iOS开发网络篇—文件的上传

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 YYViewController
10 
11 - (void)viewDidLoad
12 {
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
")];
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="%@"
", name, filename];
33     [body appendData:YYEncode(disposition)];
34     NSString *type = [NSString stringWithFormat:@"Content-Type: %@
", mimeType];
35     [body appendData:YYEncode(type)];
36     
37     [body appendData:YYEncode(@"
")];
38     [body appendData:data];
39     [body appendData:YYEncode(@"
")];
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
")];
45         NSString *disposition = [NSString stringWithFormat:@"Content-Disposition: form-data; name="%@"
", key];
46         [body appendData:YYEncode(disposition)];
47 
48         [body appendData:YYEncode(@"
")];
49         [body appendData:YYEncode(obj)];
50         [body appendData:YYEncode(@"
")];
51     }];
52     
53     /***************参数结束***************/
54     // YY--

55     [body appendData:YYEncode(@"--YY--
")];
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 mimeType
80 //    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