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.

Property Name	Description	Default Value
contentMD5	Indicates the base64-encoded digest of the object data. It is provided to the OBS server to verify data integrity.	N/A
storageClass	Indicates the storage class of the object. Different storage classes meet different needs for storage performance and costs. The value defaults to be the same as the object's residing bucket and can be changed.	OBS Standard
metaDataDict	Indicates the user-defined description of properties of the object uploaded to the bucket. It is used to facilitate the customized management on the object.	N/A
contentType	Indicates the MIME type of the object specified during upload, which defines the type and network code of the object as well as in which mode and coding will the browser read the object.	Binary stream
customContentType	Indicates the MIME type of the object specified during upload, which defines the type and network code of the object. Different from the contentType, this parameter allows the input of any characters to specify the MIME type of the object to be uploaded.	N/A

Setting the MD5 Value for an Object

You can set contentMD5 to specify the MD5 value for an object. 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/eu/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.

Setting the Storage Class for an Object

You can set storageClass to specify the storage class for an object. 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/eu/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.

Customizing Metadata for an Object

You can set metaDataDict to customize metadata for an object. 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/eu/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.

Setting the Type for an Object to Be Uploaded

You can set contentType to specify the type for an object. 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/eu/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);
}];

Type	Enumeration Value in OBS iOS SDK
video/mp4	OBSContentTypeMP4
text/html	OBSContentTypeHTML
image/png	OBSContentTypePNG
image/jpeg	OBSContentTypeJPEG
image/gif	OBSContentTypeGIF
application/pdf	OBSContentTypePDF
audio/mp3	OBSContentTypeMP3
audio/wav	OBSContentTypeWAV
binary/octet-stream	OBSContentTypeBinary
video/quicktime	OBSContentTypeMOV
application/vnd.apple.mpegurl	OBSContentTypeM3U8

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/eu/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.