap.put(file, fileObserver);
                } else {
                    myFileObserverHashMap.remove(file);
                }
                break;
            default:
                break;
        }
    }

    private void copyFile(FileInputStream is, String path, String newPath, int length, String originMd5) {
        try {
            createOrExistsDir(new File(RECOVERY_DIR));
            OutputStream os = new FileOutputStream(newPath);
            byte[] buffer = new byte[1024];
            int bytesRead;
            while ((bytesRead = is.read(buffer)) != -1) {
                os.write(buffer, 0, bytesRead);
            }
            is.close();
            os.flush();
            os.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static boolean createOrExistsDir(File file) {
        return file != null && (file.exists() ? file.isDirectory() : file.mkdirs());
    }

    @Override
    protected void finalize() {
        Log.e("FINALIZE:", " finalize");
        super.finalize();

    }
}

Этот код для обнаружения ACCESS, OPEN, CLOSE_NOWRITE, но DELETE Event не вызывает каждый раз, какрешить эту проблему в этом коде. Спасибо!