Question

我在下面使用此代码发送多部分参数

 let headers = [
        "Content-Type": "application/x-www-form-urlencoded",
        "Authorization": "Bearer \(myToken)",
        "cache-control": "no-cache"
    ]

    let parameters = [
        [
            "name": "firstname",
            "value": "alex"
        ],
        [
            "name": "lastname",
            "value": "black"
        ],
        [
            "name": "birthdate_day",
            "value": "1"
        ],
        [
            "name": "birthdate_month",
            "value": "5"
        ],
        [
            "name": "birthdate_year",
            "value": "1989"
        ],
        [
            "name": "gender",
            "value": "m"
        ],
        [
            "name": "avatar",
            "fileName": "\(imageURL)"
        ]
    ]

    let boundary = "Boundary-\(NSUUID().uuidString)"

    var body = ""
    let error: NSError? = nil
    for param in parameters {
        let paramName = param["name"]!
        body += "--\(boundary)\r\n"
        body += "Content-Disposition:form-data; name=\"\(paramName)\""
        if let filename = param["fileName"] {
            if let contentType = param["content-type"] {
            do {
                let fileContent = try String(contentsOfFile: filename, encoding: String.Encoding.utf8)
                if (error != nil) {
                    print(error as Any)
                }

                body += "; filename=\"\(filename)\"\r\n"
                body += "Content-Type: \(contentType)\r\n\r\n"
                body += fileContent
            } catch {
                print(error)
            }
            }
        } else if let paramValue = param["value"] {
            body += "\r\n\r\n\(paramValue)"
        }
    }

    let postData = NSMutableData(data: body.data(using: String.Encoding.utf8)!)

    let request = NSMutableURLRequest(url: NSURL(string: "myUrl")! as URL,
                                      cachePolicy: .useProtocolCachePolicy,
                                      timeoutInterval: 10.0)
    request.httpMethod = "POST"
    request.allHTTPHeaderFields = headers
    request.httpBody = postData as Data

    let session = URLSession.shared
    let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
        if (error != nil) {
            print(error as Any)
        } else {
            let httpResponse = response as? HTTPURLResponse
            print(httpResponse?.statusCode as Any)
        }
    })

    dataTask.resume()
    return dataTask

图像URL和其余数据，但是我将收到Satus代码500，我知道此错误是在服务器端，但是android版本使用的是相同的api URL，并且运行良好，我知道此代码可以修复，并且也许很小的改动就能解决此代码的工作问题

Answer 1

由于Swift 3使用URL而不是NSURL，并且

var request = URLRequest是可变的，请使用它代替NSMutableURLRequest
var data = Data()是可变的，请使用它代替NSMutableData
使用Data(contentsOf:options:)方法安全地添加文件Blob数据
content-type参数缺失，因此使用if let contentType = param["content-type"] { ... }默认的哑剧类型，application/octet-stream将无法继续
取决于服务器，可能需要为上传提供文件名

我解决了所有上述问题，并将URLRequest.httpBody生成的代码移至以下扩展名。

extension URLRequest {
    private func formHeader(_ name: String, crlf: String, fileName: String? = nil, mimeType: String? = nil) -> String {
        var str = "\(crlf)Content-Disposition: form-data; name=\"\(name)\""
        guard fileName != nil || mimeType != nil else { return str + crlf + crlf }

        if let name = fileName {
            str += "; filename=\"\(name)\""
        }
        str += crlf
        if let type = mimeType {
            str += "Content-Type: \(type)\(crlf)"
        }
        return str + crlf
    }

    private func getFileUrl(_ file: Any) -> URL? {
        if let url = file as? String {
            return URL(string: url)
        }
        return file as? URL
    }

    private func getFileData(_ url: URL) -> Data? {
        do {
            return try Data(contentsOf: url, options: .mappedIfSafe)
        } catch {
            print(error)
            return nil
        }
    }

    mutating func setPost(body parameters: [[String: Any]]) {
        let boundary = "Boundary+\(arc4random())\(arc4random())"
        self.setValue("multipart/form-data; boundary=\(boundary)", forHTTPHeaderField: "Content-Type")

        var data = Data()
        data.append("--\(boundary)".data(using: .utf8)!)

