Setting Object Properties

You can set properties for an object when uploading it. Object properties include the MD5 value (for verification), storage class, and customized metadata. You can set properties for an object that is being uploaded in streaming, file-based, or multipart mode or when copying the object.

The following table describes object properties.

static OBSClient *client;
NSString *endPoint = @"your-endpoint";
// Hard-coded or plaintext AK/SK are risky. For security purposes, encrypt your AK/SK and store them in the configuration file or environment variables. In this example, the AK/SK are stored in environment variables for identity authentication. Before running this example, configure environment variables AccessKeyID and SecretAccessKey.
// Obtain an AK/SK pair on the management console. For details, see https://support.huaweicloud.com/intl/en-us/usermanual-ca/ca_01_0003.html.
char* ak_env = getenv("AccessKeyID");
char* sk_env = getenv("SecretAccessKey");
NSString *AK = [NSString stringWithUTF8String:ak_env];
NSString *SK = [NSString stringWithUTF8String:sk_env];

// Initialize identity authentication.
OBSStaticCredentialProvider *credentialProvider = [[OBSStaticCredentialProvider alloc] initWithAccessKey:AK secretKey:SK];
    
//Initialize service configuration.
OBSServiceConfiguration *conf = [[OBSServiceConfiguration alloc] initWithURLString:endPoint credentialProvider:credentialProvider];
    
// Initialize an instance of OBSClient.
client = [[OBSClient alloc] initWithConfiguration:conf];
    
NSString *filePath = [[NSBundle mainBundle]pathForResource:@"fileName" ofType:@"Type"];
//Upload a file.
OBSPutObjectWithFileRequest *request = [[OBSPutObjectWithFileRequest alloc]initWithBucketName:@"bucketname" objectKey:@"objectname" uploadFilePath:filePath];
    
// Set the MD5 value for an object.
request.contentMD5 = @"your md5 which should be encoded by base64"
    
[client putObject:request completionHandler:^(OBSPutObjectResponse *response, NSError *error){
    NSLog(@"%@",response.etag);
}];

• The MD5 value of an object must be a base64-encoded digest.
• The OBS server will compare this MD5 value with the MD5 value obtained by object data calculation. If the two values are not the same, the upload fails with HTTP status code 400 returned.
• If the MD5 value is not specified, the OBS server will skip MD5 value verification.

static OBSClient *client;
NSString *endPoint = @"your-endpoint";
// Hard-coded or plaintext AK/SK are risky. For security purposes, encrypt your AK/SK and store them in the configuration file or environment variables. In this example, the AK/SK are stored in environment variables for identity authentication. Before running this example, configure environment variables AccessKeyID and SecretAccessKey.
// Obtain an AK/SK pair on the management console. For details, see https://support.huaweicloud.com/intl/en-us/usermanual-ca/ca_01_0003.html.
char* ak_env = getenv("AccessKeyID");
char* sk_env = getenv("SecretAccessKey");
NSString *AK = [NSString stringWithUTF8String:ak_env];
NSString *SK = [NSString stringWithUTF8String:sk_env];

// Initialize identity authentication.
OBSStaticCredentialProvider *credentialProvider = [[OBSStaticCredentialProvider alloc] initWithAccessKey:AK secretKey:SK];
    
//Initialize service configuration.
OBSServiceConfiguration *conf = [[OBSServiceConfiguration alloc] initWithURLString:endPoint credentialProvider:credentialProvider];
    
// Initialize an instance of OBSClient.
client = [[OBSClient alloc] initWithConfiguration:conf];
NSString *filePath = [[NSBundle mainBundle]pathForResource:@"fileName" ofType:@"Type"];
//Upload a file.
OBSPutObjectWithFileRequest *request = [[OBSPutObjectWithFileRequest alloc]initWithBucketName:@"bucketname" objectKey:@"objectname" uploadFilePath:filePath];
    
// Set the storage class for an object.
request.storageClass = OBSStorageClassStandard;
    
[client putObject:request completionHandler:^(OBSPutObjectResponse *response, NSError *error){
    NSLog(@"%@",response.etag);
}];

• The storage class of the objects in a bucket is the same as that of the bucket.
• OBS provides objects with three storage classes which are consistent with those provided for buckets.
• Before downloading an Archive object, you must restore it. For details, see Downloading an Archive Object.

static OBSClient *client;
NSString *endPoint = @"your-endpoint";
// Hard-coded or plaintext AK/SK are risky. For security purposes, encrypt your AK/SK and store them in the configuration file or environment variables. In this example, the AK/SK are stored in environment variables for identity authentication. Before running this example, configure environment variables AccessKeyID and SecretAccessKey.
// Obtain an AK/SK pair on the management console. For details, see https://support.huaweicloud.com/intl/en-us/usermanual-ca/ca_01_0003.html.
char* ak_env = getenv("AccessKeyID");
char* sk_env = getenv("SecretAccessKey");
NSString *AK = [NSString stringWithUTF8String:ak_env];
NSString *SK = [NSString stringWithUTF8String:sk_env];

// Initialize identity authentication.
OBSStaticCredentialProvider *credentialProvider = [[OBSStaticCredentialProvider alloc] initWithAccessKey:AK secretKey:SK];
    
