Pascal (Lazarus/Delphi)
Pascal (Lazarus/Delphi)
Get Object MetaData from Google Cloud Storage
See more Google Cloud Storage Examples
Demonstrates how to download a Google Cloud Storage object's metadata.Chilkat Pascal (Lazarus/Delphi) Downloads
program ChilkatDemo;
// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.
{$IFDEF FPC}
{$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}
uses
{$IFDEF UNIX}
cthreads,
{$ENDIF}
SysUtils,
CkDllLoader,
Chilkat.Http,
Chilkat.StringBuilder;
// ---------------------------------------------------------------------------
procedure RunDemo;
var
success: Boolean;
sbToken: TStringBuilder;
http: THttp;
url: string;
sbMetaData: TStringBuilder;
responseCode: Integer;
begin
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..
sbToken := TStringBuilder.Create;
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"
http := THttp.Create;
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');
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..
sbMetaData := TStringBuilder.Create;
success := http.DownloadSb(url,'utf-8',sbMetaData);
if (success = False) then
begin
WriteLn(http.LastErrorText);
Exit;
end;
responseCode := http.LastStatus;
if (responseCode = 401) then
begin
WriteLn('If invalid credentials, then it is likely the access token expired.');
WriteLn('Your app should automatically fetch a new access token and re-try.');
end;
if (responseCode <> 200) then
begin
WriteLn('Error response code = ' + responseCode);
WriteLn('Error:');
WriteLn(sbMetaData.GetAsString());
Exit;
end;
WriteLn(sbMetaData.GetAsString());
WriteLn('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="
// }
//
sbToken.Free;
http.Free;
sbMetaData.Free;
end;
// ---------------------------------------------------------------------------
begin
try
RunDemo;
except
on E: Exception do
WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
end;
WriteLn;
{$IFDEF MSWINDOWS}
WriteLn('Press Enter to exit...');
ReadLn;
{$ENDIF}
end.