Get Object MetaData from Google Cloud Storage

Demonstrates how to download a Google Cloud Storage object's metadata.
Chilkat C# Downloads

bool success = false;

//  This example requires the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

//  This example uses a previously obtained access token having permission for the 
//  scope "https://www.googleapis.com/auth/cloud-platform"

//  In this example, Get Google Cloud Storage OAuth2 Access Token, 
//  the service account access token was saved to a text file.  This example fetches the access token from the file..
Chilkat.StringBuilder sbToken = new Chilkat.StringBuilder();
sbToken.LoadFile("qa_data/tokens/googleCloudStorageAccessToken.txt","utf-8");

//  Send a GET equivalent to this curl command.

//  curl -X GET \
//      -H "Authorization: Bearer [OAUTH2_TOKEN]" \
//      -o "[SAVE_TO_LOCATION]" \
//      "https://www.googleapis.com/storage/v1/b/[BUCKET_NAME]/o/[OBJECT_NAME]?projection=full"

Chilkat.Http http = new Chilkat.Http();

http.AuthToken = sbToken.GetAsString();

//  Construct a URL to download the metadata for the object named "starfish.jpg" located in the "chilkat-ocean" bucket.
http.SetUrlVar("bucket_name","chilkat-ocean");
http.SetUrlVar("object_name","starfish.jpg");
string url = "https://www.googleapis.com/storage/v1/b/{$bucket_name}/o/{$object_name}?projection=full";

//  If there is an error response, then we didn't actually download the metadata,
//  but instead we downloaded an error response..
Chilkat.StringBuilder sbMetaData = new Chilkat.StringBuilder();
success = http.DownloadSb(url,"utf-8",sbMetaData);
if (success == false) {
    Debug.WriteLine(http.LastErrorText);
    return;
}

int responseCode = http.LastStatus;
if (responseCode == 401) {
    Debug.WriteLine("If invalid credentials, then it is likely the access token expired.");
    Debug.WriteLine("Your app should automatically fetch a new access token and re-try.");
}

if (responseCode != 200) {
    Debug.WriteLine("Error response code = " + Convert.ToString(responseCode));
    Debug.WriteLine("Error:");
    Debug.WriteLine(sbMetaData.GetAsString());
    return;
}

Debug.WriteLine(sbMetaData.GetAsString());
Debug.WriteLine("Success.");

//  Sample output:

//  {
//   "kind": "storage#object",
//   "id": "chilkat-ocean/starfish.jpg/1502670320090292",
//   "selfLink": "https://www.googleapis.com/storage/v1/b/chilkat-ocean/o/starfish.jpg",
//   "name": "starfish.jpg",
//   "bucket": "chilkat-ocean",
//   "generation": "1502670320090292",
//   "metageneration": "1",
//   "contentType": "image/jpeg",
//   "timeCreated": "2017-08-14T00:25:20.040Z",
//   "updated": "2017-08-14T00:25:20.040Z",
//   "storageClass": "MULTI_REGIONAL",
//   "timeStorageClassUpdated": "2017-08-14T00:25:20.040Z",
//   "size": "6229",
//   "md5Hash": "LpxZ2/JmI2fcl9/dqF2gSA==",
//   "mediaLink": "https://www.googleapis.com/download/storage/v1/b/chilkat-ocean/o/starfish.jpg?generation=1502670320090292&alt=media",
//   "acl": [
//    {
//     "kind": "storage#objectAccessControl",
//     "id": "chilkat-ocean/starfish.jpg/1502670320090292/project-owners-933037264567",
//     "selfLink": "https://www.googleapis.com/storage/v1/b/chilkat-ocean/o/starfish.jpg/acl/project-owners-933037264567",
//     "bucket": "chilkat-ocean",
//     "object": "starfish.jpg",
//     "generation": "1502670320090292",
//     "entity": "project-owners-933037264567",
//     "role": "OWNER",
//     "projectTeam": {
//      "projectNumber": "933037264567",
//      "team": "owners"
//     },
//     "etag": "CLT5kpW71dUCEAE="
//    },
//    {
//     "kind": "storage#objectAccessControl",
//     "id": "chilkat-ocean/starfish.jpg/1502670320090292/project-editors-933037264567",
//     "selfLink": "https://www.googleapis.com/storage/v1/b/chilkat-ocean/o/starfish.jpg/acl/project-editors-933037264567",
//     "bucket": "chilkat-ocean",
//     "object": "starfish.jpg",
//     "generation": "1502670320090292",
//     "entity": "project-editors-933037264567",
//     "role": "OWNER",
//     "projectTeam": {
//      "projectNumber": "933037264567",
//      "team": "editors"
//     },
//     "etag": "CLT5kpW71dUCEAE="
//    },
//    {
//     "kind": "storage#objectAccessControl",
//     "id": "chilkat-ocean/starfish.jpg/1502670320090292/project-viewers-933037264567",
//     "selfLink": "https://www.googleapis.com/storage/v1/b/chilkat-ocean/o/starfish.jpg/acl/project-viewers-933037264567",
//     "bucket": "chilkat-ocean",
//     "object": "starfish.jpg",
//     "generation": "1502670320090292",
//     "entity": "project-viewers-933037264567",
//     "role": "READER",
//     "projectTeam": {
//      "projectNumber": "933037264567",
//      "team": "viewers"
//     },
//     "etag": "CLT5kpW71dUCEAE="
//    },
//    {
//     "kind": "storage#objectAccessControl",
//     "id": "chilkat-ocean/starfish.jpg/1502670320090292/user-starfish@chilkat-176611.iam.gserviceaccount.com",
//     "selfLink": "https://www.googleapis.com/storage/v1/b/chilkat-ocean/o/starfish.jpg/acl/user-starfish@chilkat-176611.iam.gserviceaccount.com",
//     "bucket": "chilkat-ocean",
//     "object": "starfish.jpg",
//     "generation": "1502670320090292",
//     "entity": "user-starfish@chilkat-176611.iam.gserviceaccount.com",
//     "role": "OWNER",
//     "email": "starfish@chilkat-176611.iam.gserviceaccount.com",
//     "etag": "CLT5kpW71dUCEAE="
//    }
//   ],
//   "owner": {
//    "entity": "user-starfish@chilkat-176611.iam.gserviceaccount.com"
//   },
//   "crc32c": "9RjgwQ==",
//   "etag": "CLT5kpW71dUCEAE="
//  }
//