当您通过firebase上传文件时，ui将自动生成一个访问令牌，但不会为通过java上传的文件生成访问令牌。
您需要创建一个Map来定义一些元数据。

Map<String, String> map = new HashMap<>();
map.put("firebaseStorageDownloadTokens", imageName);

把它传给你的女朋友：

BlobInfo blobInfo = BlobInfo.newBuilder(blobId)
                .setMetadata(map)
                .setContentType(file.getContentType())
                .build();

您的代码应该如下所示：

public FileRequest uploadImage(FileRequest fileRequest, MultipartFile file) throws IOException {
        if(file.isEmpty()){
            throw new NullPointerException("No File Found..");
        }
        byte[] fileByteArray = file.getBytes();
        ClassPathResource resource = new ClassPathResource("firebase.json");
        Storage storage = StorageOptions
                .newBuilder()
                .setCredentials(ServiceAccountCredentials
                        .fromStream(resource.getInputStream()))
                .build()
                .getService();
        String imageName = fileRequest.getUploadContext() + "/" + fileRequest.getFileId();
        Map<String, String> map = new HashMap<>();
        map.put("firebaseStorageDownloadTokens", imageName);
        BlobId blobId = BlobId.of(FileConstant.bucketName, imageName);
        BlobInfo blobInfo = BlobInfo.newBuilder(blobId).setMetadata(map).setContentType(fileRequest.getMimeType()).build();
        storage.create(blobInfo,fileByteArray);
        return fileDAO.uploadFile(fileRequest);
    }