如何在 Node.js 中使用 axios 配置代理并实现图片并发下载

// server/utils/axiosConfig.ts
const axios = require("axios");
const { HttpsProxyAgent } = require('https-proxy-agent');
// axios 实例
let axiosInstance = null;
// 代理表单（可以从数据库读取相关配置）
let proxyParams = { 
    state: true, 
    host: "127.0.0.1", 
    port: 10809, 
    protocol: "http", 
    username: "", 
    password: ""
};
// 创建 axios 实例 
const createAxiosInstance = () =>  {
    // 判断是否开启代理
    const useProxy = proxyParams['state'] == true;
    let axiosConfig = {
        timeout: 5000
    };
    // 启用代理服务
    if (useProxy && proxyParams) {
        const agent = new HttpsProxyAgent({
            host: proxyParams.host,
            port: proxyParams.port,
            protocol: proxyParams.protocol,
        });
        axiosConfig['httpsAgent'] = agent;
    }
    // 代理服务器 用户名、密码
    if (useProxy && proxyParams['username'] && proxyParams['password']) {
        axiosConfig['auth'] = {
            username: proxyParams['username'],
            password: proxyParams['password']
        };
    }
    axiosInstance = axios.create(axiosConfig);
}
// 获取 Axios 实例
const getAxiosInstance = () => {
    if (!axiosInstance) {
        createAxiosInstance();
    }
    return axiosInstance;
}
// 更新 Axios 实例
const updateAxiosInstance = () => {
    createAxiosInstance();
}
module.exports = {
    getAxiosInstance,
    updateAxiosInstance
};

const { getSettingCache } = require("../db/SettingManager.ts");
const createAxiosInstance = () => {
    // 获取配置信息
    const settingCache = getSettingCache();
    // 判断是否开启代理
    const proxyParams = settingCache["proxy"] ? JSON.parse(settingCache["proxy"]) : null;
    // {
    //   proxy: '{"state":true,"host":"127.0.0.1","port":10809,"protocol":"http","username":"","password":""}',
    // }
}

// server/utils/downloadImages.ts
const { getAxiosInstance } = require('../utils/axiosConfig.ts');
const path = require("path");
const fs = require("fs");
const downloadImagesByUrls = async (imageUrls, savePath) => {
    // 为避免出现循环导入，此处使用动态导入
    const pLimit = (await import('p-limit')).default;
    // 提取 url 中的文件名 例：xxx.jpg
    const filenames = imageUrls.map((url) => path.basename(url));
    // 判断是否存在目标文件夹，不存在则创建
    if (!fs.existsSync(savePath)) {
        fs.mkdirSync(savePath, { recursive: true });
    }
    // 下载单个图片的函数
    const downloadImage = async (url, filename) => {
        // 拼接文件路径
        const fullPath = path.join(savePath, filename);
        try {
            // 获取 axios 实例
            const axiosInstance = await getAxiosInstance();
            const response = await axiosInstance({
                method: "get",
                url: url,
                responseType: "stream",
            });
            const writer = await fs.createWriteStream(fullPath);
            // 用Promise包装stream完成事件
            return new Promise((resolve, reject) => {
                response.data.pipe(writer);
                writer.on("finish", () => resolve({ filename, success: true }));
                writer.on("error", (err) => reject({ filename, success: false, error: err.message }));
                response.data.on("error", (err) => reject({ filename, success: false, error: err.message }));
            });
        } catch (error) {
            return { filename, success: false, error: error.message };
        }
    };
    // 并发控制
    const limit = pLimit(5);
    // 创建下载任务
    const tasks = imageUrls.map((url, index) => 
        limit(() => downloadImage(url, filenames[index]))
    );
    // 执行下载任务并等待所有任务完成
    const results = await Promise.all(tasks);
    return results;
};
module.exports = {
    downloadImagesByUrls,
};