[iOS 多线程 & 网络

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

    [body appendData:UTF8Encode(@"--HelloVoidWorldBoundary--
")];
    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