Request headers (GET object)

The table below describes the headers you can use in a request to retrieve an object.

Request header Description Required
Authorization See Authentication. Yes
Date See Common request headers. Date or
x-amz-date
Host See Common request headers. Yes
If-Match

Specifies one or more values for comparison with the ETag of the specified object or object version. If the ETag matches one of the specified values, HCP continues processing the request. If the ETag doesn’t match any of the specified values, HCP returns a 412 (Precondition Failed) status code.

To specify the values for this header, use this format:

"value"[, "value"]...

In this format, each value can be any string of one or more characters and must be enclosed in double quotation marks (").

Alternatively, you can specify a single asterisk (*) as the value for the If-Match header. All ETags match an asterisk in an If-Match header.

No
If-Modified-Since

Specifies a date and time, in Greenwich Mean Time (GMT), for comparison with the date and time the specified object or object version was last modified. If the modification date and time is later than the specified date and time, HCP continues processing the request. If the modification date and time is equal to or earlier than the specified date and time, HCP returns a 304 (Not Modified) status code.

To specify the date and time for this header, use one of these formats:

DDD, dd MMM yyyy HH:mm:ss (+0000|GMT)

For example: Tue, 07 Feb 2017 14:27:05 +0000

DDDD, dd-MMM-yyyy HH:mm:ss (+0000|GMT)

For example: Tuesday, 07-Feb-17 14:27:05 +0000

DDD MMM d HH:mm:ss yyyy

For example: Tue Feb 7 14:27:05 2017

In these formats:

DDD is the three-letter abbreviation for the day of the week, with an uppercase first letter (for example, Mon).

DDDD is the day of the week fully spelled out, with an uppercase first letter (for example, Monday).

d is the one- or two-digit day of the month, as applicable.

dd is the two-digit day of the month.

MMM is the three-letter abbreviation for the month, with an uppercase first letter (for example, Feb).

yy is the last two digits of the year. HCP assumes that the intended year is within 80 years before or 20 years after the current year.

yyyy is the four-digit year.

HH is the hour on a 24-hour clock.

mm is the number of minutes.

ss is the number of seconds.

If the value specified by the If-Modified-Since header doesn’t conform to one of the formats shown above, the header is ignored.

No
If-None-Match

Specifies one or more values for comparison with the ETag of the specified object or object version. If the ETag doesn’t match any of the specified values, HCP continues processing the request. If the ETag matches any of the specified values, HCP returns a 304 (Not Modified) status code.

To specify the values for this header, use this format:

"value"[, "value"]...

In this format, each value can be any string of one or more characters and must be enclosed in double quotation marks (").

Alternatively, you can specify a single asterisk (*) as the value for the If-None-Match header. No ETags match an asterisk in an If-None-Match header.

No
If-Unmodified-Since

Specifies a date and time, in Greenwich Mean Time (GMT), for comparison with the date and time the specified object or object version was last modified. If the modification date and time is equal to or earlier than the specified date and time, HCP continues processing the request. If the modification date and time is later than the specified date and time, HCP returns a 412 (Precondition Failed) status code.

For valid values for this header, see the description of the If-Modified-Since header above.

No
Range Retrieves part of an object. For valid values for this header, see Retrieving an object. No
response-cache-control Specifies a value to be returned in the Cache-Control response header. No
response-content-
  disposition
Specifies a value to be returned in the Content-Disposition response header. No
response-content-
  encoding
Specifies a value to be returned in the Content-Encoding response header. No
response-content-
  language
Specifies a value to be returned in the Content-Language response header. No
response-content-type Specifies a value to be returned in the Content-Type response header. No
response-expires Specifies a value to be returned in the Expires response header. No
x-amz-date See Common request headers. x-amz-date or Date

© 2015, 2020 Hitachi Vantara LLC. All rights reserved.