dev: {

    // Paths
    assetsSubDirectory: 'static',
    assetsPublicPath: '/',

    // Various Dev Server settings
    host: 'localhost', // can be overwritten by process.env.HOST
    port: 8080, // can be overwritten by process.env.PORT, if port is in use, a free one will be determined
    autoOpenBrowser: true,
    proxyTable: {
      '/api': {  //代理地址
        target: 'http://localhost:9000/hadsource',  //需要代理的地址
        changeOrigin: true,  //是否跨域
        secure: false,
        pathRewrite: {
          '^/api': '/'   //本身的接口地址没有 '/api' 这种通用前缀，所以要rewrite，如果本身有则去掉
        }
      }
    },
    disableHostCheck: true,
    errorOverlay: true,
    notifyOnErrors: true,
    poll: false, // https://webpack.js.org/configuration/dev-server/#devserver-watchoptions-

    // Use Eslint Loader?
    // If true, your code will be linted during bundling and
    // linting errors and warnings will be shown in the console.
    useEslint: false,
    // If true, eslint errors and warnings will also be shown in the error overlay
    // in the browser.
    showEslintErrorsInOverlay: false,

    /**
     * Source Maps
     */

    // https://webpack.js.org/configuration/devtool/#development
    devtool: 'cheap-module-eval-source-map',

    // If you have problems debugging vue-files in devtools,
    // set this to false - it *may* help
    // https://vue-loader.vuejs.org/en/options.html#cachebusting
    cacheBusting: true,

    cssSourceMap: true
  },

import axios from 'axios'
import { Message } from 'element-ui'
import router from '../router'

// create an axios instance
const service = axios.create({
  baseURL: process.env.VUE_APP_BASE_API, // url = base url + request url
  // withCredentials: true, // send cookies when cross-domain requests
  timeout: 120000 // request timeout
})

// request interceptor
service.interceptors.request.use(
  config => {
    // do something before request is sent
    return config
  },
  error => {
    // do something with request error
    console.log(error) // for debug
    return Promise.reject(error)
  }
)

// response interceptor
service.interceptors.response.use(
  /**
   * If you want to get http information such as headers or status
   * Please return  response => response
  */

  /**
   * Determine the request status by custom code
   * Here is just an example
   * You can also judge the status by HTTP Status Code
   */
  response => {
    const res = response
    // if the custom code is not 20000, it is judged as an error.
    if (res.status && res.status !== 200) {
      if (res.status === 40301) {
        Message({
          message: '登录已过期请重新登录',
          type: 'error',
          duration: 5 * 1000
        })
        router.push(`/login?redirect=index`)
      } else {
        Message({
          message: res.message || '网络异常',
          type: 'warning',
          duration: 5 * 1000
        })
      }
      return Promise.reject(new Error(res.message || 'Error'))
    } else {
      return res
    }
  },
  error => {
    console.log('err' + error) // for debug
    Message({
      message: error.message,
      type: 'error',
      duration: 5 * 1000
    })
    return Promise.reject(error)
  }
)

export default service

import fetch from '@/utils/request'

export function getBookNum() {
  return fetch({
    url: '/api/book/getBookPublishYearNum',
    method: 'get'
  })
}

<script>
import {
  getBookNum
} from '@/api/book/index'
export default {
  name: 'HelloWorld',
  data () {
    return {
      msg: 'Welcome to Your Vue.js App'
    }
  },
  created() {
    getBookNum().then(data => {
        console.log(data)
    })
  },
}
</script>