java.nio.file.NoSuchFileException - 从 GCS 下载文件

Question

我正在尝试从 Google 云存储下载文件。我正在使用 Google 的 Github 代码 here on line 1042。我相信我的错误与文件路径有关。路径变量是说明文件下载到的位置和它的新名称，对吗？请注意，我正在使用 JSP 按钮来启动该过程。为了让自己更容易解决问题，我将 String 和 Path 变量替换为 String 而不是 HttpServletRequest。

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    // [START storage_download_file]
    // The name of the bucket to access
    String bucketName = "media";

    // The name of the remote file to download
    String srcFilename = "File.rtf";

    // The path to which the file should be downloaded
    Path destFilePath = Paths.get("/Volumes/Macintosh HD/Users/ab/Desktop/File.rtf");

    // Instantiate a Google Cloud Storage client
    Storage storage = StorageOptions.getDefaultInstance().getService();

    // Get specific file from specified bucket
    Blob blob = storage.get(BlobId.of(bucketName, srcFilename));

    // Download file to specified path
    blob.downloadTo(destFilePath);
    // [END storage_download_file]
}

原因：java.nio.file.NoSuchFileException：/Volumes/Macintosh HD/Users/ab/Desktop/File.rtf

Answer 1

代码在 GitHub in the Google APIs 上找到。我缺少的部分和概念是

OutputStream outStream = response.getOutputStream();

这会将数据发送回客户端的浏览器。

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {   

    /**** Define variables ****/
    Storage storage = StorageOptions.getDefaultInstance().getService();
    String bucketName = "bucketName";
    String objectName = "objectName";

    /**** Setting The Content Attributes For The Response Object ****/
    String mimeType = "application/octet-stream";
    response.setContentType(mimeType);

    /**** Setting The Headers For The Response Object ****/
    String headerKey = "Content-Disposition";
    String headerValue = String.format("attachment; filename=\"%s\"", objectName);
    response.setHeader(headerKey, headerValue);

    /**** Get the Output Stream of the Response Object****/
    OutputStream outStream = response.getOutputStream();

    /**** Call download method ****/
    run(storage, bucketName, objectName, outStream);
}

private void run(Storage storage, String bucketName, String objectName, OutputStream outStream)throws IOException {
    /**** Getting the blob ****/
    BlobId blobId = BlobId.of(bucketName, objectName);
    Blob blob = storage.get(blobId);

    /**** Writing the content that will be sent in the response ****/
    byte[] content = blob.getContent();
    outStream.write(content);
    outStream.close();
}

java.nio.file.NoSuchFileException - 从 GCS 下载文件

java.nio.file.NoSuchFileException - Download files from GCS

java

nosuchfileexception

google-cloud-platform