使用 winHttp 和 C++ 将 png 图像发送到服务器时失败

Question

我是 winHttp 的新手，一直坚持将 png 图像作为附件发送到服务器。我使用 C++ 创建了一个 exe 只是为了解决这个问题。不知何故，我设法连接到服务器，它给出了以下响应，

{"code":"9999","message":"org.springframework.web.multipart.support.MissingServletRequestPartException: Required request part 'attachment' is not present","cause":".","correlationID":"***-***-43f4-82b2-***","apiURL":"POST : /file/4856.png","origin":"PartMfgServer","timestamp":1704814609769}

这是我的BE代码，

@PostMapping(path = "/{fileName}",  consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
public String uploadFileFromServer(@RequestHeader("File-Type") String contentType,
                                   @PathVariable("fileName") String fileName,
                                   @RequestParam(value = "fileRole", required = false) FILE_ROLE fileRole,
                                   @RequestParam("attachment") MultipartFile fileToUpload) 
{.......}

这是我的代码，

int main() {
    LPCWSTR server = L"amn.dm-labs.com";
    LPCWSTR path = L"api/v2307/file/4856.png";

    HINTERNET hSession = WinHttpOpen(L"ImageUploader/1.0", WINHTTP_ACCESS_TYPE_DEFAULT_PROXY, WINHTTP_NO_PROXY_NAME, WINHTTP_NO_PROXY_BYPASS, 0);
    if (!hSession) {
        return -1;
    }

    HINTERNET hConnect = WinHttpConnect(hSession, server, INTERNET_DEFAULT_HTTPS_PORT, 0);
    if (!hConnect) {
        std::cerr << "WinHttpConnect failed!" << std::endl;
        WinHttpCloseHandle(hSession);
        return -1;
    }

    HINTERNET hRequest = WinHttpOpenRequest(hConnect, L"POST", path, NULL, WINHTTP_NO_REFERER, WINHTTP_DEFAULT_ACCEPT_TYPES, WINHTTP_FLAG_SECURE);
    if (!hRequest) {
        // Handle connection error
        WinHttpCloseHandle(hConnect);
        WinHttpCloseHandle(hSession);
        return -1;
    }

    // Open image file for reading
    HANDLE hFile = CreateFile(L"C:\\Users\\m5zmfk\\AppData\\Local\\Temp\\nxOpen\\partfiles\\4856\\4856.png", GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
    if (hFile == INVALID_HANDLE_VALUE) {
        // Handle file open error
        WinHttpCloseHandle(hRequest);
        WinHttpCloseHandle(hConnect);
        WinHttpCloseHandle(hSession);
        return -1;
    }


    DWORD fileSize = GetFileSize(hFile, NULL);
    std::wstring boundary = L"---------------------------1234567890";
 //   std::wstring endBoundary = L"\r\n--" + boundary + L"--\r\n";


    std::wstring formDataBody = L"--" + boundary + L"\r\n"
        L"Content-Disposition: form-data; name=\"attachment\"; filename=\"4856.png\"\r\n"
        L"\r\n--" + boundary + L"--\r\n";

    std::wstring headers = L"authorization: ****\r\n"
        L"Content-Type: multipart/form-data; boundary=" + boundary + L"\r\n"
        L"File-Type: image/png\r\n"
        L"Content-Length: " + std::to_wstring(fileSize + formDataBody.length()) +L"\r\n";

    bool success = WinHttpAddRequestHeaders(hRequest, headers.c_str(), headers.length(), WINHTTP_ADDREQ_FLAG_ADD);

    if (!success) {
        std::cout << "Error adding headers" << std::endl;
        printLastError(GetLastError());
    }

    DWORD timeout = 60000 * 2; // Set timeout to 60 seconds (adjust as needed)
    WinHttpSetOption(hRequest, WINHTTP_OPTION_RECEIVE_TIMEOUT, &timeout, sizeof(timeout));
    WinHttpSetOption(hRequest, WINHTTP_OPTION_SEND_TIMEOUT, &timeout, sizeof(timeout));

    if (!WinHttpSendRequest(hRequest, WINHTTP_NO_ADDITIONAL_HEADERS, 0, WINHTTP_NO_REQUEST_DATA, 0, 0, 0)) {
        // Handle request send error
        printLastError(GetLastError());
        CloseHandle(hFile);
        WinHttpCloseHandle(hRequest);
        WinHttpCloseHandle(hConnect);
        WinHttpCloseHandle(hSession);
        return -1;
    }

    DWORD bytesWritten;
    // Build the form-data request body
   
    success = WinHttpWriteData(hRequest, formDataBody.c_str(), formDataBody.length(), &bytesWritten);

    if (!success) {
        printLastError(GetLastError());
        CloseHandle(hFile);
        WinHttpCloseHandle(hRequest);
        WinHttpCloseHandle(hConnect);
        WinHttpCloseHandle(hSession);
        return -1;
    }

    // Write the file content
    BYTE buffer[1024];
    DWORD bytesRead;
    while (ReadFile(hFile, buffer, sizeof(buffer), &bytesRead, NULL) && bytesRead > 0) {
        success = WinHttpWriteData(hRequest, buffer, bytesRead, &bytesWritten);
        if (!success) {
            printLastError(GetLastError());
            CloseHandle(hFile);
            WinHttpCloseHandle(hRequest);
            WinHttpCloseHandle(hConnect);
            WinHttpCloseHandle(hSession);
            return -1;
        }
    }

    if (!WinHttpReceiveResponse(hRequest, NULL)) {
        // Handle response error
        printLastError(GetLastError());
        CloseHandle(hFile);
        WinHttpCloseHandle(hRequest);
        WinHttpCloseHandle(hConnect);
        WinHttpCloseHandle(hSession);
        return -1;
    }

    // Read and print the response
    DWORD resRead;
    BYTE resBuffer[1024];
    while (WinHttpReadData(hRequest, resBuffer, sizeof(resBuffer), &resRead) && resRead > 0) {
        // Process the received data (you can print it or save it to a file, etc.)
        std::cout.write(reinterpret_cast<const char*>(resBuffer), resRead);
    }

    // Close the file and WinHTTP handles
    CloseHandle(hFile);
    WinHttpCloseHandle(hRequest);
    WinHttpCloseHandle(hConnect);
    WinHttpCloseHandle(hSession);

    return 0;
}

任何人都可以帮我解决出什么问题吗？

我尝试使用

formDataBody

将

WinHttpAddRequestHeaders

作为标题。我收到错误代码 87。

 std::wstring formDataBody = L"--" + boundary + L"\r\n"
        L"Content-Disposition: form-data; name=\"attachment\"; filename=\"4856.png\"\r\n"
        L"\r\n--" + boundary + L"--\r\n";

Answer 1

您没有正确发送 PNG 数据。它需要位于您的 formDataBody 变量内，作为标头之后、结束边界之前的

attachment

MIME 部分的主体。您试图在 MIME 数据之后发送 PNG 数据，这是错误的。此外，

File-Type

不是可识别的 HTTP 标头。您需要在

Content-Type

MIME 部分包含

attachment

标头。此外，MIME 基于 7 位 ASCII，因此您不应该对

std::wstring

变量使用

formDataBody

，而应使用

std::string

（对 WinHTTP 调用使用

std::wstring

就可以了）。尝试更多类似这样的事情：

bool readAll(HANDLE hFile, void *buffer, DWORD bufsize) {
    char *pBuffer = static_cast<char*>(buffer);
    DWORD dwNumRead;

    while (bufsize != 0) {
        if (!ReadFile(hFile, pBuffer, bufsize, &dwNumRead, NULL)) {
            return false;
        }
        pBuffer += dwNumRead;
        bufsize -= dwNumRead;
    }
    
    return true;
}

void printFailure(const char *funcName) {
    DWORD dwError = GetLastError();
    std::cerr << funcName << " failed!" << std::endl;
    printLastError(dwError);
}

int main() {
    LPCWSTR server = L"amn.dm-labs.com";
    LPCWSTR path = L"api/v2307/file/4856.png";
    
    HANDLE hFile = CreateFile(L"C:\\Users\\m5zmfk\\AppData\\Local\\Temp\\nxOpen\\partfiles\\4856\\4856.png", GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
    if (hFile == INVALID_HANDLE_VALUE) {
        printFailure("CreateFile");
        return -1;
    }

    DWORD fileSize = GetFileSize(hFile, NULL);
    if (fileSize == ERROR_INVALID_FILE_SIZE) {
        printFailure("GetFileSize");
        CloseHandle(hFile);
        return -1;
    }

    std::string fileData;
    if (fileSize > 0) {
        fileData.resize(fileSize);
        if (!readAll(hFile, &fileData[0], fileSize)) {
            printFailure("ReadFile");
            CloseHandle(hFile);
            return -1;
        }
    }

    CloseHandle(hFile);

    HINTERNET hSession = WinHttpOpen(L"ImageUploader/1.0", WINHTTP_ACCESS_TYPE_DEFAULT_PROXY, WINHTTP_NO_PROXY_NAME, WINHTTP_NO_PROXY_BYPASS, 0);
    if (!hSession) {
        printFailure("WinHttpOpen");
        return -1;
    }

    HINTERNET hConnect = WinHttpConnect(hSession, server, INTERNET_DEFAULT_HTTPS_PORT, 0);
    if (!hConnect) {
        printFailure("WinHttpConnect");
        WinHttpCloseHandle(hSession);
        return -1;
    }

    HINTERNET hRequest = WinHttpOpenRequest(hConnect, L"POST", path, NULL, WINHTTP_NO_REFERER, WINHTTP_DEFAULT_ACCEPT_TYPES, WINHTTP_FLAG_SECURE);
    if (!hRequest) {
        printFailure("WinHttpOpenRequest");
        WinHttpCloseHandle(hConnect);
        WinHttpCloseHandle(hSession);
        return -1;
    }
    
    std::string sBoundary =   "---------------------------1234567890";
    std::wstring wBoundary = L"---------------------------1234567890";

    std::string formDataBody = "--" + sBoundary + "\r\n"
        "Content-Disposition: form-data; name=\"attachment\"; filename=\"4856.png\"\r\n"
        "Content-Type: image/png\r\n"
        "\r\n" +
        sFileData + "\r\n"
        "--" + sBoundary + "--\r\n";

    std::wstring headers = L"authorization: ****\r\n"
        L"Content-Type: multipart/form-data; boundary=" + wBoundary + L"\r\n"
        L"Content-Length: " + std::to_wstring(formDataBody.length()) + L"\r\n";

    DWORD timeout = 60000 * 2; // Set timeout to 60 seconds (adjust as needed)
    WinHttpSetOption(hRequest, WINHTTP_OPTION_RECEIVE_TIMEOUT, &timeout, sizeof(timeout));
    WinHttpSetOption(hRequest, WINHTTP_OPTION_SEND_TIMEOUT, &timeout, sizeof(timeout));

    if (!WinHttpSendRequest(hRequest, headers.c_str(), headers.length(), formDataBody.c_str(), formDataBody.length(), formDataBody.length(), 0)) {
        printFailure("WinHttpSendRequest");
        WinHttpCloseHandle(hRequest);
        WinHttpCloseHandle(hConnect);
        WinHttpCloseHandle(hSession);
        return -1;
    }

    if (!WinHttpReceiveResponse(hRequest, NULL)) {
        printFailure("WinHttpReceiveResponse");
        WinHttpCloseHandle(hRequest);
        WinHttpCloseHandle(hConnect);
        WinHttpCloseHandle(hSession);
        return -1;
    }

    // Read and print the response
    DWORD resRead;
    char resBuffer[1024];
    do {
        if (!WinHttpReadData(hRequest, resBuffer, sizeof(resBuffer), &resRead)) {
            printFailure("WinHttpReadData");
            WinHttpCloseHandle(hRequest);
            WinHttpCloseHandle(hConnect);
            WinHttpCloseHandle(hSession);
            return -1;
        }
        
        if (resRead == 0)
            break;

        std::cout.write(resBuffer, resRead);
    }
    while (true);

    WinHttpCloseHandle(hRequest);
    WinHttpCloseHandle(hConnect);
    WinHttpCloseHandle(hSession);

    return 0;
}

或者，如果您确实想使用 

WinHttpWriteData()

以块的形式发送 PNG 数据，那么它需要看起来更像这样：

void printFailure(const char *funcName) {
    DWORD dwError = GetLastError();
    std::cerr << funcName << " failed!" << std::endl;
    printLastError(dwError);
}

int main() {
    LPCWSTR server = L"amn.dm-labs.com";
    LPCWSTR path = L"api/v2307/file/4856.png";
    
    HANDLE hFile = CreateFile(L"C:\\Users\\m5zmfk\\AppData\\Local\\Temp\\nxOpen\\partfiles\\4856\\4856.png", GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
    if (hFile == INVALID_HANDLE_VALUE) {
        printFailure("CreateFile");
        return -1;
    }

    DWORD fileSize = GetFileSize(hFile, NULL);
    if (fileSize == ERROR_INVALID_FILE_SIZE) {
        printFailure("GetFileSize");
        CloseHandle(hFile);
        return -1;
    }

    HINTERNET hSession = WinHttpOpen(L"ImageUploader/1.0", WINHTTP_ACCESS_TYPE_DEFAULT_PROXY, WINHTTP_NO_PROXY_NAME, WINHTTP_NO_PROXY_BYPASS, 0);
    if (!hSession) {
        printFailure("WinHttpOpen");
        CloseHandle(hFile);
        return -1;
    }

    HINTERNET hConnect = WinHttpConnect(hSession, server, INTERNET_DEFAULT_HTTPS_PORT, 0);
    if (!hConnect) {
        printFailure("WinHttpConnect");
        WinHttpCloseHandle(hSession);
        CloseHandle(hFile);
        return -1;
    }

    HINTERNET hRequest = WinHttpOpenRequest(hConnect, L"POST", path, NULL, WINHTTP_NO_REFERER, WINHTTP_DEFAULT_ACCEPT_TYPES, WINHTTP_FLAG_SECURE);
    if (!hRequest) {
        printFailure("WinHttpOpenRequest");
        WinHttpCloseHandle(hConnect);
        WinHttpCloseHandle(hSession);
        CloseHandle(hFile);
        return -1;
    }

    std::string sBoundary =   "---------------------------1234567890";
    std::wstring wBoundary = L"---------------------------1234567890";

    std::string formDataBody1 = "--" + sBoundary + "\r\n"
        "Content-Disposition: form-data; name=\"attachment\"; filename=\"4856.png\"\r\n"
        "Content-Type: image/png\r\n"
        "\r\n";

    std::string formDataBody2 = "\r\n"
        "--" + sBoundary + "--\r\n";

    DWORD dwTotalLength = formDataBody1.length() + fileSize + formDataBody2.length();
    DWORD dwBytesWritten;
    
    std::wstring headers = L"authorization: ****\r\n"
        L"Content-Type: multipart/form-data; boundary=" + wBoundary + L"\r\n";

    DWORD timeout = 60000 * 2; // Set timeout to 60 seconds (adjust as needed)
    WinHttpSetOption(hRequest, WINHTTP_OPTION_RECEIVE_TIMEOUT, &timeout, sizeof(timeout));
    WinHttpSetOption(hRequest, WINHTTP_OPTION_SEND_TIMEOUT, &timeout, sizeof(timeout));

    if (!WinHttpSendRequest(hRequest, headers.c_str(), headers.length(), WINHTTP_NO_REQUEST_DATA, 0, dwTotalLength, 0)) {
        printFailure("WinHttpSendRequest");
        WinHttpCloseHandle(hRequest);
        WinHttpCloseHandle(hConnect);
        WinHttpCloseHandle(hSession);
        CloseHandle(hFile);
        return -1;
    }

    if (!WinHttpWriteData(hRequest, formDataBody1.c_str(), formDataBody1.length(), &dwBytesWritten)) {
        printFailure("WinHttpWriteData");
        WinHttpCloseHandle(hRequest);
        WinHttpCloseHandle(hConnect);
        WinHttpCloseHandle(hSession);
        CloseHandle(hFile);
        return -1;
    }

    BYTE buffer[1024];
    DWORD bytesRead;

    do {
        if (!ReadFile(hFile, buffer, sizeof(buffer), &bytesRead, NULL)) {
            printFailure("ReadFile");
            WinHttpCloseHandle(hRequest);
            WinHttpCloseHandle(hConnect);
            WinHttpCloseHandle(hSession);
            CloseHandle(hFile);
            return -1;
        }
        
        if (bytesRead == 0)
            break;
            
        if (!WinHttpWriteData(hRequest, buffer, bytesRead, &bytesWritten)) {
            printFailure("WinHttpWriteData");
            WinHttpCloseHandle(hRequest);
            WinHttpCloseHandle(hConnect);
            WinHttpCloseHandle(hSession);
            CloseHandle(hFile);
            return -1;
        }
    }
    while (true);
    
    CloseHandle(hFile);

    if (!WinHttpWriteData(hRequest, formDataBody2.c_str(), formDataBody2.length(), &dwBytesWritten)) {
        printFailure("WinHttpWriteData");
        WinHttpCloseHandle(hRequest);
        WinHttpCloseHandle(hConnect);
        WinHttpCloseHandle(hSession);
        CloseHandle(hFile);
        return -1;
    }

    if (!WinHttpReceiveResponse(hRequest, NULL)) {
        printFailure("WinHttpReceiveResponse");
        WinHttpCloseHandle(hRequest);
        WinHttpCloseHandle(hConnect);
        WinHttpCloseHandle(hSession);
        return -1;
    }

    char resBuffer[1024];

    do {
        if (!WinHttpReadData(hRequest, resBuffer, sizeof(resBuffer), &bytesRead)) {
            printFailure("WinHttpReadData");
            WinHttpCloseHandle(hRequest);
            WinHttpCloseHandle(hConnect);
            WinHttpCloseHandle(hSession);
            return -1;
        }
        
        if (bytesRead == 0)
            break;
            
        std::cout.write(resBuffer, bytesRead);
    }
    while (true);

    WinHttpCloseHandle(hRequest);
    WinHttpCloseHandle(hConnect);
    WinHttpCloseHandle(hSession);

    return 0;
}