springboot 处理 前端 传递的blob springboot 前台

前言：最近不是很忙，所以抽时间学了一下使用vue-element-admin4.0结合springboot2构建一个后台管理页面。

vue-element-admin4.0国内节点访问地址：vue-element-admin

本此使用的是GitHub - PanJiaChen/vue-element-admin at i18n 国际化分支的版本。说是除了国际化其他都一样。

本文主要介绍前台动态的使用资源权限。

• 后台使用springboot2搭建项目就不说了，百度一下一大堆。
• 前台开发前需要安装一下nodejs，这里注意一下nodejs和npm的版本要相互匹配，否则在编译的时候会报错。

（为什么要说笨版本问题呢？是因为我最开始安装的是nodejs11.06的版本，npm是安装的时候自带安装的，npm版本好像6.5。我手贱使用更新软件把nodejs更新了，更新到了12.13，问题来了，打开ide项目无法启动，报错。那是因为更新nodejs的时候没有同步更新到相匹配的npm版本。哎。。。。。。。最后把npm更新到最新版。版本是6.12.1）

他们使用的是vscode开发的，我觉得不太好用，我用的是webstorm

打开项目后需要安装一下依赖的模块。

npm install 

• 1、全局请求配置的修改。

src/utils/request.js

import axios from 'axios'
// import { MessageBox, Message } from 'element-ui'
import { MessageBox, Message } from 'element-ui'
import store from '@/store'
import { getToken, removeToken } from '@/utils/auth'

const qs = require('querystring')

// 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: 5000, // request timeout
  jsonData: false
})

// request interceptor
service.interceptors.request.use(
  config => {
    if (store.getters.token) {
      // let each request carry token
      // ['X-Token'] is a custom headers key
      // please modify it according to the actual situation
      config.headers['X-Token'] = getToken()
    }

    if (config.method.toLowerCase() === 'get') {
      config.params = config.data
    } else if (config.method.toLowerCase() === 'post') {
      if (config.jsonData) {
        config.headers['Content-Type'] = 'application/json;charset=UTF-8'
        config.data = JSON.stringify(config.data)
      } else {
        config.headers['Content-Type'] = 'application/x-www-form-urlencoded;charset=UTF-8'
        config.data = qs.stringify(config.data)
      }
    }
    // console.log(config) // for debug
    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.data
    // code==2000是业务逻辑成功，其他的返回code都是业务逻辑错误
    if (res.code === 5002) {
      // to re-login
      // token过期或者密码被修改了都需要重新获取token
      MessageBox.confirm('You have been logged out, you can cancel to stay on this page, or log in again', 'Confirm logout', {
        confirmButtonText: 'Re-Login',
        cancelButtonText: 'Cancel',
        type: 'warning'
      }).then(() => {
        store.dispatch('user/resetToken').then(() => {
          location.reload()
        })
      })
    } else {
      return res
    }
  },
  error => {
    // console.log('err' + error) // for debug
    Message({
      message: error.message,
      type: 'error',
      duration: 5 * 1000
    })
    removeToken()
    if (error.response && error.response.status === 403) {
      this.$router.push(`/login?redirect=${this.$route.fullPath}`)
    }
    return Promise.reject(error)
  }
)

export default service

这个文件修改的主要是get、post请求传递参数的设置。

get使用params传递参数。post就data

axios默认请求是json传递参数，但是我的项目中一些简单参数我还是希望是亿form的形式传递过去。后台接受参数时候比较简单。

所以我添加了一个jsonData的标识在请求方法中，根据这个标识来判断传递的是json还是普通的form数据。

还有就是form数据需要转化，使用qs.stringify来转换。转化成A=1&B=2&c=3这样的形式。

• 2、后台接口路径的配置。

 我是本地开发环境，所以直接配置的是：VUE_APP_BASE_API = 'http://localhost:8088'

