NSURLSession 学习笔记
一：NSURLSession
- 类似之前的NSURLConnection, 可配置每个session的 cookie,证书等网络连接配置信息
NSURLSessionConfiguration
- 包含三大任务
：NSURLSessionTask--(NSURLSessionDataTask,NSURLSessionUploadTask,NSURLSessionDownloadTask) - 常用api
@interface NSURLSession : NSObject// 单例
+ (NSURLSession *)sharedSession;//配置 Session
+ (NSURLSession *)sessionWithConfiguration:(NSURLSessionConfiguration *)configuration;
+ (NSURLSession *)sessionWithConfiguration:(NSURLSessionConfiguration *)configuration delegate:(id <NSURLSessionDelegate>)delegate delegateQueue:(NSOperationQueue *)queue;
/*Data 请求 request */
- (NSURLSessionDataTask *)dataTaskWithRequest:(NSURLRequest *)request;/* Data 请求 url. */
- (NSURLSessionDataTask *)dataTaskWithURL:(NSURL *)url;/* 上传文件请求 fileUrl */
- (NSURLSessionUploadTask *)uploadTaskWithRequest:(NSURLRequest *)request fromFile:(NSURL *)fileURL;/* 上传Data请求 NSData */
- (NSURLSessionUploadTask *)uploadTaskWithRequest:(NSURLRequest *)request fromData:(NSData *)bodyData;/* 上传数据流请求 request */
- (NSURLSessionUploadTask *)uploadTaskWithStreamedRequest:(NSURLRequest *)request;/* 下载文件.request */
- (NSURLSessionDownloadTask *)downloadTaskWithRequest:(NSURLRequest *)request;/* 下载文件 url */
- (NSURLSessionDownloadTask *)downloadTaskWithURL:(NSURL *)url;/* 断点下载请求 ， */
- (NSURLSessionDownloadTask *)downloadTaskWithResumeData:(NSData *)resumeData;
异步请求操作
@interface NSURLSession (NSURLSessionAsynchronousConvenience)
/* 异步数据请求 NSData */
- (NSURLSessionDataTask *)dataTaskWithRequest:(NSURLRequest *)request completionHandler:(void (^)(NSData *data, NSURLResponse *response, NSError *error))completionHandler;
- (NSURLSessionDataTask *)dataTaskWithURL:(NSURL *)url completionHandler:(void (^)(NSData *data, NSURLResponse *response, NSError *error))completionHandler;/*
* 异步文件上传请求 file,NSData
*/
- (NSURLSessionUploadTask *)uploadTaskWithRequest:(NSURLRequest *)request fromFile:(NSURL *)fileURL completionHandler:(void (^)(NSData *data, NSURLResponse *response, NSError *error))completionHandler;
- (NSURLSessionUploadTask *)uploadTaskWithRequest:(NSURLRequest *)request fromData:(NSData *)bodyData completionHandler:(void (^)(NSData *data, NSURLResponse *response, NSError *error))completionHandler;/* 异步下载请求 */
- (NSURLSessionDownloadTask *)downloadTaskWithRequest:(NSURLRequest *)request completionHandler:(void (^)(NSURL *location, NSURLResponse *response, NSError *error))completionHandler;
- (NSURLSessionDownloadTask *)downloadTaskWithURL:(NSURL *)url completionHandler:(void (^)(NSURL *location, NSURLResponse *response, NSError *error))completionHandler;
- (NSURLSessionDownloadTask *)downloadTaskWithResumeData:(NSData *)resumeData completionHandler:(void (^)(NSURL *location, NSURLResponse *response, NSError *error))completionHandler;@end
二：NSURLSessionTask 任务
- 包含三大任务
：NSURLSessionTask--(NSURLSessionDataTask,NSURLSessionUploadTask,NSURLSessionDownloadTask) - 关系图
系统定义的 常用api，如，对 网络任务的暂停，继续
@interface NSURLSessionTask : NSObject <NSCopying>........
/* 取消任务*/
- (void)cancel;/* 任务状态*/
@property (readonly) NSURLSessionTaskState state;/*任务暂停和继续 */
- (void)suspend;
- (void)resume;
........
@end
任务状态：
typedef NS_ENUM(NSInteger, NSURLSessionTaskState) {
NSURLSessionTaskStateRunning = 0, /* The task is currently being serviced by the session */
NSURLSessionTaskStateSuspended = 1,
NSURLSessionTaskStateCanceling = 2, /* The task has been told to cancel. The session will receive a URLSession:task:didCompleteWithError: message. */
NSURLSessionTaskStateCompleted = 3, /* The task has completed and the session will receive no more delegate notifications */
} NS_ENUM_AVAILABLE(10_9, 7_0);
三大子类，Data,Upload，Download操作 ，都是抽象类，基本不提供任何操作
@interface NSURLSessionDataTask : NSURLSessionTask
@end/*
* An NSURLSessionUploadTask does not currently provide any additional*/@interface NSURLSessionUploadTask : NSURLSessionDataTask
@end@interface NSURLSessionDownloadTask : NSURLSessionTask
/*断点续传 */
- (void)cancelByProducingResumeData:(void (^)(NSData *resumeData))completionHandler;@end
三：演示代码
1:异步的GET 请求 Data 数据
NSURL *url = [NSURL URLWithString:@"http://httpbin.org/get"];
NSURLSession *session = [NSURLSession sharedSession];
NSURLSessionDataTask *dataTask = [session dataTaskWithURL:url completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {NSLog(@"%@",[[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding]);
}];
//任务创建后，不会立即执行，调用resume 立即执行;
[dataTask resume];
2：异步 下载文件
NSURL *url = [NSURL URLWithString:@"http://dl.360safe.com/360zip_setup_3.1.0.2061.exe"];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
NSURLSession *session = [NSURLSession sharedSession];
NSURLSessionDownloadTask *downTask = [session downloadTaskWithRequest:request completionHandler:^(NSURL *location, NSURLResponse *response, NSError *error) {//文件下载会被先写入到一个 临时路径 location,我们需要将下载的文件移动到我们需要地方保存
NSURL *savePath = [NSURL fileURLWithPath:@"/Users/user/Desktop/360zip.exe"];
[[NSFileManager defaultManager] moveItemAtURL:location toURL:savePath error:nil];}];
[downTask resume];
3: 异步上传文件
NSURL *URL = [NSURL URLWithString:@"http://example.com/upload"];
NSURLRequest *request = [NSURLRequest requestWithURL:URL];
NSData *data = ...;NSURLSession *session = [NSURLSession sharedSession];
NSURLSessionUploadTask *uploadTask = [session uploadTaskWithRequest:request
fromData:data
completionHandler:
^(NSData *data, NSURLResponse *response, NSError *error) {
// ...
}];[uploadTask resume];
参考：http://objccn.io/issue-5-4/