使用 Alamofire url 响应错误下载 pdf 文件

Question

我想下载我使用此代码的 Pdf 文件 url：

class func downloadPdf(pdfReport: String, completion: @escaping (_ error: Error?, _ success: Bool,_ value: String) -> Void) {

    let downloadUrl: String = URLs.pdfFileUrl + pdfReport
    let destination = DownloadRequest.suggestedDownloadDestination()

    print(downloadUrl, destination)
    Alamofire.download(downloadUrl, method: .get, parameters: nil, encoding: JSONEncoding.default, to: destination).responseJSON { response in

        switch response.result {
        case .failure(let error):
            print("error: ", error)
            print(error.localizedDescription)
            completion(error, false, "")
        case .success(let value):
            let json = JSON(value)
            print(json)
            print("successss")
            completion(nil, true, "")
        }
    }
}

并在视图控制器中：

func downloadPdf() {
    KRProgressHUD.show(withMessage: NSLocalizedString("wait", comment: "wait"))
    API.downloadPdf(pdfReport: self.report.report){ (error: Error?, success: Bool, result: String) in
        if success {
            KRProgressHUD.dismiss()
        } else {
            KRProgressHUD.dismiss()
            if (!Connectivity.isConnectedToNetwork()){
                Toast.toast(messsage: NSLocalizedString("no internet", comment: "no internet"), view: self.view)
            } else {
                Toast.toast(messsage: NSLocalizedString("error occured", comment: "error occured"), view: self.view)
            }
        }
    }
}

当我downloadPdf第一次调用方法时，它成功下载了文件，但出现此错误：

https://madrasty.dev.ibtdi.work/public/reports/15287105135b1e4571f2596-new.pdf（函数）错误：responseSerializationFailed(Alamofire.AFError.ResponseSerializationFailureReason.jsonSerializationFailed(Error Domain=NSCocoaErrorDomain Code=384 around character) " UserInfo={NSDebugDescription=字符 0 周围的值无效。})) 由于错误，JSON 无法序列化：????? ????? ????????? ????? ？？？??????? ？？？????.

如果再次调用该方法，我会收到此错误：

错误：错误域=NSCocoaErrorDomain 代码=516 “?????? ??? “CFNetworkDownload_WBV95z.tmp” ??? “文档” ????? ????? ???? ?????? ???? ？。” 用户信息={NSSourceFilePathErrorKey=/Users/ibtdi/Library/Developer/CoreSimulator/Devices/10CB5B13-42C2-4646-934C-67FD33C948C5/data/Containers/Data/Application/F894940C-0D55-4950C-0D55-4950C-0D55-4950C55C55-4950C55C500000000000000000000000000000000000000000000000000 tmp, NSUserStringVariant=( 移动 ), NSDestinationFilePath=/Users/ibtdi/Library/Developer/CoreSimulator/Devices/10CB5B13-42C2-4646-934C-67FD33C948C5/data/Containers/Data/Application/F8905D48C5C5C4F89495C4C5C40C5C5C40C5 /Documents/15287105135b1e4571f2596-new.pdf, NSFilePath=/Users/ibtdi/Library/Developer/CoreSimulator/Devices/10CB5B13-42C2-4646-934C-67FD33C948C5/Data/Application/4F95C5/Data/Application/4F95C5C5/Data/4D95C5C5 E852C1C4B440/tmp/CFNetworkDownload_WBV95z。tmp, NSUnderlyingError=0x604000254460 {Error Domain=NSPOSIXErrorDomain Code=17 "文件存在"}} ???? ？？？“CFNetworkDownload_WBV95z.tmp”？？？“文件”？？？？????? ？？？？？？?????.

这个错误是因为在同一个目录中有一个同名的文件，我尝试使用responseString而不是，responseJSON但它没有解决我的问题，我该怎么办？

Answer 1

您的代码中几乎没有错误：

1. 这是一项Data任务，而不是JSONVadian 指出的任务。

将您的下载功能更改为：

func downloadPdf(pdfReport: String, uniqueName: String, completionHandler:@escaping(String, Bool)->()){

    let downloadUrl: String = URLs.pdfFileUrl + pdfReport
    let destinationPath: DownloadRequest.DownloadFileDestination = { _, _ in
        let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0];
        let fileURL = documentsURL.appendingPathComponent("\(uniqueName).pdf")
        return (fileURL, [.removePreviousFile, .createIntermediateDirectories])
    }
    print(downloadUrl)
    Alamofire.download(downloadUrl, to: destinationPath)
        .downloadProgress { progress in

        }
        .responseData { response in
            print("response: \(response)")
            switch response.result{
            case .success:
                if response.destinationURL != nil, let filePath = response.destinationURL?.absoluteString {
                    completionHandler(filePath, true)
                }
                break
            case .failure:
                completionHandler("", false)
                break
            }

    }
}

2. 你的错误：

   Error Domain=NSPOSIXErrorDomain Code=17 "File exists"

清楚地表明该文件路径中已经有一个文件。所以此代码将删除以前的文件（如果有）。