NSJSONSerialization parsing error neither dictionary nor array - objective-c

Question

i am succesfully getting data from my server. and after getting it i send the data to the function to parse;
- (void)readIn:(NSMutableData *)s {
NSLog(#"Reading in the following:");
NSString * prints = [[NSString alloc] initWithData:s encoding:NSUTF8StringEncoding];
NSLog(#"%#", prints);
NSError *error = nil;
NSData *jsonData = [[NSData alloc] initWithData:s];
if (jsonData) {
id jsonObjects = [NSJSONSerialization JSONObjectWithData:jsonData options:NSJSONReadingMutableContainers error:&error];
if ([jsonObjects isKindOfClass: [NSArray class]])
NSLog(#"yes we got an Array");
else if ([jsonObjects isKindOfClass: [NSDictionary class]])
NSLog(#"yes we got an dictionary");
else
NSLog(#"neither array nor dictionary!");
if (error) {
NSLog(#"error is %#", [error localizedDescription]);
return;
}
NSArray *keys = [jsonObjects allKeys];
for (NSString *key in keys) {
NSLog(#"%# is %#",key, [jsonObjects objectForKey:key]);
}
} else {
// Handle Error
}
}
now my print on console is:
2012-08-17 13:59:57.667 TaraftarlikOyunu[1157:c07] Reading in the following:
2012-08-17 13:59:57.667 TaraftarlikOyunu[1157:c07] {"uID":"5878341","tm":"fb","hh":122,"pt":75,"coin":500,"ll":1,"qlevel":1,"coect":true,"potWeekly":{"pts":75,"intval":604800000},"acent":{"chamunt":0},"mes":[]}
2012-08-17 13:59:57.668 TaraftarlikOyunu[1157:c07] neither array nor dictionary!
2012-08-17 13:59:57.670 TaraftarlikOyunu[1157:c07] error is The operation couldn’t be completed. (Cocoa error 3840.)
it seems legal json object to me. where am i doing wrong?
i am getting data from the server with nsstream; and here is my code to get data:
case NSStreamEventHasBytesAvailable: {
if(stream == inputStream) {
NSLog(#"inputStream is ready.");
uint8_t buf[1024];
unsigned int len = 0;
len = [inputStream read:buf maxLength:1024];
NSLog(#"length %i", len);
if(len > 0) {
NSMutableData* data=[[NSMutableData alloc] initWithLength:0];
[data appendBytes: (const void *)buf length:len];
[self readIn:data];
}
}
break;
}

Answer 1

Try explicitly setting the jsonObjects to be an array:
NSError *myError = nil;
NSArray *jsonObjects= [NSJSONSerialization JSONObjectWithData:responseData ptions:NSJSONReadingMutableLeaves error:&myError];
for (NSDictionary * dict in jsonObjects) {
NSLog(#"Some data %#", [dict objectForKey:#"field"]);
//replace this to access a valid field
}

Answer 2

The reason for the failure is that the original data probably has some '\' characters in it quoting '"' characters. If you had searched on "Cocoa error 3840" you would have gotten a hint on this. What I suggest you do is print out the original data, one character at a time (its ascii so no need for UTF) and verify this.
char *ptr = [s bytes];
for(int i=0; i<[s length]; ++i) NSLog(#"%c ", *ptr++);

Answer 3

problem is that, json string i get is coming with null termination at the end and when i try to deserialize it it can not be converted to NSDictionary or NSArray. making a little change on the code makes everything perfect. the true code should be like that
case NSStreamEventHasBytesAvailable: {
if(stream == inputStream) {
NSLog(#"inputStream is ready.");
uint8_t buf[1024];
unsigned int len = 0;
len = [inputStream read:buf maxLength:1024];
NSLog(#"length %i", len);
if(len > 0) {
datum =[[NSMutableData alloc] initWithLength:0];
[datum appendBytes: (const void *)buf length:len-1];
NSDictionary * jsondict = [NSJSONSerialization JSONObjectWithData:datum options:NSUTF8StringEncoding error:nil];
NSLog(#"is valid json object %d",[NSJSONSerialization isValidJSONObject:jsondict]);
[self readIn:datum];
}
}
else {
NSLog(#"no buffer!");
}
break;
}
default: {
NSLog(#"Stream is sending an Event: %i", event);
break;
}
}
only difference from the other one is i threw the last byte and it became valid json dictionary.
thanks for the people who are interested in my question.

Answer 4

JSON doesn't accept any control characters other than tab, form feed, carriage return, and line feed in a JSON document, so your code works perfectly fine and does exactly what it is supposed to do by not reading anything.
So where does that nul character come from? Either your code reading the data is wrong, or the server is wrong. Looks to me like the problem is the server. Your "fix" by throwing away the last character is bad - if the server is ever fixed, you'll throw away the closing brace. I'd contact whoever is responsible for the server and fix the problem there.