objective c parse json from url request

问题:

I am trying to parse a json string requested from an api located at: http://www.physics.leidenuniv.nl/json/news.php

However, i am having trouble parsing this json. I get the following error: Unexpected end of file during string parse

I have looked for hours, but I can not find an answer to this problem.

My code snippet:

In my viewDidLoad:

NSURLRequest *request = [NSURLRequest requestWithURL:
                         [NSURL URLWithString:@"http://www.physics.leidenuniv.nl/json/news.php"]];

[[NSURLConnection alloc] initWithRequest:request delegate:self];

The delegate:

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
NSMutableData *responseData = [[NSMutableData alloc] init];
[responseData appendData:data];

NSString *responseString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
NSError *e = nil;
NSData *jsonData = [responseString dataUsingEncoding:NSUTF8StringEncoding];
NSDictionary *JSON = [NSJSONSerialization JSONObjectWithData:jsonData options: NSJSONReadingMutableContainers error: &e];
}

Anybody know an answer to this problem so i can parse the json data?

回答1:

Do this way:

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
    // Append the new data to receivedData.
    // receivedData is an instance variable declared elsewhere.

    [responseData appendData:data];
}


- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
NSString *responseString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
NSError *e = nil;
NSData *jsonData = [responseString dataUsingEncoding:NSUTF8StringEncoding];
NSDictionary *JSON = [NSJSONSerialization JSONObjectWithData:jsonData options: NSJSONReadingMutableContainers error: &e];

}

回答2:

I would recommend doing it this way:

NSURLRequest *request = [[NSURLRequest alloc] initWithURL:[NSURL URLWithString:@"http://www.physics.leidenuniv.nl/json/news.php"]];

__block NSDictionary *json;
[NSURLConnection sendAsynchronousRequest:request
                                   queue:[NSOperationQueue mainQueue]
                       completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
                           json = [NSJSONSerialization JSONObjectWithData:data
                                                                  options:0
                                                                    error:nil];
                           NSLog(@"Async JSON: %@", json);
                       }];

Or if for whatever reason (not recommended) you want to run a synchronous request you could do:

NSData *theData = [NSURLConnection sendSynchronousRequest:request
                      returningResponse:nil
                                  error:nil];

NSDictionary *newJSON = [NSJSONSerialization JSONObjectWithData:theData
                                                        options:0
                                                          error:nil];

NSLog(@"Sync JSON: %@", newJSON);

回答3:

//call this method
-(void)syncWebByGETMethod
{
      [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:YES];
    NSString *urlString = [NSString stringWithFormat:@"http://www.yoursite.com"];
    NSURLRequest * request = [NSURLRequest requestWithURL:[NSURL URLWithString:urlString]];
   [NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue]                          completionHandler:^(NSURLResponse * response, NSData * data, NSError * connectionError)
        {
         if (data)
         {
             id myJSON;
             @try {
                 myJSON = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:nil];
             }
             @catch (NSException *exception) {
             }
             @finally {
             }
             jsonArray = (NSArray *)myJSON;

             NSLog(@"mmm %@",jsonArray);
         }
     }];
}

回答4:

Simple Way to store json-url data in dictionary.

 NSData *data=[NSData dataWithContentsOfURL:[NSURL URLWithString:@"https://query.yahooapis.com/v1/public/yql?q=select+%2A+from+weather.forecast+where+woeid%3D1100661&format=json"]];
    NSError *error=nil;
    id response=[NSJSONSerialization JSONObjectWithData:data options:
                 NSJSONReadingMutableContainers | NSJSONReadingMutableLeaves error:&error];

    if (error) {
        NSLog(@"%@",[error localizedDescription]);
    } else {
        _query = [response objectForKey:@"query"];
        NSLog(@"%@",_query); 

You can try this, so easy.

回答5:

One solution is to use NSURLConnection sendSynchronousRequest:returningResponse:error: (docs). In the completion handler you'll have ALL the response data, not just the partial data you get in the delegate's connection:didReceiveData: method.

If you want to keep using the delegate, you'll need to follow the advice in the Apple docs:

The delegate should concatenate the contents of each data object delivered to build up the complete data for a URL load.

回答6:

Volunteermatch API Objective C

i am using one common methods for AFNetworking WS Calling. Uses:

Call WS:

NSDictionary* param = @{
                        @"action":@"helloWorld",
                        @"query":@"{\"name\":\"john\"}"
                        };

[self requestWithUrlString:@"URL" parmeters:paramDictionary success:^(NSDictionary *response) {
    //code For Success
} failure:^(NSError *error) {
   // code for WS Responce failure
}];

Add Two Methods: this two methods are common,u can use these common method in whole project useing NSObject class. also add // define error code like...

define kDefaultErrorCode 12345

- (void)requestWithUrlString:(NSString *)stUrl parmeters:(NSDictionary *)parameters success:(void (^)(NSDictionary *response))success failure:(void (^)(NSError *error))failure {

[self requestWithUrl:stUrl parmeters:parameters success:^(NSDictionary *response) {
    if([[response objectForKey:@"success"] boolValue]) {
        if(success) {
            success(response);

        }
    }
    else {
        NSError *error = [NSError errorWithDomain:@"Error" code:kDefaultErrorCode userInfo:@{NSLocalizedDescriptionKey:[response objectForKey:@"message"]}];
        if(failure) {
            failure(error);
        }
    }
} failure:^(NSError *error) {
    if(failure) {
        failure(error);
    }
}];}

and // Set Headers in Below Method (if required otherwise remove)

- (void)requestWithUrl:(NSString *)stUrl parmeters:(NSDictionary *)parameters success:(void (^)(NSDictionary *response))success failure:(void (^)(NSError *))failure {

AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
[manager setResponseSerializer:[AFHTTPResponseSerializer serializer]];


[manager.requestSerializer setValue:@"WWSE profile=\"UsernameToken\"" forHTTPHeaderField:@"Authorization"];



[manager GET:stUrl parameters:parameters success:^(AFHTTPRequestOperation *operation, id responseObject) {
    if([responseObject isKindOfClass:[NSDictionary class]]) {
        if(success) {
            success(responseObject);
        }
    }
    else {
        NSDictionary *response = [NSJSONSerialization JSONObjectWithData:responseObject options:NSJSONReadingAllowFragments error:nil];
        if(success) {
            success(response);
        }
    }
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
    NSLog(@"Error: %@", error);
    if(failure) {
        failure(error);
    }
}];}

For any issues and more Detail please visit..AFNetworking

回答7:

-(void)getWebServic{
NSURL *url = [NSURL URLWithString:@"----URL----"];

// 2
NSURLSessionDataTask *downloadTask = [[NSURLSession sharedSession]
                                      dataTaskWithURL:url completionHandler:^(NSData *data, NSURLResponse *response, NSError *error)
{
    NSDictionary *jsonObject=[NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableLeaves error:nil];
    [self loadDataFromDictionary:(NSArray*)jsonObject];
    NSLog(@"data: %@",jsonObject);

}];

// 3
[downloadTask resume]; }