What is JHipster Lite?

JHipster Lite is an application generator that generates step-by-step only what you need for a modern web application and/or microservice architecture. As you might imagine from the name, JHipster Lite is a different approach to application generation than its predecessor, JHipster.

Unlike JHipster, a front-end only or back-end only application can be generated. (JHipster does support just generating microservices) No questions are asked during generation; you decide which components you want as part of the generation process.

JHipster Lite does not currently generate entities or CRUD pages for the front-end. The idea is to set you up with a relatively blank slate with some initial structure. This provides a good starting pattern that can be followed as the application grows.

JHipster Lite also generates code that follows a Hexagonal Architecture. This helps with designing a system around the business intent.

Let’s Build a React App

Run JHipster Lite locally, if you want

You can certainly go straight to the JHipster Lite website and start generating there. But you can also run it locally if you have Docker. (or in my case, Rancher)

This is the command I used to run JHipster Lite locally:

docker run --rm --pull=always -p 7471:7471 -v $(pwd):/tmp/jhlite:Z -it jhipster/jhipster-lite:v0.20.0

You can also pick the latest image but I used v0.20.0 for this if you want to follow along.

If you are running locally, go to http://localhost:7471 to get to the generation UI.

Generate the initial app

For this example, let’s build a React application with a REST service running on the backend. Let’s use JWT basic authentication for security. For the REST service, we can use the dummy-feature module.

Go to the /landscape page to start selecting modules for the generated app.
If you select dummy-feature, several modules will be highlighted in red.
Select spring-boot-tomcat, springdoc-mvc-openapi and spring-boot-cucumber-jwt-authentication to enable the dummy-feature.
You can change the Properties on the right-hand side to customize the naming and other parameters.
You should now have 11 modules selected (including the dummy-feature). Go ahead and add them by pressing the Apply New (11) button.
Add basic auth by selecting spring-boot-jwt-basic-auth then press the Apply New (2) button.
Add React with JWT support by selecting react-jwt and then press the Apply New (3) button.
For convenience, add the front-end maven plugin by selecting frontend-maven-plugin and press the Apply New (1) button.
You should now have 17 modules added and can press the Download button to get the generated application.
Unzip the application in an empty directory and you are ready to customize!

Run the application and check out the dummy-service

You can run the application from your new directory by running ./mvnw if you are on a mac/linux machine. You may need to give the file executable permissions. If you already have maven installed, you can run mvn.

The base application will be available at http://localhost:8080 (using the port you chose during generation)

If you go to http://localhost:8080/swagger-ui/index.html you can see that the dummy-feature service is called Beers. A GET, POST and DELETE action was generated. A beer is shown to include an id, name and unitPrice.

Add a Beers function in React

In order to call the Beers service, we first need an interface that matches the attributes of a beer in the service.

Create a folder under src/main/webapp/app called beers.

Create a file in the beers folder called interface.d.ts

export type BeersFunctionType = {
   setBeers: Dispatch<Array<IBeer>>;
};
 export interface IBeer {
   id: string;
   name: string;
   unitPrice: string;
};

Once you have an interface, you can create a file called beers.ts in a folder under beers called services

import axios from 'axios';
 
import { getLocalStorage } from '@/common/services/storage';
import { BeersFunctionType } from '@/beers/interface';
 
const BEERS_URL = '/api/beers';
 
export const getBeers = ({ setBeers }: BeersFunctionType) => {
 const headers = {
   'Authorization': 'Bearer ' + getLocalStorage('token')
 }
  return axios
   .get(BEERS_URL, {
     headers: headers
   })
   .then(response => {
     setBeers(response.data.beers);
   })
   .catch(error => {
     console.error(error);
   });
};

In the authentication code in the generated project, the JWT is stored in local storage during login. We then place this token in the header, in order to make the service call. The response from the service is returned in an array of beer objects.

Display the results of a Beers service call

Create a beers.tsx file to output the results

import { useState, useEffect } from 'react';
import { getBeers } from '@/beers/services/beers';
import { IBeer } from '@/beers/interface';
 
export default function Beers() {
   const [beers, setBeers] = useState<Array<IBeer>>([]);
 
   useEffect(() => {getBeers({setBeers})}, []);
 
   return (
     <h2>Beers</h2>
     <ul>
        {beers.length > 0 && beers.map(beer => (<li>{beer.name}: ${beer.unitPrice}</li>))}
     </ul>
   );
}

The code here makes the call to the getBeers function and displays the beer names and prices in an unordered list.

Add a router and a route to the new beers page

Run npm install react-router-dom to install a router

To add the route, modify the src/main/webapp/app/index.tsx file like the following

import React from 'react';
import { createRoot } from 'react-dom/client';
import './index.css';
import App from '@/common/primary/app/App';
import { BrowserRouter, Routes, Route } from 'react-router-dom';
import Beers from "./beers/beers"
 
const container = document.getElementById('root');
const root = createRoot(container!);
root.render(
 <React.StrictMode>
   <BrowserRouter>
     <Routes>
       <Route path="/" element={<App />} />
       <Route path="/beers" element={<Beers />} />
     </Routes>
   </BrowserRouter>
 </React.StrictMode>
);

The imports are new and now we have a route for the home page and the new beers page.

