NSURLConnectionデフォルトのHTTPヘッダ

- (void)send
{
  NSMutableURLRequest *req = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"http://ifconfig.me"]];
  NSLog(@"Accept-Encoding: %@", [req valueForHTTPHeaderField:@"Accept-Encoding"]);
  NSURLConnection *connection = [NSURLConnection connectionWithRequest:req delegate:self];
  [connection start];
}

- (NSURLRequest *)connection:(NSURLConnection *)connection willSendRequest:(NSURLRequest *)request redirectResponse:(NSURLResponse *)response
{
  NSLog(@"Accept-Encoding: %@", [request valueForHTTPHeaderField:@"Accept-Encoding"]);
  return request;
}

がこうなる。

2014-08-06 16:45:33.576 URLCache[299:60b] Accept-Encoding: (null)
2014-08-06 16:45:33.648 URLCache[299:60b] Accept-Encoding: gzip, deflate

po [request allHTTPHeaderFields] は

po [request allHTTPHeaderFields]
{
    Accept = "*/*";
    "Accept-Encoding" = "gzip, deflate";
    "Accept-Language" = "ja-jp";
}

送られてるHTTPヘッダ。URLCacheはアプリ名。

Host                    ifconfig.me
Accept-Encoding         gzip, deflate
Accept                  */*
Accept-Language         ja-jp
Connection              keep-alive
User-Agent              URLCache/1.0 CFNetwork/672.0.8 Darwin/14.0.0