• 登录设置角色信息、过滤路由（根据角色动态的生成菜单）
• store/user.js

import { loginByPwd, logout, getLoginUserInfo } from '@/api/user'
import { getToken, setToken, removeToken } from '@/utils/auth'
import router, { resetRouter } from '@/router'

const state = {
  token: getToken(),
  name: '',
  avatar: '',
  introduction: '',
  roles: []
}

const mutations = {
  SET_TOKEN: (state, token) => {
    state.token = token
  },
  SET_INTRODUCTION: (state, introduction) => {
    state.introduction = introduction
  },
  SET_NAME: (state, name) => {
    state.name = name
  },
  SET_AVATAR: (state, avatar) => {
    state.avatar = avatar
  },
  SET_ROLES: (state, roles) => {
    state.roles = roles
  }
}

const actions = {
  // user login
  loginByPwd({ commit }, userInfo) {
    const { userName, passWord } = userInfo

    return new Promise((resolve, reject) => {
      loginByPwd({ userName: userName.trim(), passWord: passWord }).then(response => {
        if (response.code === 2000) {
          commit('SET_TOKEN', response.data)
          setToken(response.data)
        }
        resolve(response)
      }).catch(error => {
        reject(error)
      })
    })
  },

  // get user info
  getLoginUserInfo({ commit, state }) {
    return new Promise((resolve, reject) => {
      getLoginUserInfo(state.token).then(response => {
        // const { data } = response

        // console.log('getLoginUserInfo', response)

        if (!response) {
          reject('Verification failed, please Login again.')
        }

        if (response.resultFlag) {
          commit('SET_ROLES', response.data.roleList)
          commit('SET_NAME', response.data.likeName)
          commit('SET_AVATAR', response.data.imgUrl)
          commit('SET_INTRODUCTION', '我是一个超级管理员哦')
          // 一个用户可能有多个角色，这里返回的是角色的集合信息
          // let allRole = response.data.roleList

          resolve(response)
        } else {
          console.error('获取当前登录用户信息出错了')
        }
      }).catch(error => {
        reject(error)
      })
    })
  },

  // user logout
  logout({ commit, state }) {
    return new Promise((resolve, reject) => {
      logout(state.token).then(() => {
        commit('SET_TOKEN', '')
        commit('SET_ROLES', [])
        removeToken()
        resetRouter()
        resolve()
        location.reload()
      }).catch(error => {
        reject(error)
      })
    })
  },

  // remove token
  resetToken({ commit }) {
    return new Promise(resolve => {
      commit('SET_TOKEN', '')
      commit('SET_ROLES', [])
      removeToken()
      resolve()
    })
  },

  // dynamically modify permissions
  changeRoles({ commit, dispatch }, role) {
    return new Promise(async resolve => {
      const token = role + '-token'

      commit('SET_TOKEN', token)
      setToken(token)

      const { roles } = await dispatch('getInfo')

      resetRouter()

      // generate accessible routes map based on roles
      const accessRoutes = await dispatch('permission/generateRoutes', roles, { root: true })

      // dynamically add accessible routes
      router.addRoutes(accessRoutes)

      // reset visited views and cached views
      dispatch('tagsView/delAllViews', null, { root: true })

      resolve()
    })
  }
}

export default {
  // namespaced: true,
  state,
  mutations,
  actions
}

这个文件就是登录，成功后获取当前用户拥有的资源信息。

系统中或者说网络上现在都是直接使用roles来做的判断，就是在router.js文件中直接把菜单需要的角色设置在里边。

缺点是添加了角色就要修改代码打包发布。这简直是灾难。

response.data.roleList 就是用户拥有的角色信息，我这里还是多角色。把角色信息放在全局缓存里边。

• src/permission.js 

这个文件在打开每个菜单的时候都会去执行以下，检查你的权限信息

检查的时候，把java后台返回的角色资源合并了一下，因为我使用的是多角色，拥有的菜单可能有重复的，这个是最烦人的，因为拥有的资源菜单是多维数组，在判断的时候需要和本地前台的系统路由进行相互判断。

• src/store/modules/permission.js

可以看到我用系统提供的深度克隆把系统的动态路由克隆了一份，为什么要这样呢，因为我们不能改变系统本地的动态路由，如果你有权限新建角色，如果你改变了系统的路由，那你建的角色岂不是很多菜单都没办法选择。所以我深度克隆了一个全局的动态路由来操作，也不会改变原来的路由。

import { asyncRoutes, constantRoutes } from '@/router'