//Initialize service configuration.
OBSServiceConfiguration *conf = [[OBSServiceConfiguration alloc] initWithURLString:endPoint credentialProvider:credentialProvider];
    
// Initialize an instance of OBSClient.
client = [[OBSClient alloc] initWithConfiguration:conf];
    
// Upload a character string in streaming mode.
OBSPutObjectWithDataRequest *request = [[OBSPutObjectWithDataRequest alloc]initWithBucketName:@"bucketname" objectKey:@"objectname" uploadData:[@"" dataUsingEncoding:NSUTF8StringEncoding]];

// Set the bucket metadata.
request.metaDataDict = @{@"meta1":@"value1",@"meta2":@"value2"};
    
[client putObject:request completionHandler:^(OBSPutObjectResponse *response, NSError *error){
    NSLog(@"%@",response);
}];

• In the preceding code, two pieces of metadata named meta1 and meta2 are customized and their respective values are set to value1 and value2.
• An object can have multiple pieces of metadata whose total size cannot exceed 8 KB.
• The customized object metadata can be obtained by using OBSGetObjectMetaDataRequest. For details, see Obtaining Object Properties.
• When you use getObject to download an object, its customized metadata will also be downloaded.

static OBSClient *client;
NSString *endPoint = @"your-endpoint";
// Hard-coded or plaintext AK/SK are risky. For security purposes, encrypt your AK/SK and store them in the configuration file or environment variables. In this example, the AK/SK are stored in environment variables for identity authentication. Before running this example, configure environment variables AccessKeyID and SecretAccessKey.
// Obtain an AK/SK pair on the management console. For details, see https://support.huaweicloud.com/intl/en-us/usermanual-ca/ca_01_0003.html.
char* ak_env = getenv("AccessKeyID");
char* sk_env = getenv("SecretAccessKey");
NSString *AK = [NSString stringWithUTF8String:ak_env];
NSString *SK = [NSString stringWithUTF8String:sk_env];

// Initialize identity authentication.
OBSStaticCredentialProvider *credentialProvider = [[OBSStaticCredentialProvider alloc] initWithAccessKey:AK secretKey:SK];
    
//Initialize service configuration.
OBSServiceConfiguration *conf = [[OBSServiceConfiguration alloc] initWithURLString:endPoint credentialProvider:credentialProvider];
    
// Initialize an instance of OBSClient.
client = [[OBSClient alloc] initWithConfiguration:conf];
NSString *filePath = [[NSBundle mainBundle]pathForResource:@"fileName" ofType:@"mp4"];
//Upload a file.
OBSPutObjectWithFileRequest *request = [[OBSPutObjectWithFileRequest alloc]initWithBucketName:@"bucketname" objectKey:@"objectname" uploadFilePath:filePath];
    
// Set the type for the object.
request.contentType = OBSContentTypeMP4;
    
[client putObject:request completionHandler:^(OBSPutObjectResponse *response, NSError *error){
    NSLog(@"%@",response.etag);
}];

You can also set the customContentType field to specify the type for an object to be uploaded. Sample code is as follows:

static OBSClient *client;
NSString *endPoint = @"your-endpoint";
// Hard-coded or plaintext AK/SK are risky. For security purposes, encrypt your AK/SK and store them in the configuration file or environment variables. In this example, the AK/SK are stored in environment variables for identity authentication. Before running this example, configure environment variables AccessKeyID and SecretAccessKey.
// Obtain an AK/SK pair on the management console. For details, see https://support.huaweicloud.com/intl/en-us/usermanual-ca/ca_01_0003.html.
char* ak_env = getenv("AccessKeyID");
char* sk_env = getenv("SecretAccessKey");
NSString *AK = [NSString stringWithUTF8String:ak_env];
NSString *SK = [NSString stringWithUTF8String:sk_env];

// Initialize identity authentication.
OBSStaticCredentialProvider *credentialProvider = [[OBSStaticCredentialProvider alloc] initWithAccessKey:AK secretKey:SK];
    
//Initialize service configuration.
OBSServiceConfiguration *conf = [[OBSServiceConfiguration alloc] initWithURLString:endPoint credentialProvider:credentialProvider];
    
// Initialize an instance of OBSClient.
client = [[OBSClient alloc] initWithConfiguration:conf];
NSString *filePath = [[NSBundle mainBundle]pathForResource:@"fileName" ofType:@"mp4"];
//Upload a file.
OBSPutObjectWithFileRequest *request = [[OBSPutObjectWithFileRequest alloc]initWithBucketName:@"bucketname" objectKey:@"objectname" uploadFilePath:filePath];
    
// Set the type for the object.
request.customContentType = @"video/mp4";
    
[client putObject:request completionHandler:^(OBSPutObjectResponse *response, NSError *error){
    NSLog(@"%@",response.etag);
}];

• The contentType parameter supports 11 object types listed in the preceding table. If no type is specified, the default type binary/octet-stream is used.
• Different from contentType, customContentType allows you to use character strings to specify any type of objects to be uploaded. If this parameter is not set, the object type is determined by the value of contentType upon upload.
• If both customContentType and contentType are specified, the type of the object to be uploaded is determined by customContentType.