如何将react中的jwt令牌重定向到身份验证登录？

npm install react-router-dom axios

import React, { useState } from 'react';
import axios from 'axios';

const Login = () => {
  const [username, setUsername] = useState('');
  const [password, setPassword] = useState('');

  const handleSubmit = async (e) => {
    e.preventDefault();

    try {
      const response = await axios.post('/api/login', { username, password });
      const token = response.data.token;

      // 将JWT令牌保存到本地存储或Cookie中
      localStorage.setItem('token', token);

      // 重定向到受保护的页面
      window.location.href = '/protected';
    } catch (error) {
      console.error(error);
    }
  };

  return (
    <div>
      <h2>Login</h2>
      <form onSubmit={handleSubmit}>
        <input
          type="text"
          placeholder="Username"
          value={username}
          onChange={(e) => setUsername(e.target.value)}
        />
        <input
          type="password"
          placeholder="Password"
          value={password}
          onChange={(e) => setPassword(e.target.value)}
        />
        <button type="submit">Login</button>
      </form>
    </div>
  );
};

export default Login;

import React from 'react';
import { BrowserRouter as Router, Switch, Route } from 'react-router-dom';
import Login from './Login';
import ProtectedPage from './ProtectedPage';

const App = () => {
  return (
    <Router>
      <Switch>
        <Route path="/login" component={Login} />
        <Route path="/protected" component={ProtectedPage} />
      </Switch>
    </Router>
  );
};

export default App;

import React, { useEffect } from 'react';

const ProtectedPage = () => {
  useEffect(() => {
    const token = localStorage.getItem('token');

    if (!token) {
      // 重定向到登录页面
      window.location.href = '/login';
    }
  }, []);

  return (
    <div>
      <h2>Protected Page</h2>
      <p>This page can only be accessed after authentication.</p>
    </div>
  );
};

export default ProtectedPage;