npm i axios --save
npm i qs--save

import axios from 'axios'

import qs from 'qs'

if (process.env.NODE_ENV == 'development') {  

  axios.defaults.baseURL = '/api';

}else if (process.env.NODE_ENV == 'debug') {  

  axios.defaults.baseURL = 'http://v.juhe.cn';

}else if (process.env.NODE_ENV == 'production') {  

  axios.defaults.baseURL = 'http://v.juhe.cn';

}

axios.defaults.headers.post['Content-Type'] = 'application/x-www-form-urlencoded;charset=UTF-8';

axios.defaults.timeout = 10000;

axios.interceptors.request.use(function (config) {
  // 一般在這個(gè)位置判斷token是否存在
  return config;
  }, function (error) {
  // 對(duì)請(qǐng)求錯(cuò)誤做些什么
  return Promise.reject(error);
});

axios.interceptors.response.use(function (response){
   // 處理響應(yīng)數(shù)據(jù)
  if (response.status === 200) {      
    return Promise.resolve(response);    
  } else {      
    return Promise.reject(response);    
  }
  }, function (error){
  // 處理響應(yīng)失敗
  return Promise.reject(error);
});

export function get(url, params){  
  return new Promise((resolve, reject) =>{    
    axios.get(url, {      
      params: params    
    }).then(res => {
      resolve(res.data);
    }).catch(err =>{
      reject(err.data)    
    })  
  });
}

export function post(url, params) {
  return new Promise((resolve, reject) => {
     axios.post(url, qs.stringify(params))
    .then(res => {
      resolve(res.data);
    })
    .catch(err =>{
      reject(err.data)
    })
  });
}

import {get,post} from './utils/api'
//將方法掛載到Vue原型上
Vue.prototype.get = get;
Vue.prototype.post = post;

devServer: {
  historyApiFallback: true,
  hot: true,
  inline: true,
  stats: { colors: true },
  proxy: {
   //匹配代理的url
   '/api': {
     // 目標(biāo)服務(wù)器地址
       target: 'http://v.juhe.cn',
       //路徑重寫
       pathRewrite: {'^/api' : ''},
       changeOrigin: true,
       secure: false,
      }
   },
  disableHostCheck:true
  }

this.get('/toutiao/index?type=top&key=秘鑰',{})
  .then((res)=>{
    if(res.error_code===0){
      resolve(res);
    }else{
      //這里拋出的異常被下面的catch所捕獲
      reject(error);
    }
  })
  .catch((err)=>{
    console.log(err)
  })

  var promise = new Promise((resolve,reject)=>{
    let url1 = '/toutiao/index?type=top&key=秘鑰'
    this.get(url,{})
    .then((res)=>{
      resolve(res);
    })
    .catch((err)=>{
      console.log(err)
    })
  });
  promise.then((res)=>{
    let url2 = '/toutiao/index?type=top&key=秘鑰'
    this.get(ur2,{})
    .then((res)=>{
      //只有當(dāng)url1請(qǐng)求到數(shù)據(jù)后才會(huì)調(diào)用url2，否則等待
      resolve(res);
    })
    .catch((err)=>{
      console.log(err)
    })
  })

var p = Promise.all([p1, p2, p3]);

var p = new Promise( [p1,p2,p3] )

Promise.resolve('foo')
// 等價(jià)于
new Promise(resolve => resolve('foo'))

Promise.reject('foo')
// 等價(jià)于
new Promise(reject => reject('foo'))