AFNetworking 3.0源码阅读

该篇是AFNetworking中网络框架部分的最后一部分AFHTTPSessionManager。

AFHTTPSessionManager是AFURLSessionManager的子类，提供通过提供basesURL来构建HTTP请求的便捷方法。仍旧是先从.h文件来读起。

AFHTTPSessionManager.h

用来拼接请求URL的基URL。构建出来的url在文件中的注释有提到，基本上有这些

 

http请求序列化器，不能为nil。

http响应序列化器，不能为nil。

安全策略，除非有特定说明，默认配置为“AFSSLPinningModePublicKey”或者“AFSSLPinningModeCertificate”，并且只应用于https初始化的会话。

三种初始化方法。 

 

GET请求，前者建议不再使用。 

HEAD请求。

 

普通POST请求，前者建议不再使用。

body包含数据流的POST请求，前者建议不再使用。

PUT请求。

PATCH请求。

DELETE请求。

AFHTTPSessionManager.m

再次定义baseURL，可以发现此处的修饰关键字为readwrite，而在.h文件中为readonly。目的是在外部只读，而在内部可以设置。

这里使用@dynamic关键字修饰属性responseSerializer，@dynamic关键字一般用于告知编译器setter和getter手动实现，而AFHTTPSessionManager是AFURLSessionManager的子类，也就是说要使用父类的默认实现。

初始化方法实现。

重写安全策略的set方法，请求非https请求抛出异常。

接着是各类http请求的实现，大同小异，全部贴在下面。

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

    return [self GET:URLString parameters:parameters progress:nil success:success failure:failure];
}

- (NSURLSessionDataTask *)GET:(NSString *)URLString
                   parameters:(id)parameters
                     progress:(void (^)(NSProgress * _Nonnull))downloadProgress
                      success:(void (^)(NSURLSessionDataTask * _Nonnull, id _Nullable))success
                      failure:(void (^)(NSURLSessionDataTask * _Nullable, NSError * _Nonnull))failure
{

    NSURLSessionDataTask *dataTask = [self dataTaskWithHTTPMethod:@"GET"
                                                        URLString:URLString
                                                       parameters:parameters
                                                   uploadProgress:nil
                                                 downloadProgress:downloadProgress
                                                          success:success
                                                          failure:failure];

    [dataTask resume];

    return dataTask;
}

//HEAD
- (NSURLSessionDataTask *)HEAD:(NSString *)URLString
                    parameters:(id)parameters
                       success:(void (^)(NSURLSessionDataTask *task))success
                       failure:(void (^)(NSURLSessionDataTask *task, NSError *error))failure
{
    NSURLSessionDataTask *dataTask = [self dataTaskWithHTTPMethod:@"HEAD" URLString:URLString parameters:parameters uploadProgress:nil downloadProgress:nil success:^(NSURLSessionDataTask *task, __unused id responseObject) {
        if (success) {
            success(task);
        }
    } failure:failure];

    [dataTask resume];

    return dataTask;
}

//POST
- (NSURLSessionDataTask *)POST:(NSString *)URLString
                    parameters:(id)parameters
                       success:(void (^)(NSURLSessionDataTask *task, id responseObject))success
                       failure:(void (^)(NSURLSessionDataTask *task, NSError *error))failure
{
    return [self POST:URLString parameters:parameters progress:nil success:success failure:failure];
}

- (NSURLSessionDataTask *)POST:(NSString *)URLString
                    parameters:(id)parameters
                      progress:(void (^)(NSProgress * _Nonnull))uploadProgress
                       success:(void (^)(NSURLSessionDataTask * _Nonnull, id _Nullable))success
                       failure:(void (^)(NSURLSessionDataTask * _Nullable, NSError * _Nonnull))failure
{
    NSURLSessionDataTask *dataTask = [self dataTaskWithHTTPMethod:@"POST" URLString:URLString parameters:parameters uploadProgress:uploadProgress downloadProgress:nil success:success failure:failure];

    [dataTask resume];

    return dataTask;
}

- (NSURLSessionDataTask *)POST:(NSString *)URLString
                    parameters:(nullable id)parameters
     constructingBodyWithBlock:(nullable void (^)(id<AFMultipartFormData> _Nonnull))block
                       success:(nullable void (^)(NSURLSessionDataTask * _Nonnull, id _Nullable))success
                       failure:(nullable void (^)(NSURLSessionDataTask * _Nullable, NSError * _Nonnull))failure
{
    return [self POST:URLString parameters:parameters constructingBodyWithBlock:block progress:nil success:success failure:failure];
}

