[置顶] iOS解读AFN查看请求头，判断响应成功、失败

AFN不管是GET、POST、PUT、DELETE请求，最终都会调用此方法 ，建立一个任务。

AFHTTPSessionManager.m

- (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) {
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wgnu"
dispatch_async(self.completionQueue ?: dispatch_get_main_queue(), ^{
failure(nil, serializationError);
});
#pragma clang diagnostic pop
}

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;
}

发送请求如下：
AFURLRequestSerialization.m

- (NSMutableURLRequest *)requestWithMethod:(NSString *)method
URLString:(NSString *)URLString
parameters:(id)parameters
error:(NSError *__autoreleasing *)error
{
NSParameterAssert(method);
NSParameterAssert(URLString);

NSURL *url = [NSURL URLWithString:URLString];

NSParameterAssert(url);

NSMutableURLRequest *mutableRequest = [[NSMutableURLRequest alloc] initWithURL:url];
mutableRequest.HTTPMethod = method;

for (NSString *keyPath in AFHTTPRequestSerializerObservedKeyPaths()) {
if ([self.mutableObservedChangedKeyPaths containsObject:keyPath]) {
[mutableRequest setValue:[self valueForKeyPath:keyPath] forKey:keyPath];
}
}

mutableRequest = [[self requestBySerializingRequest:mutableRequest withParameters:parameters error:error] mutableCopy];

return mutableRequest;
}

我们在控制台输出request时，只会得到一个URL，因此要想看到请求头，就具体打印po mutableRequest.allHTTPHeaderFields



AFURLResponseSerialization.m

- (instancetype)init {
self = [super init];
if (!self) {
return nil;
}

self.acceptableContentTypes = [NSSet setWithObjects:@"application/json", @"text/json", @"text/javascript", nil];

return self;
}

通过初始化方法可以看出来，AFNetworking支持的ContentType有：application/json;text/json;text/javascript 。

- (BOOL)validateResponse:(NSHTTPURLResponse *)response
data:(NSData *)data
error:(NSError * __autoreleasing *)error
{
BOOL responseIsValid = YES;
NSError *validationError = nil;

if (response && [response isKindOfClass:[NSHTTPURLResponse class]]) {
if (self.acceptableContentTypes && ![self.acceptableContentTypes containsObject:[response MIMEType]] &&
!([response MIMEType] == nil && [data length] == 0)) {

if ([data length] > 0 && [response URL]) {
NSMutableDictionary *mutableUserInfo = [@{
NSLocalizedDescriptionKey: [NSString stringWithFormat:NSLocalizedStringFromTable(@"Request failed: unacceptable content-type: %@", @"AFNetworking", nil), [response MIMEType]],
NSURLErrorFailingURLErrorKey:[response URL],
AFNetworkingOperationFailingURLResponseErrorKey: response,
} mutableCopy];
if (data) {
mutableUserInfo[AFNetworkingOperationFailingURLResponseDataErrorKey] = data;
}

validationError = AFErrorWithUnderlyingError([NSError errorWithDomain:AFURLResponseSerializationErrorDomain code:NSURLErrorCannotDecodeContentData userInfo:mutableUserInfo], validationError);
}

responseIsValid = NO;
}

if (self.acceptableStatusCodes && ![self.acceptableStatusCodes containsIndex:(NSUInteger)response.statusCode] && [response URL]) {
NSMutableDictionary *mutableUserInfo = [@{
NSLocalizedDescriptionKey: [NSString stringWithFormat:NSLocalizedStringFromTable(@"Request failed: %@ (%ld)", @"AFNetworking", nil), [NSHTTPURLResponse localizedStringForStatusCode:response.statusCode], (long)response.statusCode],
NSURLErrorFailingURLErrorKey:[response URL],
AFNetworkingOperationFailingURLResponseErrorKey: response,
} mutableCopy];

if (data) {
mutableUserInfo[AFNetworkingOperationFailingURLResponseDataErrorKey] = data;
}

validationError = AFErrorWithUnderlyingError([NSError errorWithDomain:AFURLResponseSerializationErrorDomain code:NSURLErrorBadServerResponse userInfo:mutableUserInfo], validationError);

responseIsValid = NO;
}
}

if (error && !responseIsValid) {
*error = validationError;
}

return responseIsValid;
}

通过statusCode==200来判断请求是否成功

查看响应头如下：

[manager POST:urlStr parameters:parameters progress:^(NSProgress * _Nonnull uploadProgress) {
} success:^(NSURLSessionDataTask * _Nonnull task, id  _Nullable responseObject) {
NSHTTPURLResponse *response = (NSHTTPURLResponse *)task.response;
NSDictionary *allHeaders = response.allHeaderFields;
NSLog(@"响应--%@\n响应头--%@",response,allHeaders);

success(responseObject);
} failure:^(NSURLSessionDataTask * _Nullable task, NSError * _Nonnull error) {
}];