App Engine & Cloud Storage 如何以编程方式使用 public link 权限保存文件

Question

我写了一个创建缩略图的函数，但是缩略图没有public link，即使原始文件有权限User-allUsers-Reader 和 public link https://storage.googleapis.com/{buckets}/{filename} 供所有用户访问文件。

如何将此权限添加到我的缩略图。

public static void thumbnailImage(String filename, int width, int height) throws IOException{
    GcsService gcsService = GcsServiceFactory.createGcsService(new RetryParams.Builder()
              .initialRetryDelayMillis(10)
              .retryMaxAttempts(10)
              .totalRetryPeriodMillis(15000)
              .build());
    AppIdentityService appIdentity = AppIdentityServiceFactory.getAppIdentityService();
    ImagesService imagesService = ImagesServiceFactory.getImagesService();
    // Make an image from a Cloud Storage object, and transform it.
    BlobstoreService blobstoreService = BlobstoreServiceFactory.getBlobstoreService();
    BlobKey blobKey = blobstoreService.createGsBlobKey("/gs/" + appIdentity.getDefaultGcsBucketName() +"/"+ filename);

    Image thumb = null;
    try{
        Image blobImage = ImagesServiceFactory.makeImageFromBlob(blobKey);          
        Transform resize = ImagesServiceFactory.makeResize(width, height);
        thumb = imagesService.applyTransform(resize, blobImage);

    }catch(Exception e){
        e.printStackTrace();
    }
    String extension = Files.getFileExtension(filename);
    filename = stripExtension(filename);
    filename = String.format("%1$s_%2$s.%3$s", filename, thumbnail, extension);

    if(thumb!=null)
    // Write the transformed image back to a Cloud Storage object.
    gcsService.createOrReplace(
        new GcsFilename(appIdentity.getDefaultGcsBucketName(), filename),
        new GcsFileOptions.Builder().mimeType("image/jpeg").build(),
        ByteBuffer.wrap(thumb.getImageData()));
}

Answer 1

您可以使用 GcsFileOption 参数 "acl" 使其对其他人可见。因此，将最后的那个位更改为：

new GcsFileOptions.Builder().mimeType("image/jpeg").acl("public-read").build(),

public link 与 storage.googleapis.com/bucket/object 模式相同，只是对象是缩略图的名称。

App Engine & Cloud Storage 如何以编程方式使用 public link 权限保存文件

App Engine & Cloud Storage How to save file with the permission with a public link programmatically

java

google-app-engine

google-cloud-storage