如何在iOS中使用JSON发送POST数据？

I tried to add an entry to db using a POST request in Objectve-C. My service is:

我试图在Objectve-C中使用POST请求向db添加一个条目。我的服务是:

@RequestMapping(method = RequestMethod.POST, headers = "content-type=application/json")
public
@ResponseBody
boolean addEmployee(@ModelAttribute User user) {
    try {
        logger.log(Level.INFO, user.getCountry());
        userDataService.addUser(user);

        return true;
        //return new Status(1, "Employee added Successfully !");
    } catch (Exception e) {
        e.printStackTrace();
        return false;//new Status(0, e.toString());
    }

}

When I try this on Postman, it's working fine with x-www-form-urlencoded. But when I try this in Objective-C, nothing happens. Here is what I tried:

当我在Postman上尝试这个时,它可以正常使用x-www-form-urlencoded。但是当我在Objective-C中尝试这个时,没有任何反应。这是我尝试过的:

NSString *jsonInputString = @"{\"userName\":\"abcd\"}";

NSString *jsonRequest = jsonInputString;

NSLog(@"jsonRequest is %@", jsonRequest);

NSURL *url = [NSURL URLWithString:@"http://localhost:8080/user"];

NSOperationQueue *queue = [[NSOperationQueue alloc] init];

NSMutableURLRequest *rq = [NSMutableURLRequest requestWithURL:url];
[rq setHTTPMethod:@"POST"];

NSData *jsonData = [jsonInputString dataUsingEncoding:NSUTF8StringEncoding];
[rq setHTTPBody:jsonData];

[rq setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];
[rq setValue:[NSString stringWithFormat:@"%ld", (long)[jsonData length]] forHTTPHeaderField:@"Content-Length"];

[NSURLConnection sendAsynchronousRequest:rq queue:queue completionHandler:^(NSURLResponse *response, NSData *data, NSError *error)
{
    NSLog(@"%@", [error localizedDescription]);
}];

In completion block, the log prints "Could not connect to the server". How can I call the service with JSON data?

在完成块中,日志打印“无法连接到服务器”。如何使用JSON数据调用服务?

1 个解决方案

#1

Something like this should work

// 1: Create your URL, Session config and Session

NSString *jsonInputString = @"{\"userName\":\"abcd\"}";

NSString *jsonRequest = jsonInputString;

NSURL *url = [NSURL URLWithString:@"http://localhost:8080/user"];

  NSURLSessionConfiguration *config =
      [NSURLSessionConfiguration defaultSessionConfiguration];
  NSURLSession *session = [NSURLSession sessionWithConfiguration:config];

  // 2: Create NSMutableRequest object
  NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:url];
  request.HTTPMethod = @"POST";

  // 3: Create Jsondata object
  NSError *error = nil;
 NSData *jsonData = [jsonInputString dataUsingEncoding:NSUTF8StringEncoding];

  // Asynchronously Api is hit here
  NSURLSessionUploadTask *dataTask =
      [session uploadTaskWithRequest:request
                            fromData:data
                   completionHandler:^(NSData *data, NSURLResponse *response,
                                       NSError *error) {

                       NSLog(@"%@", data);

                       NSDictionary *json =
                           [NSJSONSerialization JSONObjectWithData:data
                                                           options:0
                                                             error:nil];
                       NSLog(@"%@", json);
                       success(json);
                   }];

  [dataTask resume]; // Executed First