Copy Object

Updated at：2025-11-03

Simply Copy Object

Basic workflow

Instantiate the BOSClient class.
Execute the BOSClient.copyObject method.
Return a BOSCopyObjectResponse instance. The eTag and last modification timestamp can be accessed via eTag/lastModified, among other methods.

Example code

Swift

1BOSCopyObjectRequest* request = [[BOSCopyObjectRequest alloc] init];
2request.bucket = @"<bucketname>";
3request.key = @"<objectname>";
4request.source = @"<sourceBucket>/<sourceObject";
5__block BOSCopyObjectResponse* response = nil;
6BCETask* task = [client copyObject:request];
7task.then(^(BCEOutput* output) {
8    if (output.response) {
9        response = (BOSCopyObjectResponse*)output.response;
10        NSLog(@"copy obj success!");
11    }
12    if (output.error) {
13        NSLog(@"copy obj failure");
14    }
15});
16[task waitUtilFinished];

Complete example

Swift

1#import <BaiduBCEBasic/BaiduBCEBasic.h>
2#import <BaiduBCEBOS/BaiduBCEBOS.h>
3void example(void) {
4 // Initialize
5    BCECredentials* credentials = [[BCECredentials alloc] init];
6    credentials.accessKey = @"<access key>";
7    credentials.secretKey = @"<secret key>";
8    BOSClientConfiguration* configuration = [[BOSClientConfiguration alloc] init];
9    configuration.credentials = credentials;
10    BOSClient* client = [[BOSClient alloc] initWithConfiguration:configuration];
11    BOSCopyObjectRequest* request = [[BOSCopyObjectRequest alloc] init];
12    request.bucket = @"<bucketname>";
13    request.key = @"<objectname>";
14    request.source = @"<sourceBucket>/<sourceObject";
15    __block BOSCopyObjectResponse* response = nil;
16    BCETask* task = [client copyObject:request];
17    task.then(^(BCEOutput* output) {
18      if (output.response) {
19          response = (BOSCopyObjectResponse*)output.response;
20          NSLog(@"copy obj success!");
21      }
22      if (output.error) {
23          NSLog(@"copy obj failure");
24      }
25    });
26    [task waitUtilFinished];
27}

Note: The copyObject method returns a BOSCopyObjectResponse object containing the new object's ETag and modification time.

Copy object with specified conditions

Copy an object with conditions specified. This functionality is typically applied in scenarios like:

Copy an object while resetting its metadata.
Resetting the metadata of an existing object by setting both the source and the target to the same object.
Copy when the eTag of the source object is the same as the specified eTag;
Copy when the eTag of the source object is the different from the specified eTag;
Copy when the source object has not been modified after the specified time;
Copy when the source object has been modified after the specified time;

Details as follows:

Basic workflow

Create an instance of the BOSCopyObjectRequest class, and pass in the parameters <source>,<ifMatchEtag>, <ifNotMatchEtag>,<ifModifiedSince>,<ifUnmodifiedSince>, <metadataDirective>.
Return a BOSCopyObjectResponse instance. The eTag and last modification timestamp can be accessed via eTag/lastModified, among other methods.

Example code

Swift

1BOSCopyObjectRequest* request = [[BOSCopyObjectRequest alloc] init];
2request.bucket = @"<bucketname>";
3request.key = @"<objectname>";
4request.source = @"<sourceBucket>/<sourceObject";
5request.metadataDirective = @"replace";
6request.ifModifiedSince = @"Wed, 01 Mar 2006 12:00:00 GMT";
7__block BOSCopyObjectResponse* response = nil;
8BCETask* task = [client copyObject:request];
9task.then(^(BCEOutput* output) {
10  if (output.response) {
11      response = (BOSCopyObjectResponse*)output.response;
12      NSLog(@"copy obj success!");
13  }
14  if (output.error) {
15      NSLog(@"copy obj failure");
16  }
17});
18[task waitUtilFinished];

Note:BOSCopyObjectRequest allows users to modify the ObjectMeta of the target object and also provides the setting of the MatchingETagConstraints parameter.

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