Autodesk Forge：下载清单附件

Question

当我检索一个清单实例时，我得到了以下与附件相关的部分。

    {
  "type": "instance_item_attachments",
  "id": "5a0a2acf-b02a-4b88-86cc-962c3831bdee",
  "attributes": {
    "name": "6856ad10-6ab0-11e9-9150-9fda3da0626e.png",
    "attachmentType": "OSS",
    "mimeType": "image/png",
    "uploadStatus": "COMPLETED",
    "urns": [
      {
        "urn": "urn:adsk.wipprod:fs.file:vf.gy4mB910SneymU86Gc4O0A?version=1",
        "type": "WIP"
      },
      {
        "urn": "urn:adsk.objects:os.object:wip.dm.prod/ede3de59-1b68-485c-82fe-f1f2af3442fe.png",
        "type": "OSS"
      },
      {
        "urn": "urn:adsk.checklists.cs.attachment:58b8afcf-d7cd-49ad-aa10-78c50610761b/5a0a2acf-b02a-4b88-86cc-962c3831bdee",
        "type": "CHECKLIST"
      }
    ],
    "createdAt": "2019-04-29T18:55:51.334Z",
    "updatedAt": "2019-04-29T18:55:54.137Z",
    "createdBy": "TAKCJQU6HGXW",
    "modifiedBy": "TAKCJQU6HGXW",
    "permittedActions": [
      "canArchive",
      "canEdit"
    ],
    "permittedAttributes": [
      "mimeType",
      "uploadStatus"
    ]
  },
  "links": {
    "self": "/containers/58b8afcf-d7cd-49ad-aa10-78c50610761b/instance_item_attachments/5a0a2acf-b02a-4b88-86cc-962c3831bdee"
  },
  "relationships": {
    "container": {
      "meta": {
        "relation": "primary",
        "readOnly": false
      },
      "links": {
        "self": "/containers/58b8afcf-d7cd-49ad-aa10-78c50610761b/instance_item_attachments/5a0a2acf-b02a-4b88-86cc-962c3831bdee/relationships/container",
        "related": "/containers/58b8afcf-d7cd-49ad-aa10-78c50610761b/instance_item_attachments/5a0a2acf-b02a-4b88-86cc-962c3831bdee/container"
      },
      "data": {
        "type": "containers",
        "id": "58b8afcf-d7cd-49ad-aa10-78c50610761b"
      }
    },
    "item": {
      "meta": {
        "relation": "primary",
        "readOnly": false
      },
      "links": {
        "self": "/containers/58b8afcf-d7cd-49ad-aa10-78c50610761b/instance_item_attachments/5a0a2acf-b02a-4b88-86cc-962c3831bdee/relationships/item",
        "related": "/containers/58b8afcf-d7cd-49ad-aa10-78c50610761b/instance_item_attachments/5a0a2acf-b02a-4b88-86cc-962c3831bdee/item"
      },
      "data": null
    }
  }
}

现在，我要下载这个附件，提供的URN是：wip.dm.prod/ede3de59-1b68-485c-82fe-f1f2af3442fe.png

如果我尝试使用以下链接访问它，它会显示未找到

developer.api.autodesk.com/oss/v2/buckets/wip.dm.prod/b30e3ffe-333b-446c-b834-e2f2141096b4.png

但是，如果我稍微更改一下 URL（通过添加对象），它就可以正常工作。

developer.api.autodesk.com/oss/v2/buckets/wip.dm.prod/objects/b30e3ffe-333b-446c-b834-e2f2141096b4.png

我在这里做错了吗？或者这是提供的骨灰盒中的错误？

Answer 1

添加到Adam Nagy reply，您需要破坏 URN。从你原来的问题：

urn:adsk.objects:os.object:wip.dm.prod/ede3de59-1b68-485c-82fe-f1f2af3442fe.png

在 .NET 中，您可以尝试（使用 System.Linq）：

string bucketKey = urn.Split("/").First().Split(":").Last();
string objectName = urn.Split("/").Last();

然后重建为：

string attachemtnUrl = string.Format("{0}/oss/v2/buckets/{1}/objects/{2}", BASE_URL, bucketKey, objectName);

您还需要带有有效访问令牌的 Authorization 标头。

Answer 2

OSS（对象存储服务）中对象的id / urn包含bucket name和object name 在“urn:adsk.objects:os.object:”部分之后。

有下载文件的教程https://forge.autodesk.com/en/docs/data/v2/tutorials/download-file/

表示关于item的回复包含storage下下载链接的id和实际的URL 部分：

"storage": {
  "data": {
    "type": "objects",
    "id": "urn:adsk.objects:os.object:wip.dm.prod/977d69b1-43e7-40fa-8ece-6ec4602892f3.rvt"
  },
  "meta": {
    "link": {
      "href": "https://developer.api.autodesk.com/oss/v2/buckets/wip.dm.prod/objects/977d69b1-43e7-40fa-8ece-6ec4602892f3.rvt"
    }
  }
}

您可以在此处看到 id 和可用于下载文件的 URL 之间的连接