Electron React请求本地C++ HTTP服务器遇net::ERR_CONNECTION_RESET问题

本地运行C++编写的HTTP服务器，通过动态端口向Electron React前端传输数据。服务器已确认正常：curl可获取响应，Firefox能打开生成的JSON数据，但Chrome/Electron无法访问——请求已启用的8080端口时返回：

Trying to fetch data from http://localhost:8080/simdata
GET http://localhost:8080/simdata net::ERR_CONNECTION_RESET

请求未使用的端口（如8083）则返回：

GET http://localhost:8083/simdata net::ERR_CONNECTION_REFUSED

已尝试改用127.0.0.1替代localhost、配置allowInsecureContent、调整CORS设置、禁用缓存等方案，问题仍未解决。

相关代码 #

C++服务器核心代码

// 示例代码，替换为实际业务代码
#include <iostream>
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
#include <unistd.h>

int main() {
    int server_fd, new_socket;
    struct sockaddr_in address;
    int opt = 1;
    int addrlen = sizeof(address);
    std::string json_data = "{\"data\": \"sample\"}";

    // 创建socket文件描述符
    if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) {
        perror("socket failed");
        exit(EXIT_FAILURE);
    }

    // 设置socket复用选项
    if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &opt, sizeof(opt))) {
        perror("setsockopt");
        exit(EXIT_FAILURE);
    }

    address.sin_family = AF_INET;
    address.sin_addr.s_addr = INADDR_ANY;
    address.sin_port = htons(8080);

    // 绑定端口
    if (bind(server_fd, (struct sockaddr *)&address, sizeof(address))<0) {
        perror("bind failed");
        exit(EXIT_FAILURE);
    }

    // 监听连接
    if (listen(server_fd, 3) < 0) {
        perror("listen");
        exit(EXIT_FAILURE);
    }

    while(true) {
        if ((new_socket = accept(server_fd, (struct sockaddr *)&address, (socklen_t*)&addrlen))<0) {
            perror("accept");
            exit(EXIT_FAILURE);
        }

        // 构造响应
        std::string response = "HTTP/1.1 200 OK\r\n";
        response += "Content-Type: application/json\r\n";
        response += "Access-Control-Allow-Origin: *\r\n";
        response += "\r\n";
        response += json_data;

        send(new_socket, response.c_str(), response.length(), 0);
        close(new_socket);
    }

    return 0;
}

React请求代码

// 示例代码，替换为实际业务代码
import { useEffect } from 'react';

function App() {
    useEffect(() => {
        const fetchData = async () => {
            try {
                console.log('Trying to fetch data from http://localhost:8080/simdata');
                const response = await fetch('http://localhost:8080/simdata');
                const data = await response.json();
                console.log(data);
            } catch (error) {
                console.error(error);
            }
        };

        fetchData();
    }, []);

    return <div>Data Fetch Test</div>;
}

export default App;

1. 调整Electron主进程网络安全配置 #

Electron默认Web安全策略可能拦截localhost请求，可在主进程中修改配置：

const { app, BrowserWindow } = require('electron');

function createWindow() {
    const mainWindow = new BrowserWindow({
        webPreferences: {
            // 临时关闭Web安全（仅测试用，生产环境建议用严格CSP）
            webSecurity: false,
            // 或配置精准内容安全策略，允许访问目标端口
            // contentSecurityPolicy: "connect-src 'self' http://localhost:8080 http://127.0.0.1:8080;"
        }
    });

    mainWindow.loadURL('http://localhost:3000'); // React开发服务器地址
}

app.whenReady().then(createWindow);

2. 修复C++服务器连接处理逻辑 #

确保服务器完整处理HTTP请求生命周期：

• 读取完整的客户端请求（避免未读数据导致连接异常）
• 发送完整的响应头部（含CORS和连接管理字段）
• 响应后正确关闭连接

修改后的C++服务器响应逻辑示例：

// 先读取客户端请求内容，避免连接阻塞
char buffer[1024] = {0};
read(new_socket, buffer, 1024);

// 构造完整响应
std::string response = "HTTP/1.1 200 OK\r\n";
response += "Content-Type: application/json\r\n";
response += "Access-Control-Allow-Origin: *\r\n";
response += "Access-Control-Allow-Methods: GET, OPTIONS\r\n";
response += "Access-Control-Allow-Headers: Content-Type\r\n";
response += "Connection: close\r\n"; // 明确关闭连接
response += "\r\n";
response += json_data;

send(new_socket, response.c_str(), response.size(), 0);
shutdown(new_socket, SHUT_RDWR); // 先关闭读写再释放socket
close(new_socket);

3. 禁用Electron代理设置 #

系统代理可能拦截localhost请求，在主进程中添加：

app.commandLine.appendSwitch('no-proxy-server');

4. 验证服务器绑定地址 #

确保C++服务器绑定到0.0.0.0（而非仅127.0.0.1），允许所有网络接口访问：

address.sin_addr.s_addr = INADDR_ANY;

内容的提问来源于stack exchange，提问作者H 1