一：目录结构

比如有四个页面组件，error home index login 假定 home是要登录以后才能访问的话。怎么做呢？先上整体目录结构吧

二：路由router

1，在路由中分成 map 去做，单独拆分成路由地址：如

//routerMap.jsx


import Index from "../page/index";
import Home from "../page/home";
import ErrorPage from "../page/error";
import Login from "../page/login";
export default [
    { path: "/", name: "App", component: Index, auth: true },
    { path: "/home", name: "Home", component: Home, auth: true },
    { path: "/login", name: "Login", component: Login },
    { path: "/404", name: "404", component: ErrorPage },
];

2，把权限配置封装部分拿出来：如

//FrontendAuth.jsx
import React, { Component } from "react";
import { Route, Redirect } from "react-router-dom";
class FrontendAuth extends Component {
    // eslint-disable-next-line no-useless-constructor
    constructor(props) {
        super(props);
    }
    render() {
        const { routerConfig, location } = this.props;
        const { pathname } = location;
        const isLogin = sessionStorage.getItem("username");
        console.log(pathname, isLogin);
        console.log(location);
        // 如果该路由不用进行权限校验，登录状态下登陆页除外
        // 因为登陆后，无法跳转到登陆页
        // 这部分代码，是为了在非登陆状态下，访问不需要权限校验的路由
        const targetRouterConfig = routerConfig.find(
            (item) => item.path === pathname
        );
        console.log(targetRouterConfig);
        if (targetRouterConfig && !targetRouterConfig.auth && !isLogin) {
            const { component } = targetRouterConfig;
            return <Route exact path={pathname} component={component} />;
        }
        if (isLogin) {
            // 如果是登陆状态，想要跳转到登陆，重定向到主页
            if (pathname === "/login") {
                return <Redirect to="/" />;
            } else {
                // 如果路由合法，就跳转到相应的路由
                if (targetRouterConfig) {
                    return (
                        <Route path={pathname} component={targetRouterConfig.component} />
                    );
                } else {
                    // 如果路由不合法，重定向到 404 页面
                    return <Redirect to="/404" />;
                }
            }
        } else {
            // 非登陆状态下，当路由合法时且需要权限校验时，跳转到登陆页面，要求登陆
            if (targetRouterConfig && targetRouterConfig.auth) {
                return <Redirect to="/login" />;
            } else {
                // 非登陆状态下，路由不合法时，重定向至 404
                return <Redirect to="/404" />;
            }
        }
    }
}
export default FrontendAuth;

3，最后集合弹出：

//index/jsx

import React, { Component } from "react";
import { BrowserRouter as Router, Switch } from "react-router-dom";
import axios from '../util/axiosTool'
import * as Tool from "../util/tool"
import FrontendAuth from "./FrontendAuth";
import routerMap from "./routerMap";

React.Component.prototype.$axios = axios;
React.Component.prototype.$Tool = Tool;

class Routers extends Component {
    // eslint-disable-next-line no-useless-constructor
    constructor(props) {
        super(props);
    }
    render() {
        return (
            <Router>
                <div>
                    <Switch>
                        <FrontendAuth routerConfig={routerMap} />
                    </Switch>
                </div>
            </Router>
        );
    }
}

export default Routers;

三:页面组件

1，login

import React, { Component } from "react";
import { Redirect } from "react-router-dom"; //重定向使用
class Login extends Component {
    constructor(props) {
        super(props);
        this.state = {
            username: "",
            password: "",
            rediectToReferrer: false, // 是否重定向之前的界面
        };
        this.handleChange = this.handleChange.bind(this);
        this.handleSumit = this.handleSumit.bind(this);
    }
    // 处理用户名、密码的变化
    handleChange(e) {
        if (e.target.name === "username") {
            this.setState({
                username: e.target.value,
            });
        } else if (e.target.name === "password") {
            this.setState({
                password: e.target.value,
            });
        }
    }
    // 提交登录表单
    async handleSumit(e) {
        e.preventDefault();
        const username = this.state.username;
        const password = this.state.password;
        if (username.length === 0 || password.length === 0) {
            alert("用户名或密码不能为空！");
            return;
        }
        // 保存信息到sessionStorage
        sessionStorage.setItem("username", username);
        // 登录成功后，设置redirectToReferrer为true;
        this.setState({
            rediectToReferrer: true,
        });
        let RedirectUrl = this.props.location.state
            ? this.props.location.state.from.pathname
            : "/";
        // 登陆成功之后的跳转
        this.props.history.push(RedirectUrl);
    }
    render() {
        return (
            <form className="login" onSubmit={this.handleSumit}>
                <div>
                    <label htmlFor="">
                        用户名：
                        <input
                            type="text"
                            name="username"
                            value={this.state.username}
                            onChange={this.handleChange}
                        />
                    </label>
                </div>
                <div>
                    <label htmlFor="">
                        密码：
                        <input
                            type="password"
                            name="password"
                            value={this.state.password}
                            onChange={this.handleChange}
                        />
                    </label>
                </div>
                <input type="submit" value="登录" />
            </form>
        );
    }
}
export default Login;

登录页面视图：

即可，在没登录的时候是无法访问 home的在 map里面用 auth: true 来区分，可以结合token来一起使用。

本demo已经携带了 token 加入请求header 封装。

动图权限测试：未登录不许可访问home