Crash on [responseData setLength:0]; - iphone

Question

I am making a async request and I'm getting a EXC_BAD_ACCESS on [responseData setLength:0];
The Code is:
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
[responseData setLength:0];
}
-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
[responseData appendData:data];
}
-(void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
NSLog(#"Connection failed: %#", [error description]);
}
-(void)connectionDidFinishLoading:(NSURLConnection *)connection {
NSString *responseString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
[responseData release];
luckyNumbers1 = [responseString JSONValue];
NSUserDefaults *information = [NSUserDefaults standardUserDefaults];
/*NSArray *luckyNumbers = [json objectWithString:responseString error:&error];*/
NSLog(#"luckyNumbers1: %#", luckyNumbers1);
NSLog(#"user Info array is: %#", luckyNumbers1);
// [information setObject:[NSString stringWithFormat:#"%#", (NSString *)[luckyNumbers1 objectForKey:#"session"]] forKey:#"sessionID"];
NSDictionary *array = (NSDictionary *)[luckyNumbers1 objectForKey:#"data"];
NSEnumerator *inner = [luckyNumbers1 objectEnumerator];
id value;
while((value = [inner nextObject])) {
NSLog(#"user Info array is: %#", value);
if ( [value isKindOfClass:[NSDictionary class]] ) {
[information setObject:[value objectForKey:#"id"] forKey:#"userID"];
NSLog(#"uid is: %#", [value objectForKey:#"id"]);
[information setObject:[NSString stringWithFormat:#"%#", (NSString *)[value objectForKey:#"points_all"]] forKey:#"pointString"];
[information setObject:[NSString stringWithFormat:#"%#", (NSString *)[[[value objectForKey:#"leaderboards"] objectForKey:#"all"] objectForKey:#"position"]] forKey:#"rankString"];
if ((NSNull *)[value objectForKey:#"display_name"] == [NSNull null]) {
[information setObject:#"No Display Name" forKey:#"displayNameString"];
} else {
[information setObject:[NSString stringWithFormat:#"%#", (NSString *)[value objectForKey:#"display_name"]] forKey:#"displayNameString"];
}
if ((NSNull *)[value objectForKey:#"level"] == [NSNull null]) {} else {
[information setObject:[NSString stringWithFormat:#"%#", (NSString *)[[[value objectForKey:#"level"] objectForKey:#"definition"] objectForKey:#"name"]] forKey:#"levelString"];
}
pointsTV = [[UILabel alloc] initWithFrame:CGRectMake(222, 294, 441, 22)];
pointsTV.text = [NSString stringWithFormat:#"Points: %#", [information stringForKey:#"pointString"]];
pointsTV.backgroundColor = [UIColor clearColor];
pointsTV.textColor = [UIColor whiteColor];
[TVWindow addSubview:pointsTV];
rankLabelTV = [[UILabel alloc] initWithFrame:CGRectMake(222, 269, 441, 22)];
rankLabelTV.backgroundColor = [UIColor clearColor];
rankLabelTV.textColor = [UIColor whiteColor];
rankLabelTV.text = [NSString stringWithFormat:#"Rank: %#", (NSString *)[[[array objectForKey:#"leaderboards"] objectForKey:#"all"] objectForKey:#"position"]];
[TVWindow addSubview:rankLabelTV];
levelNameLabelTV = [[UILabel alloc] initWithFrame:CGRectMake(222, 244, 441, 22)];
levelNameLabelTV.backgroundColor = [UIColor clearColor];
levelNameLabelTV.textColor = [UIColor whiteColor];
if ((NSNull *)[value objectForKey:#"level"] == [NSNull null]) {
levelNameLabelTV.text = #"No Level";
} else {
levelNameLabelTV.text = [NSString stringWithFormat:#"Level: %#", (NSString *)[[[array objectForKey:#"level"] objectForKey:#"definition"] objectForKey:#"name"]];
}
[TVWindow addSubview:levelNameLabelTV];
pointLabel.text = [information stringForKey:#"pointString"];
pointLabel.textAlignment = UITextAlignmentLeft;
displayNameLabelTV.text = [information stringForKey:#"displayNameString"];
displayNameLabel. text = [information stringForKey:#"displayNameString"];
rankLabel.text = [information stringForKey:#"rankString"];
levelLabel.text = [information stringForKey:#"levelString"];
NSURL *url1 = [NSURL URLWithString: [NSString stringWithFormat:#"%#", (NSString *)[array objectForKey:#"picture_url"]]];
NSData *urlData1 = [NSData dataWithContentsOfURL:url1];
UIImage *image1 = [UIImage imageWithData:urlData1];
profilePicture.image = image1;
profilePictureTV.image = image1;
[information setObject:[NSString stringWithFormat:#"%#", (NSString *)[luckyNumbers1 objectForKey:#"session"]] forKey:#"sessionID"];
}}
NSURLRequest *request2;
request2 = [NSURLRequest requestWithURL:[NSURL URLWithString:[NSString stringWithFormat:#"http://%#/api/widgets/%#/%#/players/%#/rewards.json", [information stringForKey:#"host"], [information objectForKey:#"apiKey"], [information objectForKey:#"URL"], [information objectForKey:#"userID"]]]];
NSLog(#"Badges Request is: %#", request2);
NSURLConnection *connection2;
connection2 = [[NSURLConnection alloc] initWithRequest:request2 delegate:self startImmediately:YES];
NSURLResponse *resp3;
NSData *cData2 = [NSURLConnection sendSynchronousRequest:request2 returningResponse:&resp3 error:nil];
NSString *cDataString2 = [[NSString alloc] initWithData:cData2 encoding:NSUTF8StringEncoding];
[self getUsersBadges: cDataString2];
[[NSURLConnection alloc] initWithRequest:request2 delegate:self];
// pass cDataString into the JSON parser and update points
[connection release];
}

Answer 1

Without seeing your initialization of reponseData, it’s hard to be sure, but I would guess that you’re either declaring it as [NSMutableData data] (which will get autoreleased) or release/autoreleaseing it before you get to -connection:didReceiveResponse:. The solution is to make sure it doesn’t get released early, either by calling retain on it or by initializing it with [[NSMutableData alloc] init]. In either case, you’ll need to release it once you’re done, though it looks as if you’re doing that already in your -connectionDidFinishLoading:, so no change needed there.