XHR / Fetch / Axios 请求的取消请求与请求重试

XHR / Fetch / Axios 请求的取消请求与请求重试是前端性能优化与稳定性处理的重点，也是面试高频内容。下面是这三种方式的详解封装方案（可直接复用）。

✅ 一、Axios 取消请求与请求重试封装

1. 安装依赖（可选，用于扩展）

npm install axios

2. 封装 cancelToken 与 retry 的 axios 请求模块

// axiosRequest.js
import axios from 'axios'const pendingMap = new Map()// 生成唯一 key（用于标记请求）
function getRequestKey(config) {const { method, url, params, data } = configreturn [method, url, JSON.stringify(params), JSON.stringify(data)].join('&')
}// 添加请求到 pendingMap
function addPending(config) {const key = getRequestKey(config)config.cancelToken = new axios.CancelToken(cancel => {if (!pendingMap.has(key)) {pendingMap.set(key, cancel)}})
}// 移除请求
function removePending(config) {const key = getRequestKey(config)if (pendingMap.has(key)) {const cancel = pendingMap.get(key)cancel && cancel()pendingMap.delete(key)}
}// 重试机制封装
function retryAdapterEnhancer(adapter, options = {}) {const { retries = 3, delay = 1000 } = optionsreturn async config => {let retryCount = 0const request = async () => {try {return await adapter(config)} catch (err) {if (retryCount < retries) {retryCount++await new Promise(res => setTimeout(res, delay))return request()} else {return Promise.reject(err)}}}return request()}
}// 创建实例
const axiosInstance = axios.create({timeout: 5000,adapter: retryAdapterEnhancer(axios.defaults.adapter, { retries: 2, delay: 1000 })
})// 请求拦截器
axiosInstance.interceptors.request.use(config => {removePending(config)addPending(config)return config
})// 响应拦截器
axiosInstance.interceptors.response.use(response => {removePending(response.config)return response},error => {if (axios.isCancel(error)) {console.warn('Request canceled:', error.message)}return Promise.reject(error)}
)export default axiosInstance

✅ 使用示例：

import request from './axiosRequest'request.get('/api/data', { params: { id: 1 } }).then(res => console.log(res)).catch(err => console.error(err))

✅ 二、Fetch 封装（支持取消请求 & 重试）

1. 使用 AbortController 封装取消与重试

// fetchRequest.js
export function fetchWithRetry(url, options = {}, retries = 3, delay = 1000) {const controller = new AbortController()options.signal = controller.signalconst fetchData = (retryCount = 0) => {return fetch(url, options).then(res => {if (!res.ok) throw new Error('Network response was not ok')return res}).catch(err => {if (retryCount < retries && err.name !== 'AbortError') {return new Promise(resolve =>setTimeout(() => resolve(fetchData(retryCount + 1)), delay))}throw err})}return {promise: fetchData(),cancel: () => controller.abort()}
}

✅ 使用示例：

const { promise, cancel } = fetchWithRetry('/api/data', {}, 2, 1000)promise.then(res => res.json()).then(data => console.log(data)).catch(err => console.error(err))// 调用 cancel() 可随时取消请求

✅ 三、XHR 原生封装（带取消 & 重试）

// xhrRequest.js
export function xhrWithRetry({ url, method = 'GET', data = null, retries = 3, delay = 1000 }) {let xhr = nullconst send = (retryCount = 0, resolve, reject) => {xhr = new XMLHttpRequest()xhr.open(method, url, true)xhr.onreadystatechange = () => {if (xhr.readyState === 4) {if (xhr.status >= 200 && xhr.status < 300) {resolve(xhr.responseText)} else if (retryCount < retries) {setTimeout(() => send(retryCount + 1, resolve, reject), delay)} else {reject(new Error(`Request failed: ${xhr.status}`))}}}xhr.onerror = () => reject(new Error('Network Error'))xhr.send(data)}const promise = new Promise((resolve, reject) => send(0, resolve, reject))return {promise,cancel: () => xhr && xhr.abort()}
}

✅ 使用示例：

const { promise, cancel } = xhrWithRetry({ url: '/api/data' })promise.then(res => console.log(res)).catch(err => console.error(err))// 可随时调用取消
cancel()

✅ 总结对比

特性/方式	取消支持	重试支持	易用性	推荐场景
Axios	✔️ CancelToken	✔️ 自定义 adapter	✅ 最佳	Vue/React 项目
Fetch	✔️ AbortController	✔️ 手动封装	✅ 清晰	原生 / SSR 项目
XHR	✔️ abort()	✔️ 手动封装	❌ 复杂	老旧兼容需求