Replacement for AFJSONRequestOperation in AFNetwor

问题:

I am making a basic iPhone app with HTML Requests, by following this tutorial.

The tutorial has me using AFJSONRequestOperation in AFNetworking. The trouble is, I'm using AFNetworking version 2, which no longer has AFJSONRequestOperation.

So, of course, this code (from about half-way down the tutorial, under the heading "Querying the iTunes Store Search API") doesn't compile:

NSURL *url = [[NSURL alloc]
    initWithString:
    @"http://itunes.apple.com/search?term=harry&country=us&entity=movie"];
NSURLRequest *request = [[NSURLRequest alloc] initWithURL:url];
AFJSONRequestOperation *operation =
    [AFJSONRequestOperation JSONRequestOperationWithRequest:request
    success:^(NSURLRequest *request, NSHTTPURLResponse *response, id JSON) {
        NSLog(@"%@", JSON);
    } failure:^(NSURLRequest *request, NSHTTPURLResponse *response,
        NSError *error, id JSON) {
            NSLog(@"Request Failed with Error: %@, %@", error, error.userInfo);
    }];
[operation start];

My question is, what do I replace AFJSONRequestOperation with so that I can keep working with AFNetworking 2.x? I've googled this and found that no one else seems to be asking this question.

回答1:

Could you use AFHTTPSessionManger? So something like

AFHTTPSessionManager *manager = [AFHTTPSessionManager manager];
manager.requestSerializer = [AFJSONRequestSerializer serializer];
[manager GET:[url absoluteString]
  parameters:nil
     success:^(NSURLSessionDataTask *task, id responseObject) {
         NSLog(@"JSON: %@", responseObject);
     }
     failure:^(NSURLSessionDataTask *task, NSError *error) {
        // Handle failure
     }];

Another alternative could be to use AFHTTPRequestOperation and again set the responseSerializer to [AFJSONResponseSerializer serializer]. So something like

AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] 
                                            initWithRequest:request];
operation.responseSerializer = [AFJSONResponseSerializer serializer];
[operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation
                                                        , id responseObject) {
    NSLog(@"JSON: %@", responseObject);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
    // Handle error
}];

回答2:

From NSHipster's article on AFNetworking 2:

One of the breakthroughs of AFNetworking 2.0's new architecture is use of serializers for creating requests and parsing responses. The flexible design of serializers allows for more business logic to be transferred over to the networking layer, and for previously built-in default behavior to be easily customized.

In AFNetworking 2, serializers (the objects that turn HTTP data into usable Objective C objects) are now separate objects from the request operation object.

AFJSONRequestOperation, etc. therefore no longer exist.

From the AFJSONResponseSerializer docs:

AFJSONResponseSerializer is a subclass of AFHTTPResponseSerializer that validates and decodes JSON responses.

There are a few ways to hit the API you mentioned. Here's one:

NSURL *url = [[NSURL alloc] initWithString:@"http://itunes.apple.com/search?term=harry&country=us&entity=movie"];
NSURLRequest *request = [[NSURLRequest alloc] initWithURL:url];
AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:request];
[operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
    NSLog(@"success: %@", operation.responseString);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
    NSLog(@"error: %@",  operation.responseString);
}];

[operation start];