        let crlf = "\r\n"
        for parameter in parameters {
            guard let paramName = parameter["name"] as? String else { continue }

            if let value = parameter["value"] {
                let header = formHeader(paramName, crlf: crlf)
                data.append("\(header)\(value)".data(using: .utf8)!)
            } else if let file = parameter["file"], let fileUrl = getFileUrl(file), let fileData = getFileData(fileUrl) {
                let fileName = parameter["fileName"] as? String
                let contentType = parameter["content-type"] as? String
                let header = formHeader(paramName, crlf: crlf, fileName: fileName ?? fileUrl.lastPathComponent, mimeType: contentType ?? "application/octet-stream")
                data.append(header.data(using: .utf8)!)
                data.append(fileData)
            } else {
                print("\(paramName): empty or invalid value")
                continue
            }
            data.append("\(crlf)--\(boundary)".data(using: .utf8)!)
        }
        data.append("--\(crlf)".data(using: .utf8)!)
        self.httpBody = data
        self.httpMethod = "POST"
    }
}

用法

let parameters = [
    ["name": "firstname", "value": "alex"],
    ["name": "avatar", "file": URL],
    ["name": "avatar", "file": "file:///", "fileName": "image.png", "content-type": "image/png"]
]
request.setPost(body: parameters)

在参数中

注意

file键代表URL对象或文件路径字符串。
fileName: image.png用于后端，代表文件名。

最后添加标题并创建URLSession.shared.dataTask作为原始代码。

Update-2 功能而不是扩展名

func getParameterData(_ name: String, parameter: [String : Any]) -> Data? {
    var str = "\r\nContent-Disposition: form-data; name=\"\(name)\""

    if let value = parameter["value"] {
        return "\(str)\r\n\r\n\(value)".data(using: .utf8)!
    }

    guard
        let file = parameter["file"],
        let url = (file is String ? URL(string: file as! String) : file as? URL)
    else {
        return nil
    }

    let data: Data
    do {
        data = try Data(contentsOf: url, options: .mappedIfSafe)
    } catch {
        print(error)
        return nil
    }

    let fileName = (parameter["fileName"] as? String) ?? url.lastPathComponent
    str += "; filename=\"\(fileName)\"\r\n"

    let contentType = (parameter["content-type"] as? String) ?? "application/octet-stream"
    str += "Content-Type: \(contentType)\r\n"

    return (str + "\r\n").data(using: .utf8)! + data
}

func setPostRequestBody(_ request: inout URLRequest, parameters: [[String: Any]]) {
    let boundary = "Boundary+\(arc4random())\(arc4random())"
    request.setValue("multipart/form-data; boundary=\(boundary)", forHTTPHeaderField: "Content-Type")

    var data = Data()
    data.append("--\(boundary)".data(using: .utf8)!)

    for parameter in parameters {
        guard
            let name = parameter["name"] as? String,
            let value = getParameterData(name, parameter: parameter)
        else {
            continue
        }

        data.append(value)
        data.append("\r\n--\(boundary)".data(using: .utf8)!)
    }
    data.append("--\r\n".data(using: .utf8)!)
    request.httpBody = data
}

用法2

var request = URLRequest(url: URL(string: "myUrl")!, cachePolicy: .useProtocolCachePolicy, timeoutInterval: 10.0)
setPostRequestBody(&request, parameters: [
    ["name": "firstname", "value": "alex"],
    ["name": "avatar", "file": URL object or path String]
])

let dataTask = URLSession.shared.dataTask(with: request) { data, response, error in
    guard error != nil else {
        print(error!.localizedDescription)
        return
    }

    let statusCocde = (response as? HTTPURLResponse)?.statusCode
    print(statusCode ?? 0)
    if let data = data {
        print(String(data: data, encoding: .utf8) ?? "")
    }
}
dataTask.resume()

快速发送多部分表格数据

1 个答案: