Core Foundation中NSURLConnection在2003年伴随着Safari浏览器的发行,诞生的时间比较久远,iOS升级比较快,AFNetWorking在3.0版本删除了所有基于NSURLConnection API的所有支持,新的API完全基于NSURLSession。AFNetworking 1.0建立在NSURLConnection的基础之上 ,AFNetworking 2.0使用NSURLConnection基础API,以及较新基于NSURLSession的API的选项。NSURLSession用于请求数据,作为URL加载系统,支持http,https,ftp,file,data协议。
基础知识
URL加载系统中需要用到的基础类:
iOS7和Mac OS X 10.9之后通过NSURLSession加载数据,调用起来也很方便:
NSURL *url=[NSURL URLWithString:@"http://www.cnblogs.com/xiaofeixiang"];
NSURLRequest *urlRequest=[NSURLRequest requestWithURL:url];
NSURLSession *urlSession=[NSURLSession sharedSession];
NSURLSessionDataTask *dataTask=[urlSession dataTaskWithRequest:urlRequest completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
NSDictionary *content = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:nil];
NSLog(@"%@",content);
}];
[dataTask resume];
NSURLSessionTask是一个抽象子类,它有三个具体的子类是可以直接使用的:NSURLSessionDataTask,NSURLSessionUploadTask和NSURLSessionDownloadTask。这三个类封装了现代应用程序的三个基本网络任务:获取数据,比如JSON或XML,以及上传下载文件。dataTaskWithRequest方法用的比较多,关于下载文件代码完成之后会保存一个下载之后的临时路径:
NSURLSessionDownloadTask *downloadTask=[urlSession downloadTaskWithRequest:urlRequest completionHandler:^(NSURL * _Nullable location, NSURLResponse * _Nullable response, NSError * _Nullable error) { }];
NSURLSessionUploadTask上传一个本地URL的NSData数据:
NSURLSessionUploadTask *uploadTask=[urlSession uploadTaskWithRequest:urlRequest fromData:[NSData new] completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) { }];
NSURLSession在Foundation中我们默认使用的block进行异步的进行任务处理,当然我们也可以通过delegate的方式在委托方法中异步处理任务,关于委托常用的两种NSURLSessionTaskDelegate和NSURLSessionDownloadDelegate,其他的关于NSURLSession的委托有兴趣的可以看一下API文档,首先我们需要设置delegate:
NSURLSessionConfiguration *sessionConfig = [NSURLSessionConfiguration defaultSessionConfiguration];
NSURLSession *inProcessSession = [NSURLSession sessionWithConfiguration:sessionConfig delegate:self delegateQueue:nil];
NSString *url = @"http://www.cnblogs.com/xiaofeixiang";
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:url]];
NSURLSessionTask *dataTask = [inProcessSession dataTaskWithRequest:request];
[dataTask resume];
任务下载的设置delegate:
NSURLSessionConfiguration *sessionConfig = [NSURLSessionConfiguration defaultSessionConfiguration];
NSURLSession *inProcessSession = [NSURLSession sessionWithConfiguration:sessionConfig delegate:self delegateQueue:nil];
NSString *url = @"http://www.cnblogs.com/xiaofeixiang";
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:url]];
NSURLSessionDownloadTask *downloadTask = [inProcessSession downloadTaskWithRequest:request];
[downloadTask resume];
关于delegate中的方式只实现其中的两种作为参考:
#pragma mark - NSURLSessionDownloadDelegate
-(void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didFinishDownloadingToURL:(NSURL *)location{
NSLog(@"NSURLSessionTaskDelegate--下载完成");
} #pragma mark - NSURLSessionTaskDelegate
-(void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didCompleteWithError:(NSError *)error{
NSLog(@"NSURLSessionTaskDelegate--任务结束");
}
NSURLSession状态同时对应着多个连接,不能使用共享的一个全局状态,会话是通过工厂方法来创建配置对象。
defaultSessionConfiguration(默认的,进程内会话),ephemeralSessionConfiguration(短暂的,进程内会话),backgroundSessionConfigurationWithIdentifier(后台会话)
第三种设置为后台会话的,当任务完成之后会调用application中的方法:
-(void)application:(UIApplication *)application handleEventsForBackgroundURLSession:(NSString *)identifier completionHandler:(void (^)())completionHandler{ }
网络封装
上面的基础知识能满足正常的开发,我们可以对常见的数据get请求,Url编码处理,动态添加参数进行封装,其中关于url中文字符串的处理
stringByAddingPercentEncodingWithAllowedCharacters属于新的方式,字符允许集合选择的是URLQueryAllowedCharacterSet,
NSCharacterSet中分类有很多,详细的可以根据需求进行过滤~
typedef void (^CompletioBlock)(NSDictionary *dict, NSURLResponse *response, NSError *error); @interface FENetWork : NSObject +(void)requesetWithUrl:(NSString *)url completeBlock:(CompletioBlock)block; +(void)requesetWithUrl:(NSString *)url params:(NSDictionary *)params completeBlock:(CompletioBlock)block; @end
@implementation FENetWork +(void)requesetWithUrl:(NSString *)url completeBlock:(CompletioBlock)block{
NSString *urlEnCode=[url stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLQueryAllowedCharacterSet]];
NSURLRequest *urlRequest=[NSURLRequest requestWithURL:[NSURL URLWithString:urlEnCode]];
NSURLSession *urlSession=[NSURLSession sharedSession];
NSURLSessionDataTask *dataTask=[urlSession dataTaskWithRequest:urlRequest completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
if (error) {
NSLog(@"%@",error);
block(nil,response,error);
}else{
NSDictionary *content = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:nil];
block(content,response,error);
}
}];
[dataTask resume];
} +(void)requesetWithUrl:(NSString *)url params:(NSDictionary *)params completeBlock:(CompletioBlock)block{ NSMutableString *mutableUrl=[[NSMutableString alloc]initWithString:url];
if ([params allKeys]) {
[mutableUrl appendString:@"?"];
for (id key in params) {
NSString *value=[[params objectForKey:key] stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLQueryAllowedCharacterSet]];
[mutableUrl appendString:[NSString stringWithFormat:@"%@=%@&",key,value]];
}
}
[self requesetWithUrl:[mutableUrl substringToIndex:mutableUrl.length-1] completeBlock:block];
} @end
参考资料:https://developer.apple.com/library/prerelease/mac/documentation/Cocoa/Reference/Foundation/Classes/NSCharacterSet_Class/index.html#//apple_ref/occ/clm/NSCharacterSet/URLQueryAllowedCharacterSet
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