小尝YTKNetwork

一、什么是YTKNetwork

YTKNetwork是一个基于AFNetworking的网络层封装。

二、包括那几个类

○  YTKBaseRequest

○  YTKRequest

○  YTKNetworkAgent

○  YTKNetworkConfig

△YTKNetwork的基本用法：基本用法，YTKNetwork 的基本的思想是把每一个网络请求封装成对象。所以使用 YTKNetwork，你的每一种请求都需要继承 YTKRequest类，通过覆盖父类的一些方法来构造指定的网络请求。

下面会分别讲解这几个类。

YTKNetworkAgent

网络请求的总代理类，是对AFNetworking的封装。此类是一个单例。

内部包含的三个成员变量：

AFHTTPRequestOperationManager *_manager;

AFHTTPRequestOperationManagerd的单例网路请求manager对象

YTKNetworkConfig *_config;

负责配置一个相关的设置

NSMutableDictionary *_requestsRecord;

请求队列

对外的接口有以下方法：

-(void)addRequest:(YTKBaseRequest *)request;

// 这里详细分析一下addRequest的内部实现

- (void)addRequest:(YTKBaseRequest *)request {

YTKRequestMethod method = [request requestMethod];

NSString *url = [self buildRequestUrl:request];

id param = request.requestArgument;

AFConstructingBlock constructingBlock = [request constructingBodyBlock];

// 设置返回对象的格式，YTKRequestSerializerTypeHTTP代表返回二进制格式，YTKRequestSerializerTypeJSON代表返回一个json的根对象（NSDictionary或者NSArray）

if (request.requestSerializerType == YTKRequestSerializerTypeHTTP) {

_manager.requestSerializer = [AFHTTPRequestSerializer serializer];

} else if (request.requestSerializerType == YTKRequestSerializerTypeJSON) {

_manager.requestSerializer = [AFJSONRequestSerializer serializer];

}

_manager.requestSerializer.timeoutInterval = [request requestTimeoutInterval];

// 如果请求需要授权证书，这里设置用户名和密码

NSArray *authorizationHeaderFieldArray = [request requestAuthorizationHeaderFieldArray];

if (authorizationHeaderFieldArray != nil) {

[_manager.requestSerializer setAuthorizationHeaderFieldWithUsername:(NSString *)authorizationHeaderFieldArray.firstObject

password:(NSString *)authorizationHeaderFieldArray.lastObject];

}

// 设置其他HTTP header

NSDictionary *headerFieldValueDictionary = [request requestHeaderFieldValueDictionary];

if (headerFieldValueDictionary != nil) {

for (id httpHeaderField in headerFieldValueDictionary.allKeys) {

id value = headerFieldValueDictionary[httpHeaderField];

if ([httpHeaderField isKindOfClass:[NSString class]] && [value isKindOfClass:[NSString class]]) {

[_manager.requestSerializer setValue:(NSString *)value forHTTPHeaderField:(NSString *)httpHeaderField];

} else {

YTKLog(@"Error, class of key/value in headerFieldValueDictionary should be NSString.");

}}}

// 如果创建了自定义的NSURLRequest对象，就使用自定的对象

NSURLRequest *customUrlRequest= [request buildCustomUrlRequest];

if (customUrlRequest) {

// 创建 AFHTTPRequestOperation 对象

AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:customUrlRequest];

[operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *op, id responseObject) {

// 处理结果

[self handleRequestResult:op];

} failure:^(AFHTTPRequestOperation *op, NSError *error) {

[self handleRequestResult:op];

}];

request.requestOperation = operation;

operation.responseSerializer = _manager.responseSerializer;

// 添加到请求队列

[_manager.operationQueue addOperation:operation];

} else {

// 没有自定义NSURLRequest，需要手动创建

if (method == YTKRequestMethodGet) {

// 如果需要断点续传下载文件

if (request.resumableDownloadPath) {

// 拼接参数到url

NSString *filteredUrl = [YTKNetworkPrivate urlStringWithOriginUrlString:url appendParameters:param];

NSURLRequest *requestUrl = [NSURLRequest requestWithURL:[NSURL URLWithString:filteredUrl]];

AFDownloadRequestOperation *operation = [[AFDownloadRequestOperation alloc] initWithRequest:requestUrl targetPath:request.resumableDownloadPath shouldResume:YES];

// 设置断点续传的进度回调block

[operation setProgressiveDownloadProgressBlock:request.resumableDownloadProgressBlock];

// 整个请求完成的回调block

[operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *op, id responseObject) {

[self handleRequestResult:op];

} failure:^(AFHTTPRequestOperation *op, NSError *error) {

[self handleRequestResult:op];

}];

request.requestOperation = operation;

[_manager.operationQueue addOperation:operation];

} else {

request.requestOperation = [_manager GET:url parameters:param success:^(AFHTTPRequestOperation *operation, id responseObject) {

[self handleRequestResult:operation];

} failure:^(AFHTTPRequestOperation *operation, NSError *error) {

[self handleRequestResult:operation];

}];

}

} else if (method == YTKRequestMethodPost) {

if (constructingBlock != nil) {

// constructingBlock是一个返回实现AFMultipartFormData协议的对象，该对象主要作用是实现文件上传

// 我们通常会上传图片或者文件需要用到multipart/form-data，实现以下即可：                /*                  - (AFConstructingBlock)constructingBodyBlock {                  return ^(idformData) {

NSData *data = UIImageJPEGRepresentation([UIImage imageNamed:@"currentPageDot"], 0.9);

NSString *name = @"image";

NSString *formKey = @"image";

NSString *type = @"image/jpeg";

[formData appendPartWithFileData:data name:formKey fileName:name mimeType:type];

};

}*/

request.requestOperation = [_manager POST:url parameters:param constructingBodyWithBlock:constructingBlock success:^(AFHTTPRequestOperation *operation, id responseObject) {

[self handleRequestResult:operation];

} failure:^(AFHTTPRequestOperation *operation, NSError *error) {

[self handleRequestResult:operation];

}];

} else {

request.requestOperation = [_manager POST:url parameters:param success:^(AFHTTPRequestOperation *operation, id responseObject) {

[self handleRequestResult:operation];

} failure:^(AFHTTPRequestOperation *operation, NSError *error) {

[self handleRequestResult:operation];

}];

}

} else if (method == YTKRequestMethodHead) {

// 只返回head的请求

request.requestOperation = [_manager HEAD:url parameters:param success:^(AFHTTPRequestOperation *operation) {

[self handleRequestResult:operation];

} failure:^(AFHTTPRequestOperation *operation, NSError *error) {

[self handleRequestResult:operation];

}];

} else if (method == YTKRequestMethodPut) {

// 更新资源的请求

request.requestOperation = [_manager PUT:url parameters:param success:^(AFHTTPRequestOperation *operation, id responseObject) {

[self handleRequestResult:operation];

} failure:^(AFHTTPRequestOperation *operation, NSError *error) {

[self handleRequestResult:operation];

}];

} else if (method == YTKRequestMethodDelete) {

// 删除资源

request.requestOperation = [_manager DELETE:url parameters:param success:^(AFHTTPRequestOperation *operation, id responseObject) {

[self handleRequestResult:operation];

} failure:^(AFHTTPRequestOperation *operation, NSError *error) {

[self handleRequestResult:operation];

}];

} else if (method == YTKRequestMethodPatch) {

// 对PUT请求的补充，更新部分资源

request.requestOperation = [_manager PATCH:url parameters:param success:^(AFHTTPRequestOperation *operation, id responseObject) {

[self handleRequestResult:operation];

} failure:^(AFHTTPRequestOperation *operation, NSError *error) {

[self handleRequestResult:operation];

}];

} else {

YTKLog(@"Error, unsupport method type");

return;}}

// 添加一个请求到_requestsRecord字典中，key是AFHTTPRequestOperation的hash值，value是YTKBaseRequest对象

// _requestsRecord的作用：当请求完成时，AFN返回operation，通过_requestsRecord可以反射出它所属的YTKBaseRequest对象

[self addOperation:request];

}

-(void)cancelRequest:(YTKBaseRequest *)request;

- (void)cancelRequest:(YTKBaseRequest *)request {

[request.requestOperation cancel];

[self removeOperation:request.requestOperation];

[request clearCompletionBlock];

}

-(void)cancelAllRequests;

- (void)cancelAllRequests {

NSDictionary *copyRecord = [_requestsRecord copy];

for (NSString *key in copyRecord) {

YTKBaseRequest *request = copyRecord[key];

[request stop];

}

}

-(NSString )buildRequestUrl:(YTKBaseRequest )request;

YTKBaseRequest

YTKRequest的父类，先介绍它几个重要的属性和方法。

需要子类来重写的方法

/// 请求成功的回调

-(void)requestCompleteFilter;

/// 请求失败的回调

-(void)requestFailedFilter;

/// 请求的URL

-(NSString *)requestUrl;

/// 请求的CdnURL

-(NSString *)cdnUrl;

/// 请求的BaseURL

(NSString *)baseUrl;

/// 请求的连接超时时间，默认为60秒

-(NSTimeInterval)requestTimeoutInterval;

/// 请求的参数列表

-(id)requestArgument;

/// 用于在cache结果，计算cache文件名时，忽略掉一些指定的参数

-(id)cacheFileNameFilterForRequestArgument:(id)argument;

/// Http请求的方法

-(YTKRequestMethod)requestMethod;

/// 请求的SerializerType

-(YTKRequestSerializerType)requestSerializerType;

/// 请求的Server用户名和密码

-(NSArray *)requestAuthorizationHeaderFieldArray;

/// 在HTTP报头添加的自定义参数    

  -(NSDictionary *)requestHeaderFieldValueDictionary;

    /// 构建自定义的UrlRequest，

  /// 若这个方法返回非nil对象，会忽略requestUrl, requestArgument, requestMethod, requestSerializerType        -(NSURLRequest *)buildCustomUrlRequest;  

/// 是否使用CDN的host地址        -(BOOL)useCDN;    /// 用于检查JSON是否合法的对象        -(id)jsonValidator;  

/// 用于检查Status Code是否正常的方法        -(BOOL)statusCodeValidator;    /// 当POST的内容带有文件等富文本时使用        -(AFConstructingBlock)constructingBodyBlock; 

  /// 当需要断点续传时，指定续传的地址        -(NSString*)resumableDownloadPath; 

  /// 当需要断点续传时，获得下载进度的回调        -(AFDownloadProgressBlock)resumableDownloadProgressBlock;里面重要的两个方法:- (void)start {   

// 调用即将开始请求的hook  

[self toggleAccessoriesWillStartCallBack];    [[YTKNetworkAgent sharedInstance] addRequest:self];}

/// remove self from request queue- (void)stop { 

  // 即将结束的hook 

  [self toggleAccessoriesWillStopCallBack];  

self.delegate = nil; 

  [[YTKNetworkAgent sharedInstance] cancelRequest:self];  

[self toggleAccessoriesDidStopCallBack];}

还有一个比较重要的增加hook的方法，需要自定义个对象，实现YTKRequestAccessory协议定义的一些方法来hook一些动作- (void)addAccessory:(id)accessory {

// 因为可能有多个hook对象，所以添加到一个数组中，调用的时候也是遍历数组调用

if (!self.requestAccessories) {

self.requestAccessories = [NSMutableArray array];

}

[self.requestAccessories addObject:accessory];

}

YTKRequest

这里主要实现了一些缓存策略，重写了父类的start方法

- (void)start {

if (self.ignoreCache) {

[super start];

return;

}

// 查看缓存时间是否过期

if ([self cacheTimeInSeconds] < 0) {

[super start];

return;

}

// 查看本地的缓存版本号和当前缓存判断是否匹配

long long cacheVersionFileContent = [self cacheVersionFileContent];

if (cacheVersionFileContent != [self cacheVersion]) {

[super start];

return;

}

// 查看缓存文件是否存在

NSString *path = [self cacheFilePath];

NSFileManager *fileManager = [NSFileManager defaultManager];

if (![fileManager fileExistsAtPath:path isDirectory:nil]) {

[super start];

return;

}

// 查看缓存时间是否过期

int seconds = [self cacheFileDuration:path];

if (seconds < 0 || seconds > [self cacheTimeInSeconds]) {

[super start];

return;

}

// 加载缓存数据

_cacheJson = [NSKeyedUnarchiver unarchiveObjectWithFile:path];

if (_cacheJson == nil) {

[super start];

return;

}

_dataFromCache = YES;

// 调用缓存结束回调

[self requestCompleteFilter];

YTKRequest *strongSelf = self;

[strongSelf.delegate requestFinished:strongSelf];

if (strongSelf.successCompletionBlock) {

strongSelf.successCompletionBlock(strongSelf);

}

[strongSelf clearCompletionBlock];

}

缓存是存放在本地文件中的，文件名用一些关键字的字符串拼接并md5来表示:

- (NSString *)cacheFileName {

NSString *requestUrl = [self requestUrl];

NSString *baseUrl = [YTKNetworkConfig sharedInstance].baseUrl;

id argument = [self cacheFileNameFilterForRequestArgument:[self requestArgument]];

NSString *requestInfo = [NSString stringWithFormat:@"Method:%ld Host:%@ Url:%@ Argument:%@ AppVersion:%@ Sensitive:%@", (long)[self requestMethod], baseUrl, requestUrl,

argument, [YTKNetworkPrivate appVersionString], [self cacheSensitiveData]];

NSString *cacheFileName = [YTKNetworkPrivate md5StringFromString:requestInfo];

return cacheFileName;

}

YTKNetworkConfig

这个类主要负责一些配置的工作，配置baseUrl，cdnUrl等工作，内部没有什么具体的实现，在其他类中获取这个类的配置信息

YTKBatchRequestAgent、YTKBatchRequest

用于方便地发送批量的网络请求，YTKBatchRequest是一个容器类，它可以放置多个 YTKRequest 子类，并统一处理这多个网络请求的成功和失败。

在如下的示例中，我们发送了4个批量的请求，并统一处理这4个请求同时成功的回调。

- (void)sendBatchRequest {

GetImageApi *a = [[GetImageApi alloc] initWithImageId:@"1.jpg"];

GetImageApi *b = [[GetImageApi alloc] initWithImageId:@"2.jpg"];

GetImageApi *c = [[GetImageApi alloc] initWithImageId:@"3.jpg"];

GetUserInfoApi *d = [[GetUserInfoApi alloc] initWithUserId:@"123"];

YTKBatchRequest *batchRequest = [[YTKBatchRequest alloc] initWithRequestArray:@[a, b, c, d]];

[batchRequest startWithCompletionBlockWithSuccess:^(YTKBatchRequest *batchRequest) {

NSLog(@"succeed");

NSArray *requests = batchRequest.requestArray;

GetImageApi *a = (GetImageApi *)requests[0];

GetImageApi *b = (GetImageApi *)requests[1];

GetImageApi *c = (GetImageApi *)requests[2];

GetUserInfoApi *user = (GetUserInfoApi *)requests[3];

// deal with requests result ...

} failure:^(YTKBatchRequest *batchRequest) {

NSLog(@"failed");

}];

}

内部实现，start方法遍历所有request，并调用start方法

- (void)start {

if (_finishedCount > 0) {

YTKLog(@"Error! Batch request has already started.");

return;

}

[[YTKBatchRequestAgent sharedInstance] addBatchRequest:self];

[self toggleAccessoriesWillStartCallBack];

for (YTKRequest * req in _requestArray) {

req.delegate = self;

[req start];

}

}

在成功回调中，有一个计数器，判断所有请求是否都已经完成

- (void)requestFinished:(YTKRequest *)request {

_finishedCount++;

if (_finishedCount == _requestArray.count) {

[self toggleAccessoriesWillStopCallBack];

if ([_delegate respondsToSelector:@selector(batchRequestFinished:)]) {

[_delegate batchRequestFinished:self];

}

if (_successCompletionBlock) {

_successCompletionBlock(self);

}

[self clearCompletionBlock];

[self toggleAccessoriesDidStopCallBack];

}

}

YTKChainRequestAgent、YTKChainRequest

用于管理有相互依赖的网络请求，它实际上最终可以用来管理多个拓扑排序后的网络请求。

以下是具体的代码示例，在示例中，我们在sendChainRequest方法中设置好了Api相互的依赖，然后。 我们就可以通过chainRequestFinished回调来处理所有网络请求都发送成功的逻辑了。如果有任何其中一个网络请求失败了，则会触发chainRequestFailed回调。

- (void)sendChainRequest {

RegisterApi *reg = [[RegisterApi alloc] initWithUsername:@"username" password:@"password"];

YTKChainRequest *chainReq = [[YTKChainRequest alloc] init];

[chainReq addRequest:reg callback:^(YTKChainRequest *chainRequest, YTKBaseRequest *baseRequest) {

RegisterApi *result = (RegisterApi *)baseRequest;

NSString *userId = [result userId];

GetUserInfoApi *api = [[GetUserInfoApi alloc] initWithUserId:userId];

[chainRequest addRequest:api callback:nil];

}];

chainReq.delegate = self;

// start to send request

[chainReq start];

}

- (void)chainRequestFinished:(YTKChainRequest *)chainRequest {

// all requests are done

}

- (void)chainRequestFailed:(YTKChainRequest *)chainRequest failedBaseRequest:(YTKBaseRequest*)request {

// some one of request is failed

}

内部实现，定义一个_nextRequestIndex，初始化为0，_requestArray请求数组，_requestCallbackArray请求回调数组

- (void)start {

if (_nextRequestIndex > 0) {

YTKLog(@"Error! Chain request has already started.");

return;

}

if ([_requestArray count] > 0) {

[self toggleAccessoriesWillStartCallBack];

[self startNextRequest];

[[YTKChainRequestAgent sharedInstance] addChainRequest:self];

} else {

YTKLog(@"Error! Chain request array is empty.");

}}

// 顺序执行请求，_nextRequestIndex++

- (BOOL)startNextRequest {

if (_nextRequestIndex < [_requestArray count]) {

YTKBaseRequest *request = _requestArray[_nextRequestIndex];

_nextRequestIndex++;

request.delegate = self;

[request start];

return YES;

} else {

return NO;}}

// 请求成功回调

- (void)requestFinished:(YTKBaseRequest *)request {

// 获取当前请求的回调，并调用其回调，回调中需要用户自己去再次去add一个新的request

NSUInteger currentRequestIndex = _nextRequestIndex - 1;

ChainCallback callback = _requestCallbackArray[currentRequestIndex];

callback(self, request);

// 当不能继续执行请求时，结束本次chain请求，调用完成回调

if (![self startNextRequest]) {

[self toggleAccessoriesWillStopCallBack];

if ([_delegate respondsToSelector:@selector(chainRequestFinished:)]) {

[_delegate chainRequestFinished:self];

[[YTKChainRequestAgent sharedInstance] removeChainRequest:self];

}

[self toggleAccessoriesDidStopCallBack];}}

YTKNetworkPrivate

定义一些内部使用的工具方法