NSURLSession上传小文件

#import "ViewController.h"

#define     ZYXBoundary         @"520it"
#define     ZYXEncode(string)   [string dataUsingEncoding:NSUTF8StringEncoding]
#define     ZYXNewLine          [@"\r\n" dataUsingEncoding:NSUTF8StringEncoding]

@interface ViewController () 
/** session */
@property (nonatomic, strong) NSURLSession *session;
@end

@implementation ViewController

- (NSURLSession *)session{
    if (!_session) {
        NSURLSessionConfiguration *cfg = [NSURLSessionConfiguration defaultSessionConfiguration];
        cfg.timeoutIntervalForRequest = 10;
        // 是否允许使用蜂窝网络（手机自带网络）
        cfg.allowsCellularAccess = YES;
        _session = [NSURLSession sessionWithConfiguration:cfg];
    }
    return _session;
}

- (void)uploadFile{
    NSString *urlString = @"http://www.example.com:8080/upload";
    NSURL *url = [NSURL URLWithString:urlString];
    NSMutableURLRequest *requestM = [NSMutableURLRequest requestWithURL:url];
    requestM.HTTPMethod = @"POST";
    
    // 设置请求头(告诉服务器,这是一个文件上传的请求)
    [requestM setValue:[NSString stringWithFormat:@"multipart/form-data; boundary=%@", ZYXBoundary] forHTTPHeaderField:@"Content-Type"];
    
    // 设置请求体
    NSMutableData *body = [NSMutableData data];
    
    // 文件参数
    // 分割线
    [body appendData:ZYXEncode(@"--")];
    [body appendData:ZYXEncode(ZYXBoundary)];
    [body appendData:ZYXNewLine];
    
    // 文件参数名
    [body appendData:ZYXEncode([NSString stringWithFormat:@"Content-Disposition: form-data; name=\"file\"; filename=\"test.png\""])];
    [body appendData:ZYXNewLine];
    
    // 文件的类型
    [body appendData:ZYXEncode([NSString stringWithFormat:@"Content-Type: image/png"])];
    [body appendData:ZYXNewLine];
    
    // 文件数据
    [body appendData:ZYXNewLine];
    [body appendData:[NSData dataWithContentsOfFile:@"/Users/zhaoyingxin/Desktop/test.png"]];
    [body appendData:ZYXNewLine];
    
    // 结束标记
    /*
     --分割线--\r\n
     */
    [body appendData:ZYXEncode(@"--")];
    [body appendData:ZYXEncode(ZYXBoundary)];
    [body appendData:ZYXEncode(@"--")];
    [body appendData:ZYXNewLine];
    
    [[self.session uploadTaskWithRequest:requestM
                                fromData:body
                       completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
                           NSLog(@"%@", [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:nil]);
                       }]
     resume];
}

//{success : 上传成功}
//{error : 上传失败}