asyncRoutes是系统中定义的动态路由，需要做权限验证在左边菜单栏显示的都在这个对象里边设置

看到系统默认使用roles来做权限验证的，但是没办法和后台互动起来啊。

重点来了：

我花了很久才搞定这里，这是我目前想到的办法。

/**
 *
 * @param  {Array} userRouters 后台返回的用户权限json
 * @param  {Array} allRouter  前端配置好的所有动态路由的集合
 * @return {Array} realRoutes 过滤后的路由
 */
function recursionRouter(userRouters = [], allRouter = []) {
  const realRoutes = []
  allRouter.forEach(sysRoute => {
    if (sysRoute.meta) {
      if (sysRoute.flag === undefined) {
        sysRoute.flag = true
      }
      userRouters.forEach(item => {
        if (item.meta && item.meta.title === sysRoute.meta.title) {
          if (item.children && item.children.length > 0) {
            sysRoute.children.concat(recursionRouter(item.children, sysRoute.children))
          }
          if (sysRoute.flag) {
            realRoutes.push(sysRoute)
            sysRoute.flag = false
          }
        }
      })
      if (sysRoute.children) {
        sysRoute.children = sysRoute.children.filter(a => a.flag === false)
      }
    } else {
      realRoutes.push(sysRoute)
    }
  })
  return realRoutes
}

