java.io.FileNotFoundException:打开失败:EACCES(权限被拒绝)

     File path = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "picture");
    if (! path.exists()) {
        path.mkdirs();
        if (!path.exists()) {
            return null;
        }
    }
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HH_mm_ss", Locale.CHINA).format(new Date());
    File imagePath = new File(path.getPath() + "_" + "IMG_" + timeStamp + ".jpg");
    BufferedOutputStream fos;
    try {
        fos =new BufferedOutputStream(new FileOutputStream(imagePath));
        bitmap.compress(Bitmap.CompressFormat.PNG, 100, fos);
        fos.flush();
        fos.close();
        return imagePath;
    } catch (FileNotFoundException e) {
        Log.e("GREC", e.getMessage(), e);
        return null;
    } catch (IOException e) {
        Log.e("GREC", e.getMessage(), e);
        return null;
    }

fos = new BufferedOutputStream(new FileOutputStream(imagePath)); [我调试并发现此行导致了错误]

并且清单中的权限设置正确

fos =new BufferedOutputStream(new FileOutputStream(imagePath));[I debug and found this line cause the error]

And in manifest the permission set is right