说明：文件上传使用的时POST请求，通常把要上传的数据保存在请求体中。本文介绍如何不借助第三方框架实现iOS开发中得文件上传。

　　由于过程较为复杂，因此本文只贴出部分关键代码。

主控制器的关键代码：

YYViewController.m

1 #import "YYViewController.h"  2  3 #define YYEncode(str) [str dataUsingEncoding:NSUTF8StringEncoding] 4  5 @interface YYViewController () 6  7 @end  8  9 @implementation YYViewController10 11 - (void)viewDidLoad12 {13  [super viewDidLoad];14 // Do any additional setup after loading the view, typically from a nib. 15 }16 17 - (void)upload:(NSString *)name filename:(NSString *)filename mimeType:(NSString *)mimeType data:(NSData *)data parmas:(NSDictionary *)params 18 {19 // 文件上传 20 NSURL *url = [NSURL URLWithString:@"http://192.168.1.200:8080/YYServer/upload"];21 NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];22 request.HTTPMethod = @"POST";23 24 // 设置请求体 25 NSMutableData *body = [NSMutableData data];26 27 /***************文件参数***************/ 28 // 参数开始的标志 29 [body appendData:YYEncode(@"--YY\r\n")];30 // name : 指定参数名(必须跟服务器端保持一致)31 // filename : 文件名 32 NSString *disposition = [NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"; filename=\"%@\"\r\n", name, filename];33  [body appendData:YYEncode(disposition)];34 NSString *type = [NSString stringWithFormat:@"Content-Type: %@\r\n", mimeType];35  [body appendData:YYEncode(type)];36 37 [body appendData:YYEncode(@"\r\n")];38  [body appendData:data];39 [body appendData:YYEncode(@"\r\n")];40 41 /***************普通参数***************/ 42 [params enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {43 // 参数开始的标志 44 [body appendData:YYEncode(@"--YY\r\n")];45 NSString *disposition = [NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"\r\n", key];46  [body appendData:YYEncode(disposition)];47 48 [body appendData:YYEncode(@"\r\n")];49  [body appendData:YYEncode(obj)];50 [body appendData:YYEncode(@"\r\n")];51  }];52 53 /***************参数结束***************/ 54 // YY--\r\n 55 [body appendData:YYEncode(@"--YY--\r\n")];56 request.HTTPBody = body;57 58 // 设置请求头59 // 请求体的长度 60 [request setValue:[NSString stringWithFormat:@"%zd", body.length] forHTTPHeaderField:@"Content-Length"];61 // 声明这个POST请求是个文件上传 62 [request setValue:@"multipart/form-data; boundary=YY" forHTTPHeaderField:@"Content-Type"];63 64 // 发送请求 65 [NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {66 if (data) {67 NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableLeaves error:nil];68 NSLog(@"%@", dict);69 } else {70 NSLog(@"上传失败");71  }72  }];73 }74 75 - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event 76 {77 // Socket 实现断点上传78 79 //apache-tomcat-6.0.41/conf/web.xml 查找 文件的 mimeType80 // UIImage *image = [UIImage imageNamed:@"test"];81 // NSData *filedata = UIImagePNGRepresentation(image);82 // [self upload:@"file" filename:@"test.png" mimeType:@"image/png" data:filedata parmas:@{@"username" : @"123"}];83 84 // 给本地文件发送一个请求 85 NSURL *fileurl = [[NSBundle mainBundle] URLForResource:@"itcast.txt" withExtension:nil];86 NSURLRequest *request = [NSURLRequest requestWithURL:fileurl];87 NSURLResponse *repsonse = nil;88 NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:&repsonse error:nil];89 90 // 得到mimeType 91 NSLog(@"%@", repsonse.MIMEType);92 [self upload:@"file" filename:@"itcast.txt" mimeType:repsonse.MIMEType data:data parmas:@{93 @"username" : @"999",94 @"type" : @"XML"}];95 }96 97 @end

补充说明：

文件上传请求数据格式

部分文件的MIMEType