就是把克隆的路由和后台返回的路由信息进行比对，最终得到一个本登录用户拥有的资源信息数组，多维数组哦。。。

这是我目前写的代码，js好坑的 return true都没办法退出函数拿来判断。

以上代码就是本文的精华。

如果有哪位有更简洁的更有效的方法，请回复，非常感谢。

还漏了一个系统添加角色：

还是系统中的添加角色方法。

这里把选择的资源的component属性删除了，太大了，而且没有必要保存在数据库中。

超级管理员添加到数据库中的资源信息：

[{"path":"/permission","redirect":"/permission/page","alwaysShow":true,"name":"Permission","meta":{"title":"permission","icon":"lock","roles":["admin","editor"]},"children":[{"path":"page","name":"PagePermission","meta":{"title":"pagePermission","roles":["admin"]}},{"path":"directive","name":"DirectivePermission","meta":{"title":"directivePermission"}},{"path":"role","name":"RolePermission","meta":{"title":"rolePermission","roles":["admin"]}}],"flag":true},{"path":"/icon","children":[{"path":"/icon/index","name":"Icons","meta":{"title":"icons","icon":"icon","noCache":true}}],"flag":true},{"path":"/components","redirect":"noRedirect","name":"ComponentDemo","meta":{"title":"components","icon":"component"},"children":[{"path":"tinymce","name":"TinymceDemo","meta":{"title":"tinymce"}},{"path":"markdown","name":"MarkdownDemo","meta":{"title":"markdown"}},{"path":"json-editor","name":"JsonEditorDemo","meta":{"title":"jsonEditor"}},{"path":"split-pane","name":"SplitpaneDemo","meta":{"title":"splitPane"}},{"path":"avatar-upload","name":"AvatarUploadDemo","meta":{"title":"avatarUpload"}},{"path":"dropzone","name":"DropzoneDemo","meta":{"title":"dropzone"}},{"path":"sticky","name":"StickyDemo","meta":{"title":"sticky"}},{"path":"count-to","name":"CountToDemo","meta":{"title":"countTo"}},{"path":"mixin","name":"ComponentMixinDemo","meta":{"title":"componentMixin"}},{"path":"back-to-top","name":"BackToTopDemo","meta":{"title":"backToTop"}},{"path":"drag-dialog","name":"DragDialogDemo","meta":{"title":"dragDialog"}},{"path":"drag-select","name":"DragSelectDemo","meta":{"title":"dragSelect"}},{"path":"dnd-list","name":"DndListDemo","meta":{"title":"dndList"}},{"path":"drag-kanban","name":"DragKanbanDemo","meta":{"title":"dragKanban"}}],"flag":true},{"path":"/charts","redirect":"noRedirect","name":"Charts","meta":{"title":"charts","icon":"chart"},"children":[{"path":"keyboard","name":"KeyboardChart","meta":{"title":"keyboardChart","noCache":true}},{"path":"line","name":"LineChart","meta":{"title":"lineChart","noCache":true}},{"path":"mix-chart","name":"MixChart","meta":{"title":"mixChart","noCache":true}}],"flag":true},{"path":"/nested","redirect":"/nested/menu1/menu1-1","name":"Nested","meta":{"title":"nested","icon":"nested"},"children":[{"path":"menu1","name":"Menu1","meta":{"title":"menu1"},"redirect":"/nested/menu1/menu1-1","children":[{"path":"menu1-1","name":"Menu1-1","meta":{"title":"menu1-1"}},{"path":"menu1-2","name":"Menu1-2","redirect":"/nested/menu1/menu1-2/menu1-2-1","meta":{"title":"menu1-2"},"children":[{"path":"menu1-2-1","name":"Menu1-2-1","meta":{"title":"menu1-2-1"}},{"path":"menu1-2-2","name":"Menu1-2-2","meta":{"title":"menu1-2-2"}}]},{"path":"menu1-3","name":"Menu1-3","meta":{"title":"menu1-3"}}]},{"path":"menu2","name":"Menu2","meta":{"title":"menu2"}}],"flag":true},{"path":"/table","redirect":"/table/complex-table","name":"Table","meta":{"title":"Table","icon":"table"},"children":[{"path":"dynamic-table","name":"DynamicTable","meta":{"title":"dynamicTable"}},{"path":"drag-table","name":"DragTable","meta":{"title":"dragTable"}},{"path":"inline-edit-table","name":"InlineEditTable","meta":{"title":"inlineEditTable"}},{"path":"complex-table","name":"ComplexTable","meta":{"title":"complexTable"}}],"flag":true},{"path":"/example","redirect":"/example/list","name":"Example","meta":{"title":"example","icon":"example"},"children":[{"path":"create","name":"CreateArticle","meta":{"title":"createArticle","icon":"edit"}},{"path":"list","name":"ArticleList","meta":{"title":"articleList","icon":"list"}}],"flag":true},{"path":"/tab","children":[{"path":"/tab/index","name":"Tab","meta":{"title":"tab","icon":"tab"}}],"flag":true},{"path":"/error","redirect":"noRedirect","name":"ErrorPages","meta":{"title":"errorPages","icon":"404"},"children":[{"path":"401","name":"Page401","meta":{"title":"page401","noCache":true}},{"path":"404","name":"Page404","meta":{"title":"page404","noCache":true}}],"flag":true},{"path":"/error-log","children":[{"path":"/error-log/log","name":"ErrorLog","meta":{"title":"errorLog","icon":"bug"}}],"flag":true},{"path":"/excel","redirect":"/excel/export-excel","name":"Excel","meta":{"title":"excel","icon":"excel"},"children":[{"path":"export-excel","name":"ExportExcel","meta":{"title":"exportExcel"}},{"path":"export-selected-excel","name":"SelectExcel","meta":{"title":"selectExcel"}},{"path":"export-merge-header","name":"MergeHeader","meta":{"title":"mergeHeader"}},{"path":"upload-excel","name":"UploadExcel","meta":{"title":"uploadExcel"}}],"flag":true},{"path":"/zip","redirect":"/zip/download","alwaysShow":true,"name":"Zip","meta":{"title":"zip","icon":"zip"},"children":[{"path":"/zip/download","name":"ExportZip","meta":{"title":"exportZip"}}],"flag":true},{"path":"/pdf","redirect":"/pdf/index","children":[{"path":"/pdf/index","name":"PDF","meta":{"title":"pdf","icon":"pdf"}}],"flag":true},{"path":"/theme","children":[{"path":"/theme/index","name":"Theme","meta":{"title":"theme","icon":"theme"}}],"flag":true},{"path":"/clipboard","children":[{"path":"/clipboard/index","name":"ClipboardDemo","meta":{"title":"clipboardDemo","icon":"clipboard"}}],"flag":true},{"path":"/i18n","children":[{"path":"/i18n/index","name":"I18n","meta":{"title":"i18n","icon":"international"}}],"flag":true},{"path":"external-link","children":[{"path":"/external-link/https:/github.com/PanJiaChen/vue-element-admin","meta":{"title":"externalLink","icon":"link"}}],"flag":true}]

可以格式化json看一下结构，除了component 其他都一样

• 注意点 
• 退出后换个用户登录，资源菜单有时候没有刷新，使用系统中的logout还是有问题。所以我在退出的时候加了强制刷新。

======================2020年1月9日18:07:00==============================

请求的jsonflag在传递的时候做了下修改，放在headers里边传递过去

相应的在判断里边也修改一下