python - 当我将图像从 Swift 应用上传到服务器时出现错误

Question

当我将图像从 Swift 应用上传到 Django 服务器时出现错误，但我无法理解该错误的含义。回溯是

objc[31747]: Class PLBuildVersion is implemented in both /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator.sdk/System/Library/PrivateFrameworks/AssetsLibraryServices.framework/AssetsLibraryServices (0x11aa7d998) and /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator.sdk/System/Library/PrivateFrameworks/PhotoLibraryServices.framework/PhotoLibraryServices (0x119968880). One of the two will be used. Which one is undefined.
2017-06-16 23:11:52.837756 Kenshin_Swift[31747:1350088] [Generic] Creating an image format with an unknown type is an error
2017-06-16 23:11:54.274757 Kenshin_Swift[31747:1350153] [] nw_socket_get_input_frames recvmsg(fd 13, 1024 bytes): [54] Connection reset by peer
2017-06-16 23:11:54.276896 Kenshin_Swift[31747:1350153] [] nw_endpoint_flow_prepare_output_frames [1 127.0.0.1:8000 ready socket-flow (satisfied)] Failed to use 1 frames, marking as failed
2017-06-16 23:11:54.277301 Kenshin_Swift[31747:1350153] [] nw_socket_write_close shutdown(13, SHUT_WR): [57] Socket is not connected
2017-06-16 23:11:54.277684 Kenshin_Swift[31747:1350153] [] nw_endpoint_flow_service_writes [1 127.0.0.1:8000 ready socket-flow (satisfied)] Write request has 0 frame count, 0 byte count
2017-06-16 23:11:54.278467 Kenshin_Swift[31747:1350154] [] __tcp_connection_write_eof_block_invoke Write close callback received error: [89] Operation canceled
error=Optional(Error Domain=NSURLErrorDomain Code=-1001 "The request timed out." UserInfo={NSUnderlyingError=0x60800025cda0 {Error Domain=kCFErrorDomainCFNetwork Code=-1001 "(null)" UserInfo={_kCFStreamErrorCodeKey=-2102, _kCFStreamErrorDomainKey=4}}, NSErrorFailingURLStringKey=http://127.0.0.1:8000/accounts/upload_save/, NSErrorFailingURLKey=http://127.0.0.1:8000/accounts/upload_save/, _kCFStreamErrorDomainKey=4, _kCFStreamErrorCodeKey=-2102, NSLocalizedDescription=The request timed out.})

我在Swift中写了正确的url，用于上传图像，并且可以通过运行服务器来访问该url python manage.py runserver 0.0.0.0:8000，并且我运行我的服务器能够从其他设备访问，这意味着 Xcode 中的模拟器(这不是我的 iPhone 模拟器)所以，我不知道这个错误的含义，我应该怎么解决？Swift 代码是

func myImageUploadRequest()
    {

        let myUrl = NSURL(string: "http://127.0.0.1:8000/accounts/upload_save/");
        //let myUrl = NSURL(string: "http://www.boredwear.com/utils/postImage.php");

        let request = NSMutableURLRequest(url:myUrl! as URL);
        request.httpMethod = "POST";
        //ユーザーごとに割り振りたい
        let param = [
            "firstName"  : "Sergey",
            "lastName"    : "Kargopolov",
            "userId"    : "9"
        ]

        let boundary = generateBoundaryString()

        request.setValue("multipart/form-data; boundary=\(boundary)", forHTTPHeaderField: "Content-Type")

        guard let myImage = myImageView.image else {
            return
        }

        let imageData = UIImageJPEGRepresentation(myImageView.image!, 1)

        if(imageData==nil)  { return; }

        request.httpBody = createBodyWithParameters(parameters: param, filePathKey: "file", imageDataKey: imageData! as NSData, boundary: boundary) as Data


        myActivityIndicator.startAnimating();

        let task = URLSession.shared.dataTask(with: request as URLRequest) {
            data, response, error in

            if error != nil {
                print("error=\(error)")
                return
            }

            // You can print out response object
            print("******* response = \(response)")

            // Print out reponse body
            let responseString = NSString(data: data!, encoding: String.Encoding.utf8.rawValue)
            print("****** response data = \(responseString!)")

            do {
                let json = try JSONSerialization.jsonObject(with: data!, options: []) as? NSDictionary


                DispatchQueue.main.async {
                    self.myActivityIndicator.stopAnimating()
                    self.myImageView.image = nil;
                }

