android 9.0 获取U盘路径

/**
 * android 9.0获取外置sdcard和U盘路径，并区分
 * * @param mContext
 * * @param keyword  SD = "内部存储"; EXT = "SD卡"; USB = "U盘"
 * * @return
 * */
public static String getStoragePath(Context mContext,String keyword){
        String targetpath = "";
        StorageManager mStorageManager = (StorageManager) mContext.getSystemService(Context.STORAGE_SERVICE);
        Class storageVolumeClazz = null;
        try {
            storageVolumeClazz = Class.forName("android.os.storage.StorageVolume");
            Method getVolumeList = mStorageManager.getClass().getMethod("getVolumeList");
            Method getPath = storageVolumeClazz.getMethod("getPath");

            Object result = getVolumeList.invoke(mStorageManager);
            final int length = Array.getLength(result);
            Method getUserLabel = storageVolumeClazz.getMethod("getUserLabel");

            for (int i = 0; i < length; i++){
                Object storageVolumeElement = Array.get(result, i);
                String userLabel = (String) getUserLabel.invoke(storageVolumeElement);
                String path = (String) getPath.invoke(storageVolumeElement);
                if(userLabel.contains(keyword)){
                    targetpath = path;
                    targetpath = targetpath +"/xxx";
                    File dirFile = new File(targetpath);
                    if (!dirFile.exists()) {              //如果不存在，那就建立这个文件夹
                        dirFile.mkdirs();
                    }
                }
            }
        } catch (ClassNotFoundException e){
                    e.printStackTrace();
        } catch (InvocationTargetException e) {
                        e.printStackTrace();
        } catch (NoSuchMethodException e) {
                e.printStackTrace();
        } catch (IllegalAccessException e) {
                e.printStackTrace();
        }
        return targetpath ;
    }