Convert NSArray of bytes to NSData

Question

I'm trying to download a file in Objective-C from a REST service but having some issues. Right now, the service returns a byte[] in JSON. I was able to get the array by using the json-framework.

NSURL *url = [NSURL URLWithString:@"http://192.168.10.215:8888/Service/RO/GetAllTheBytes/test.txt"];
NSString *str = [[NSString alloc] initWithContentsOfURL:url];
NSDictionary *jsonDic = [str JSONValue];
NSArray *fileContents = [jsonDic objectForKey:@"fileContents"];

Now I want to use this array of bytes to create a file, but I'm having trouble creating the file. Should I convert the NSArray to NSData, and how?

Why do you save fileContents in `NSArray`? I suppose `NSString` will be better choose. And `NSString` can be converted to byte[] when you need this — Nekto, Sep 07 '11 at 20:16
Possible duplicate http://stackoverflow.com/questions/1286212/how-to-convert-nsarray-to-nsdata — 0x8badf00d, Sep 07 '11 at 20:16
JSON doesn't have a byte type. Are you getting back maybe an array of numbers, a string of hexadecimal digits, a base64 encoded string, or something else? — Tommy, Sep 07 '11 at 20:25

score 1 · Answer 1 · answered Sep 08 '11 at 02:36

Change your service to return a Base64 string. There are a bunch of Objective-C Base64 decoders out there, some of which are half-decent.

A NSArray of NSNumbers is really really really stupid, with a minimum space overhead of about 300% (although not quite as bad as JRA-11693).

Convert NSArray of bytes to NSData

1 Answers1