            }catch
            {
                print(error)
            }

        }

        task.resume()
    }


    func createBodyWithParameters(parameters: [String: String]?, filePathKey: String?, imageDataKey: NSData, boundary: String) -> NSData {
        let body = NSMutableData();

        if parameters != nil {
            for (key, value) in parameters! {
                body.appendString(string: "--\(boundary)\r\n")
                body.appendString(string: "Content-Disposition: form-data; name=\"\(key)\"\r\n\r\n")
                body.appendString(string: "\(value)\r\n")
            }
        }

        let filename = "user-profile.jpg"
        let mimetype = "image/jpg"

        body.appendString(string: "--\(boundary)\r\n")
        body.appendString(string: "Content-Disposition: form-data; name=\"\(filePathKey!)\"; filename=\"\(filename)\"\r\n")
        body.appendString(string: "Content-Type: \(mimetype)\r\n\r\n")
        body.append(imageDataKey as Data)
        body.appendString(string: "\r\n")



        body.appendString(string: "--\(boundary)--\r\n")

        return body
    }

    func generateBoundaryString() -> String {
        return "Boundary-\(NSUUID().uuidString)"
    }    
}
extension NSMutableData {
    func appendString(string: String) {
        let data = string.data(using: String.Encoding.utf8, allowLossyConversion: true)
        append(data!)
    }

此外，我的 Django 服务器代码是

from django.contrib.auth.forms import AuthenticationForm
from django.contrib.auth.decorators import login_required
from django.http import HttpResponse
from django.shortcuts import render, redirect
from django.views.decorators.http import require_POST
from .forms import RegisterForm
from django.contrib.auth import authenticate, login
from .models import Post
from .forms import UserImageForm
from .models import ImageAndUser

def index(request):
    context = {
        'user': request.user,
    }
    return render(request, 'registration/accounts/index.html', context)


@login_required
def profile(request):
    context = {
        'user': request.user,
    }
    return render(request, 'registration/accounts/profile.html', context)


def regist(request):
    form = RegisterForm(request.POST or None)
    context = {
        'form': form,
    }
    return render(request, 'registration/accounts/regist.html', context)

def index(request):
    context = {
        'user': request.user,
    }
    return render(request, 'registration/accounts/index.html', context)


@login_required
def profile(request):
    context = {
        'user': request.user,
    }
    return render(request, 'registration/accounts/profile.html', context)


def regist(request):
    form = RegisterForm(request.POST or None)
    context = {
        'form': form,
    }
    return render(request, 'registration/accounts/regist.html', context)


@require_POST
def regist_save(request):
    form = RegisterForm(request.POST)
    if form.is_valid():
        user = form.save()
        login(request, user)
        context = {
            'user': request.user,
        }
        return redirect('profile')


    context = {
        'form': form,
    }
    return render(request, 'registration/accounts/regist.html', context)

@login_required
def photo(request):
    d = {
        'photos': Post.objects.all(),
    }
    return render(request, 'registration/accounts/profile.html', d)


def upload(request, p_id):
    form = UserImageForm(request.POST or None)
    d = {
        'p_id': p_id,
        'form':form,
    }
    return render(request, 'registration/accounts/photo.html', d)


def upload_save(request):

    photo_id = request.POST.get("p_id", "")

    if (photo_id):
        photo_obj = Post.objects.get(id=photo_id)
    else:
        photo_obj = Post()

    files = request.FILES.getlist("files[]")


    photo_obj.image = files[0]
    # photo_obj.image2 = files[1]
    # photo_obj.image3 = files[2]

    photo_obj.save()
    # return render(request, "registration/accounts/photo.html")

    photos = Post.objects.all()
    context = {
        'photos': photos,
    }
    return render(request, 'registration/accounts/photo.html', context)

def kenshinresults(request):
    d = {
        'results': results,
    }
    return render(request, 'registration/accounts/kenshin_result.html', d)

def tc(request):
    tcresults = ImageAndUser.objects.filter(user=request.user).order_by('id').last()
    d = {
        'tcresults': tcresults,
    }
    return render(request, 'registration/accounts/tc.html', d)

Answer 1

错误很简单，Swift无法访问IP:端口127.0.0.1。

解决这个问题:

1. 检查是否有其他服务器正在监听 127.0.0.1:8000
2. 转到http://127.0.0.1:8000使用普通浏览器输入地址并检查 Django 是否正在应答
3. 转到http://127.0.0.1:8000使用您的 iPhone 浏览器确认地址

可能 127.0.0.1 并不代表您的 iPhone 模拟器的 django，请尝试使用您的外部 IP。