Vue声明式导航与编程式导航及导航守卫和axios拦截器全面详细讲解

<template>
<div>
 <h3>Home 组件</h3>
 <button @click="gotoMovie">跳转到 Movie 页面</button>
</div>
</template>
<script>
export default {
  name: "",
  methods:{
    gotoMovie(){
      this.$router.push('/movie/1')
    }
  }
}
</script>

<template>
<div>
 <h3>Home 组件</h3>
 <button @click="goBack">退回上一页</button>
</div>
</template>
<script>
export default {
  props:['id'],
  methods:{
    goBack(){
      this.$router.go(-1)
    }
  }
}
</script>

//App.vue
<template>
  <div>
    <h2>{{ info }}</h2>
    <div>
      <label>
        账号：<input type="text" v-model.trim="userName" />
      </label>
      <br /><br />
      <label>
        密码：<input type="password" v-model.trim="passWord" />
      </label>
      <br /><br />
      <button type="button" @click="login">登录</button>
    </div>
  </div>
</template>
<script type="text/javascript">
import $http from '../axios/index'
export default {
  name: "Login",
  data() {
    return {
      info: '',
      userName: '',
      passWord: '',
    }
  },
  methods: {
    login() {
      //   //对登陆信息进行验证（实际中在此处进行ajax的请求）
      //   if('lisi' === this.userName && '1234' === this.passWord){
      //     sessionStorage.setItem('isAuth',true) //在页面缓存中保存isAuth,isAuth=true表示用户已登录
      //     this.info = ''
 
      //     //判断当前路由对象中参数是否有参数
      //     if(this.$route.query.redirect){
      //       let redirect =this.$route.query.redirect
      //       this.$router.replace(redirect)//跳转到指定页面
      //     }
      //     else{
      //       this.$router.replace('/')//若路由对象中没有redirect，则直接跳转到默认的首页
      //     }
      //   }else{//非法用户
      //   sessionStorage.setItem('isAuth',false)
      //   this.userName = ''
      //   this.passWord = ''
      //   this.info = '用户名或密码错误'
      // }
      $http.post('/test/login', {
        userName: this.userName,
        passWord: this.passWord
      }).then(res => {
        if (res.data.code == 200) {
          sessionStorage.setItem('auth', res.data.tokenInfo)
          this.info = ''
          //判断当前路由对象中参数是否有参数
          if (this.$route.query.redirect) {
            let redirect = this.$route.query.redirect
            this.$router.replace(redirect)//跳转到指定页面
          }
          else {
            this.$router.replace('/')//若路由对象中没有redirect，则直接跳转到默认的首页
          }
        } else {
          sessionStorage.setItem('auth', '')
          this.userName = ''
          this.passWord = ''
          this.info = '用户名或密码错误'
        }
      })
    }
  }
}
</script>
<style scoped>
</style>

//router/insex.js
//注册全局前置导航守卫
router.beforeEach((to, from, next) => {
    //判断目标路由是否是/login,如果是，则直接调用next()方法
    if (to.path == '/login') {
        next()
    } else {//否则判断用户是否已经登录,注意这里是字符串判断
        if (sessionStorage.getItem('auth')!='' && sessionStorage.getItem('auth'!=null)) {
            next()
        } else {//如果用户访问的是受保护的资源，且没有登录，则跳转到登录页面
            //并将当前路由的完整路径作为查询参数传递给Login组件，以便登录成功后返回先前的页面
            next({//强制跳转到登录页面
                path: '/login',
                query:{ redirect:to.fullPath}
            }
            )
        }
    }
})

//前端/App.vue
<template>
  <div id="app">
    <img alt="Vue logo" src="./assets/logo.png">
  <br/>  <br/>
  <button @click="login">登录</button>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
  <button @click="test">测试拦截器</button>
  </div>
</template>
<script>
import $http from './axios/index'
export default {
  name: 'App',
  methods:{
    login(){
      $http.post('/users/login',{
        userName:'lisi',
        userPwd:'12345'
      }).then(res=>{
        if(res.data.code == 200){
          sessionStorage.setItem('Auth',res.data.mytoken)
        }
      }).catch(err=>{
        console.log(err);
      })
    },
    test(){
      $http.post('/users/test').then(res=>{
        console.log(res.data);
      }).catch(err=>{
        console.log(err);
      })
    }
  }
}
</script>

//前端/index.js
import axios from "axios";
//1. 创建axios的实例，配置基础路径
const axiosInstance = axios.create({
    baseURL: 'http://localhost:8089',
    timeout: 5000
})
//2. 定义请求拦截器:给所有请求都带上token
axiosInstance.interceptors.request.use((req) => {
    let token = sessionStorage.getItem('Auth') //获取页面存储中的token信息
    if (token) { //若token存在
        req.headers['Auth'] = token
    }
    return req;
}, (err) => {
    return Promise.reject(err)
})
// 3.响应拦截器：对服务器响应给客户端的数据进行统一的处理
axiosInstance.interceptors.response.use((res) => {
    //1.对响应数据进行处理
    let result = res.data
    let code = result.code
    if (code == 200) {
        return result
    } else {
        return Promise.reject(result)
    }
}, (err) => {
    return Promise.reject(err)
})
export default axiosInstance

//后台/usrs.js
var express = require('express');
var router = express.Router();
var jwt = require('jsonwebtoken')
/* http://localhost:8089/users/login */
router.post('/login', (req, res)=>{
  //1.接收客户的请求数据
  let user = {
    name:req.body.userName,
    pwd:req.body.userPwd
  }
  //2.定义密钥
  let temp = 'baihualin'
  //3.生成token
  let token = jwt.sign(user,temp)
  res.json({
    code:200,
    mytoken:token
  })
} );
/* http://localhost:8089/users/login */
router.post('/test',(req,res)=>{
  //输出请求头信息
  console.log(req,headers)
  let arr = [
    {
      bookId:1001,
      bookName:'Vue2从入门到精通',
      publish:'清华大学出版社'
    }, 
    {
      bookId:1002,
      bookName:'Html从入门到放弃',
      publish:'清华大学出版社'
    }, 
    {
      bookId:1003,
      bookName:'Css都是浮云',
      publish:'清华大学出版社'
    }, 
  ]
  res.json(arr)
})
module.exports = router;