Android API版本低于26如何使用StorageManager获取目录的uuid？

import android.content.Context;
import android.os.storage.StorageManager;
import android.os.storage.StorageVolume;

import java.lang.reflect.Method;

public class StorageUtil {
    public static String getDirectoryUuid(Context context, String directoryPath) {
        try {
            StorageManager storageManager = (StorageManager) context.getSystemService(Context.STORAGE_SERVICE);
            Method getVolumeList = storageManager.getClass().getMethod("getVolumeList");
            StorageVolume[] storageVolumes = (StorageVolume[]) getVolumeList.invoke(storageManager);

            for (StorageVolume volume : storageVolumes) {
                Method getPath = volume.getClass().getMethod("getPath");
                String path = (String) getPath.invoke(volume);
                if (directoryPath.startsWith(path)) {
                    Method getUuid = volume.getClass().getMethod("getUuid");
                    String uuid = (String) getUuid.invoke(volume);
                    return uuid;
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
}

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />