axios 安装

npm install axios

import axios from 'axios';

import Qs from 'qs'

这里可以使用开头引入的Qs（这个模块在安装axios的时候就已经安装了，不需要另外安装）

全局 axios 默认配置

axios.defaults.baseURL = 'https://api.example.com';
axios.defaults.headers.common['Authorization'] = AUTH_TOKEN;
axios.defaults.headers.post['Content-Type'] = 'application/x-www-form-urlencoded';

自定义实例默认配置

// Set config defaults when creating the instance
var instance = axios.create({
  baseURL: 'https://api.example.com'
});

// Alter defaults after instance has been created
instance.defaults.headers.common['Authorization'] = AUTH_TOKEN;

配置的优先顺序

var instance = axios.create();

instance.defaults.timeout = 2500;

instance.get('/longRequest', {  timeout: 5000}); 

// 添加一个请求拦截器

axios.interceptors.request.use(function (config) { 

   // Do something before request is sent   

 return config;

  }, function (error) {   

 // Do something with request error   

 return Promise.reject(error); 

 });

// 添加一个响应拦截器

axios.interceptors.response.use(function (response) {  

  // Do something with response data   

 return response;

  }, function (error) {  

  // Do something with response error  

  return Promise.reject(error);  

});

移除一个拦截器：

var myInterceptor = axios.interceptors.request.use(function () {/*...*/});
axios.interceptors.request.eject(myInterceptor);

你可以给一个自定义的 axios 实例添加拦截器：

var instance = axios.create();
instance.interceptors.request.use(function () {/*...*/});