- (NSURLSessionDataTask *)POST:(NSString *)URLString
                    parameters:(id)parameters
     constructingBodyWithBlock:(void (^)(id <AFMultipartFormData> formData))block
                      progress:(nullable void (^)(NSProgress * _Nonnull))uploadProgress
                       success:(void (^)(NSURLSessionDataTask *task, id responseObject))success
                       failure:(void (^)(NSURLSessionDataTask *task, NSError *error))failure
{
    NSError *serializationError = nil;
    NSMutableURLRequest *request = [self.requestSerializer multipartFormRequestWithMethod:@"POST" URLString:[[NSURL URLWithString:URLString relativeToURL:self.baseURL] absoluteString] parameters:parameters constructingBodyWithBlock:block error:&serializationError];
    if (serializationError) {
        if (failure) {
            dispatch_async(self.completionQueue ?: dispatch_get_main_queue(), ^{
                failure(nil, serializationError);
            });
        }

        return nil;
    }

    __block NSURLSessionDataTask *task = [self uploadTaskWithStreamedRequest:request progress:uploadProgress completionHandler:^(NSURLResponse * __unused response, id responseObject, NSError *error) {
        if (error) {
            if (failure) {
                failure(task, error);
            }
        } else {
            if (success) {
                success(task, responseObject);
            }
        }
    }];

    [task resume];

    return task;
}

//PUT
- (NSURLSessionDataTask *)PUT:(NSString *)URLString
                   parameters:(id)parameters
                      success:(void (^)(NSURLSessionDataTask *task, id responseObject))success
                      failure:(void (^)(NSURLSessionDataTask *task, NSError *error))failure
{
    NSURLSessionDataTask *dataTask = [self dataTaskWithHTTPMethod:@"PUT" URLString:URLString parameters:parameters uploadProgress:nil downloadProgress:nil success:success failure:failure];

    [dataTask resume];

    return dataTask;
}

//PATCH
- (NSURLSessionDataTask *)PATCH:(NSString *)URLString
                     parameters:(id)parameters
                        success:(void (^)(NSURLSessionDataTask *task, id responseObject))success
                        failure:(void (^)(NSURLSessionDataTask *task, NSError *error))failure
{
    NSURLSessionDataTask *dataTask = [self dataTaskWithHTTPMethod:@"PATCH" URLString:URLString parameters:parameters uploadProgress:nil downloadProgress:nil success:success failure:failure];

    [dataTask resume];

    return dataTask;
}

//DELETE
- (NSURLSessionDataTask *)DELETE:(NSString *)URLString
                      parameters:(id)parameters
                         success:(void (^)(NSURLSessionDataTask *task, id responseObject))success
                         failure:(void (^)(NSURLSessionDataTask *task, NSError *error))failure
{
    NSURLSessionDataTask *dataTask = [self dataTaskWithHTTPMethod:@"DELETE" URLString:URLString parameters:parameters uploadProgress:nil downloadProgress:nil success:success failure:failure];

    [dataTask resume];

    return dataTask;
}

- (NSURLSessionDataTask *)dataTaskWithHTTPMethod:(NSString *)method
                                       URLString:(NSString *)URLString
                                      parameters:(id)parameters
                                  uploadProgress:(nullable void (^)(NSProgress *uploadProgress)) uploadProgress
                                downloadProgress:(nullable void (^)(NSProgress *downloadProgress)) downloadProgress
                                         success:(void (^)(NSURLSessionDataTask *, id))success
                                         failure:(void (^)(NSURLSessionDataTask *, NSError *))failure
{
    NSError *serializationError = nil;
    NSMutableURLRequest *request = [self.requestSerializer requestWithMethod:method URLString:[[NSURL URLWithString:URLString relativeToURL:self.baseURL] absoluteString] parameters:parameters error:&serializationError];
    if (serializationError) {
        if (failure) {
            dispatch_async(self.completionQueue ?: dispatch_get_main_queue(), ^{
                failure(nil, serializationError);
            });
        }

        return nil;
    }

    __block NSURLSessionDataTask *dataTask = nil;
    dataTask = [self dataTaskWithRequest:request
                          uploadProgress:uploadProgress
                        downloadProgress:downloadProgress
                       completionHandler:^(NSURLResponse * __unused response, id responseObject, NSError *error) {
        if (error) {
            if (failure) {
                failure(dataTask, error);
            }
        } else {
            if (success) {
                success(dataTask, responseObject);
            }
        }
    }];

    return dataTask;
}

值得一说的是当请求创建失败，如果没有设置completionQueue，回到主线程队列。

AFNetworking3.0的网络部分大致就阅读完了，可能不尽详细。库中还有一部分针对于UIKit的拓展，有时间补。

阅读该部分后认为需要补充学习记录：TCP/IP HTTP HTTPS。