Ok in simulator but throwing exception in ios device - iphone

Question

when i am running my app in the simulator everything is working perfectly .But when i running the same app in the Ipad exception is being thrown.
Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'data parameter is nil.
In my app at one step i have to request a web-URl and need to parsed the returned JSON response. But I have checked the web-url and have been able to parse perfectly in simulator. But all the problem has been arisen in real ios device.But I think i have identified the code where it is getting wrong.
+ (NSDictionary*) getParsedJSON:(NSString*) urlString {
NSLog(#"################################################################################");
NSLog(#"getParsedJSON => urlString:");
NSLog(#"%#", urlString);
NSURL* url = [NSURL URLWithString:urlString];
NSURLRequest* request = [NSURLRequest requestWithURL:url];
NSURLResponse *response1 = nil;
NSError *error = nil;
NSData* response = [NSURLConnection sendSynchronousRequest:request returningResponse:&response1 error:&error];
//NSData* response = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
NSLog(#"--------------------------------------------------------------------------------");
NSString* responseString = [[NSString alloc] initWithData:response encoding:NSUTF8StringEncoding];
NSLog(#"getParsedJSON => responseString:\n%#", responseString);
NSLog(#"--------------------------------------------------------------------------------");
NSError* jsonParsingError = nil;
NSDictionary* parsedJSON = [NSJSONSerialization JSONObjectWithData:response options:0 error:&jsonParsingError]; // here is place where exception seems to be thrown.
if (jsonParsingError) {
NSLog(#"ERROR in parsing JSON: %#", jsonParsingError);
} else {
NSLog(#"getParsedJSON => parsedJSON: \n%#", [parsedJSON description]);
}
NSLog(#"################################################################################");
return parsedJSON;
}
I have identified the line where it seems to be wrong .I have also attached screen shot of the exception report..Hoping for your experienced reply.

Answer 1

AS we can see from the logs your response string is null while you are using it on your Device. This may be due to some internet access problem. Try to Use:
if([response isequaltostring:#"(null)"]||response == nil || response.length == 0)
{
NSError* jsonParsingError = nil;
NSDictionary* parsedJSON = [NSJSONSerialization JSONObjectWithData:response options:0 error:&jsonParsingError]; // here is place where exception seems to be thrown.
if (jsonParsingError) {
NSLog(#"ERROR in parsing JSON: %#", jsonParsingError);
}
else {
NSLog(#"getParsedJSON => parsedJSON: \n%#", [parsedJSON description]);
}
}
Also try to add the exceptional breakpoint and post where exactly the app crashed.
Let me know the result.

Answer 2

First, you need to set an exception breakpoint in Xcode - there are many posts here on how to do that. Second, after each of you statements where an object is created or returned, add an assert:
NSURL *foo = ...
assert(foo);
Doing this will help you find the first issue not the last one.

Answer 3

As per your logs, your response string is empty!
Do the below two things!
Add NSLog(#"Response Data: %#",response); and check if the response has value?
If 'response' has value, convert it to a string - Log the string value - And check if the any of the key has nil value?
'NSJSONSerialization JSONObjectWithData' method would crash if it finds any key with nil value.