Comments on: How to download and process GZip’d data

By: VSVasan

VSVasan — Sat, 19 Mar 2011 00:38:22 +0000

When the header “Accept-Encoding” is added, would the NSData received from NSURLConnection get decompressed automatically or do we need look at the header to see whaat the content encoding is and call the NSDataAddtions that someone wrote to decompress NSData in memory. I understand NSURLDownload supports gzip.

Thanks for your help in advance

By: Florian

Florian — Tue, 15 Mar 2011 15:20:29 +0000

I think the header should state “Accept-Encoding”, not “Accepts-Encoding”.
See http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html
Also, I think you meant to write:

response.setHeader(“Content-Encoding”, “gzip”);

not

request.setHeader(“Content-Encoding”, “gzip”);

Regards,
Florian

By: Mike Orlov

Mike Orlov — Thu, 14 May 2009 10:55:28 +0000

Check this link: http://www.clintharris.net/2009/how-to-gzip-data-in-memory-using-objective-c/

It contains absolutely clear and straight implementation for in-memory compressing NSData with gzip.

By: Pascal

Pascal — Wed, 28 Jan 2009 10:48:36 +0000

Yes, are there any experiences with compressing the data I’m going to send?

For the Java part, it’s straightforward how to manually decompress the content, but what do I have to insert here to compress the POST data?

(…)
NSMutableURLRequest* request = [[NSMutableURLRequest alloc] init];
[request setURL: serverURL];
[request setHTTPMethod:@"POST"];
[request setValue:@"text/xml; charset=utf-8" forHTTPHeaderField:@"Content-Type"];
[request addValue:@"gzip" forHTTPHeaderField:@"Accepts-Encoding"];

NSString *xmlRequest = [self getTheDataToPostAsXML];
[request setHTTPBody:[xmlRequest dataUsingEncoding:NSUTF8StringEncoding]];

NSURLConnection* connection = [[NSURLConnection alloc] initWithRequest:request delegate:self];
(…)

Thanks for your help,
Pascal

By: Aaron Hill

Aaron Hill — Sun, 11 Jan 2009 04:23:04 +0000

What about the inverse, gzip encoding on the phone before sending an HTTP post?

By: Rodney Aiglstorfer

Rodney Aiglstorfer — Thu, 16 Oct 2008 04:32:57 +0000

Although not required, it is recommended that you tell the webservice that you are a client capable of supporting gzip content. By default, even though the iPhone NSURLConnection is capable, it doesn’t add the required header to a request that will announce that fact formally.

To add the header to your request on iPhone you can do something like this

NSMutableURLRequest *request = …
[request addValue:@"gzip" forHTTPHeaderField:@"Accepts-Encoding"];