[置顶] 网络请求库的代码迁移

今天刚上班,群里不停有人发这东西:

不过估计到时候不进行代码迁移的话估计就不能兼容IPV6-only标准了,然后就不能上架appstore.可怜我还在用着NSURLConnection的废弃api,没办法了,只能迁移了,可是有不少同学可能跟我处于一个比较尴尬的境地,如果我们只是单纯的自己对AF进行封装,只要升级AF到3.0以上,就可以满足苹果的要求了,但是如果我们用来一些对AF二次封装的框架,就显得比较麻烦了,例如有的同学会用唐巧的猿题库网络框架,这些框架都是没有迁移到AF3.0的,这篇文章,我会以一个GJNetWorking的库讲解一下我的迁移经历.
我们来对比一下2.x和3.x都发生了什么变化:

AF2.x

AF3.x

由此可见:被苹果官方废弃的NSURLConnection已经被AF删掉了.所以我们应该面向AFHTTPSessionManager编程 而非AFHTTPRequestOperationManager.
介绍一下GJNetWorking,当时使用它来进行项目开发 主要是因为代码比较简洁,支持网络缓存,支持mjestension和mantle的模型映射.我们进行升级AF,主要是对GJHTTPManager GJBaseRequest GJModelRequest这几个类进行代码修改.在GJHTTPManager中使用AFHTTPSessionManager替换掉原来的AFHTTPRequestOperationManager

//原来的AFHTTPRequestOperationManager
AFHTTPRequestOperation *startOperation = nil;

switch (method) {
case GJRequestGET:
{
startOperation = [self.manager GET:url
            parameters:parameters
               success:^(AFHTTPRequestOperation *operation, id responseObject) {
                   [self requestFinishedWithOperation:operation request:request];
               } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
                   [self requestFinishedWithOperation:operation request:request];
             }];
}
break;

//修改后的的AFHTTPSessionManager

    NSURLSessionDataTask *startOperation = nil;

    switch (method) {
        case GJRequestGET:
        {


            startOperation = [self.manager GET:url parameters:parameters success:^(NSURLSessionDataTask * _Nonnull task, id  _Nullable responseObject) {
                [self requestFinishedWithOperation:task request:request resonseObj:responseObject];

            } failure:^(NSURLSessionDataTask * _Nullable task, NSError * _Nonnull error) {
                [self requestFinishedWithOperation:task request:request resonseObj:nil];

            }];

        }
            break;

不过比较难的是响应数据的处理,由于在2.0时代作者使用AFHTTPRequestOperation作为返回的结果处理缓存 和模型映射,3.0中这已经被删除了,所以我们只能换一种思路:直接处理从AFHTTPSessionManager

- (NSURLSessionDataTask *)GET:(NSString *)URLString
                   parameters:(id)parameters
                      success:(void (^)(NSURLSessionDataTask *task, id responseObject))success
                      failure:(void (^)(NSURLSessionDataTask *task, NSError *error))failure

方法中返回的responseObject.
GJBaseRequest中增加方法实现

- (void)requestCompletedWithModel:(id)model;

GJModelRequest中修改方法实现

- (void)requestCompletedWithObj:(id)obj andModelObjBlock:(void (^)(id model))modelBlock{

    [super requestCompletedWithObj:obj andModelObjBlock:modelBlock];

    BOOL success = !self.error;

    id responseStatus;
    id responseObject = obj;

    //if request success and request implement modelClass,
    //when request or default modelMaker implement the delegate ,
    //the response object will be make to model or model list.
    if (success && [self respondsToSelector:@selector(modelClass)]){
        Class defaultModelMaker = [GJNetworkingConfig modelMaker];
        Class modelMaker = nil;
        if (self && [[self class] respondsToSelector:@selector(makeModelWithJSON:class:status:)] &&
            [[self class] conformsToProtocol:@protocol(GJModelMakerDelegate)]) {
            modelMaker = [self class];
        }
        else if (defaultModelMaker && [defaultModelMaker respondsToSelector:@selector(makeModelWithJSON:class:status:)] &&
                 [defaultModelMaker conformsToProtocol:@protocol(GJModelMakerDelegate)]){
            modelMaker = defaultModelMaker;
        }

        if (modelMaker) {
            id model = [modelMaker makeModelWithJSON:responseObject
                                                         class:[self modelClass]
                                                        status:&responseStatus];

            modelBlock(model);
            self.status = responseStatus;
        }

    }

}