content: import React from 'react';
  import './App.css';
  import {HashRouter, Route, Switch} from 'react-router-dom'
  import BlacklistUserComponent from './components/BlacklistUserComponent';
  import ListTargetComponent from './components/ListTargetComponent';
  import HeaderComponent from './components/HeaderComponent';
  import ViewTargetComponent from './components/ViewTargetComponent';
  
  function App() {
    return (
      <div>
          <HashRouter>
                <HeaderComponent />
                  <div className="container">
                      <Switch> 
                            <Route path = "/blacklist_user" component = {BlacklistUserComponent}></Route>
                            <Route path = "/" exact component = {ListTargetComponent}></Route>
                            <Route path = "/add" component = {ViewTargetComponent}></Route>
                            <Route path = "/edit/:id" component = {ViewTargetComponent}></Route>
                      </Switch>
                  </div>
          </HashRouter>
      </div>
      
    );
  }
  
  export default App;
  