[iOS 多线程 & 网络 - 2.5] - 小文件上传

A.文件上传

思路：

发送文件数据给服务器

使用post请求

必须手动设置请求头: 内容大小Content-Length & 内容类型 Content-Type

请求体：文件数据

文件上传的格式要求十分严格，必须严格遵守

由于是一次性加载文件到内存上传，所以只能用于小文件上传

 

B.实现

1.设置POST请求

（1）使用POST请求方法

（2）设置请求头

设置内容长度、内容类型、分割线

 

（3）设置请求体

NSMutableData *body = [NSMutableData data];

分割线 + 换行

内容描述 + 换行

内容类型 + 换行

换行

文件二进制数据 + 换行

分割线--

 

 

multipart/form-data 中的内容

 

 

例如使用chrome上传一张图片：

 

（4）使用本地请求获取某种文件类型的MIMEType

 /** 取得本地文件的MIMEType */
 - (void) getMIMEType {
     // Socket 实现断点上传

     //apache-tomcat-6.0.41/conf/web.xml 查找 文件的 mimeType
     //    UIImage *image = [UIImage imageNamed:@"test"];
     //    NSData *filedata = UIImagePNGRepresentation(image);
     //    [self upload:@"file" filename:@"test.png" mimeType:@"image/png" data:filedata parmas:@{@"username" : @"123"}];

     // 给本地文件发送一个请求
     NSURL *fileurl = [[NSBundle mainBundle] URLForResource:@"itcast.txt" withExtension:nil];
     NSURLRequest *request = [NSURLRequest requestWithURL:fileurl];
     NSURLResponse *repsonse = nil;
     NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:&repsonse error:nil];

     // 得到mimeType
     NSLog(@"%@", repsonse.MIMEType);
     [self upload:@"file" filename:@"itcast.txt" mimeType:repsonse.MIMEType data:data parmas:@{@"username":@"tom", @"type":@"xml"}];
 }

 

 

附：常见文件类型的MIMEType

 

 //
 //  ViewController.m
 //  UploadFileDemo
 //
 //  Created by hellovoidworld on 15/1/28.
 //  Copyright (c) 2015年 hellovoidworld. All rights reserved.
 //

 #import "ViewController.h"

 #define UTF8Encode(str) [str dataUsingEncoding:NSUTF8StringEncoding]

 @interface ViewController ()

 - (IBAction)upload;

 @end

 @implementation ViewController

 - (void)viewDidLoad {
     [super viewDidLoad];
     // Do any additional setup after loading the view, typically from a nib.
 }

 - (void)didReceiveMemoryWarning {
     [super didReceiveMemoryWarning];
     // Dispose of any resources that can be recreated.
 }

 - (IBAction)upload {
     UIImage *image = [UIImage imageNamed:@"IMG_0413"];
     NSData *imageData = UIImagePNGRepresentation(image);
     [self upload:@"uploadedFile" filename:@"IMG_0413.PNG" mimeType:@"image/png" data:imageData parmas:nil];
 }

 - (void)upload:(NSString *)name filename:(NSString *)filename mimeType:(NSString *)mimeType data:(NSData *)data parmas:(NSDictionary *)params
 {
     // 文件上传
     NSURL *url = [NSURL URLWithString:@"http://192.168.0.21:8080/MyTestServer/upload"];
     NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
     request.HTTPMethod = @"POST";

     // 设置请求体
     NSMutableData *body = [NSMutableData data];

     /***************文件参数***************/
     // 参数开始的标志
     [body appendData:UTF8Encode(@"--HelloVoidWorldBoundary\r\n")];
     // name : 指定参数名(必须跟服务器端保持一致)
     // filename : 文件名
     NSString *disposition = [NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"; filename=\"%@\"\r\n", name, filename];
     [body appendData:UTF8Encode(disposition)];
     NSString *type = [NSString stringWithFormat:@"Content-Type: %@\r\n", mimeType];
     [body appendData:UTF8Encode(type)];

     [body appendData:UTF8Encode(@"\r\n")];
     [body appendData:data];
     [body appendData:UTF8Encode(@"\r\n")];

     /***************普通参数***************/
     [params enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
         // 参数开始的标志
         [body appendData:UTF8Encode(@"--HelloVoidWorldBoundary\r\n")];
         NSString *disposition = [NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"\r\n", key];
         [body appendData:UTF8Encode(disposition)];

         [body appendData:UTF8Encode(@"\r\n")];
         [body appendData:UTF8Encode(obj)];
         [body appendData:UTF8Encode(@"\r\n")];
     }];

     /***************参数结束***************/
     // HelloVoidWorldBoundary--\r\n
     [body appendData:UTF8Encode(@"--HelloVoidWorldBoundary--\r\n")];
     request.HTTPBody = body;

     // 设置请求头
     // 请求体的长度
     [request setValue:[NSString stringWithFormat:@"%zd", body.length] forHTTPHeaderField:@"Content-Length"];
     // 声明这个POST请求是个文件上传
     [request setValue:@"multipart/form-data; boundary=HelloVoidWorldBoundary" forHTTPHeaderField:@"Content-Type"];

     // 发送请求
     [NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
         NSLog(@"开始上传~~~");
         if (data) {
             NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableLeaves error:nil];
             NSLog(@"%@", dict);
         } else {
             NSLog(@"上传失败");
         }
     }];
 }

 /** 取得本地文件的MIMEType */
 - (void) getMIMEType {
     // Socket 实现断点上传

     //apache-tomcat-6.0.41/conf/web.xml 查找 文件的 mimeType
     //    UIImage *image = [UIImage imageNamed:@"test"];
     //    NSData *filedata = UIImagePNGRepresentation(image);
     //    [self upload:@"file" filename:@"test.png" mimeType:@"image/png" data:filedata parmas:@{@"username" : @"123"}];

     // 给本地文件发送一个请求
     NSURL *fileurl = [[NSBundle mainBundle] URLForResource:@"itcast.txt" withExtension:nil];
     NSURLRequest *request = [NSURLRequest requestWithURL:fileurl];
     NSURLResponse *repsonse = nil;
     NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:&repsonse error:nil];

     // 得到mimeType
     NSLog(@"%@", repsonse.MIMEType);
     [self upload:@"file" filename:@"itcast.txt" mimeType:repsonse.MIMEType data:data parmas:@{@"username":@"tom", @"type":@"xml"}];
 }

 @end