Modify the home page to add a link to the new beers page

The home page is located at src/main/webapp/app/common/primary/app/App.tsx

Add a Link import for the react router

import { Link } from "react-router-dom";

Add a link to the new beers page

<Link to="/beers">I love beer</Link>

Add some beers with the service for display

Restart your application to make sure you have the latest changes

First, you need a JWT

curl -X 'POST' 'http://localhost:8080/api/authenticate' -H 'accept: */*' -H 'Content-Type: application/json' -d '{"username": "admin", "password": "admin", "rememberMe": true}'

Make a call to add a few different beers (this is an example) and use the token retrieved above

curl -X 'POST' 'http://localhost:8080/api/beers' -H 'accept: */*' -H 'Content-Type: application/json' -H 'Authorization: Bearer <insert token here>' -d '{"name": "pilsner", "unitPrice": 6}'

See it in action

Go to http://localhost:8080

Either click the I love beer link or go to http://localhost:8080/beers and you should see the list of beers you added

And you are done! Congrats on creating a quick React app with JHipster Lite.

Now Let’s Build an Angular App

Generate the initial app

Follow the instructions above to access JHipster Lite (http://localhost:7471 if running locally)

Follow the numbered steps above except replace react-jwt with angular-jwt in Step 7

Add these files

These files follow the pattern of the generated files in the project

Create a directory for these new files: src/main/webapp/app/beers

beers.model.ts

export interface Beers {
   beers: Array<Beer>;
 }
 export interface Beer {
   id: String;
   name: String;
   unitPrice: String;
}

This contains the interface that matches the Beer objects returned from the dummy-service

beers.service.ts

import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { Observable } from 'rxjs';
 
import { Beers } from './beers.model';
 
@Injectable({ providedIn: 'root' })
export class BeersService {
 constructor(private http: HttpClient) {}
 
 getBeers(): Observable<Beers> {
   return this.http.get<Beers>('/api/beers');
 }
}

This is the service class that makes the HTTP REST call to the beers API. Notice that we do not need to manually add the JWT to the header like in React.

beers.component.ts

import { Component, OnDestroy, OnInit } from '@angular/core';
import { Subject } from 'rxjs';
import { BeersService } from './beers.service';
 
@Component({
 selector: 'jhi-beers',
 templateUrl: './beers.component.html',
 styleUrls: ['./beers.component.css'],
})
export class BeersComponent implements OnInit, OnDestroy {
 displayedColumns: string[] = ['id', 'name', 'unitPrice'];
 beers: any = [];
 
 private readonly destroy$ = new Subject<void>();
 
 constructor(private beersService: BeersService) {}
 
 ngOnInit(): void {
   this.refresh();
 }
 
 ngOnDestroy(): void {
   this.destroy$.next();
   this.destroy$.complete();
 }
 
 refresh(): void {
   this.beersService.getBeers().subscribe({
     next: data => {
       this.beers = data.beers;
     }
   });
 }
}

This component makes a call to the service and puts the beers in an object for use by the UI

beers.route.ts

import { Route } from '@angular/router';
 
import { BeersComponent } from './beers.component';
 
export const beersRoute: Route = {
 path: '',
 component: BeersComponent,
 title: 'Beers',
};

We need a beers route that references the new component

beers.module.ts

import { NgModule } from '@angular/core';
import { RouterModule } from '@angular/router';
 
import { BeersComponent } from './beers.component';
import { beersRoute } from './beers.route';
 
import { ReactiveFormsModule } from '@angular/forms';
import { CommonModule } from '@angular/common';
 
import { MatIconModule } from '@angular/material/icon';
import { MatButtonModule } from '@angular/material/button';
import { MatButtonToggleModule } from '@angular/material/button-toggle';
import { MatFormFieldModule } from '@angular/material/form-field';
import { MatInputModule } from '@angular/material/input';
import { MatCardModule } from '@angular/material/card';
import { MatDividerModule } from '@angular/material/divider';
import { MatTableModule } from '@angular/material/table';
 
@NgModule({
 imports: [
   MatIconModule,
   MatButtonModule,
   MatButtonToggleModule,
   MatFormFieldModule,
   MatInputModule,
   MatCardModule,
   MatDividerModule,
   MatTableModule,
   ReactiveFormsModule,
   CommonModule,
   RouterModule.forChild([beersRoute])
 ],
 declarations: [BeersComponent],
})
export class BeersModule {}

The beers module declares the new component and also adds a new module for a material design table

beers.component.css

mat-card {
   width: 350px;
   display: block;
   margin-left: auto;
   margin-right: auto;
   margin-top: 20px;
 }

A little style copied from the generated code

beers.component.html

<div>
   <h2>Beer is the answer</h2>
 </div>
  <table mat-table [dataSource]="beers" class="mat-elevation-z8" aria-describedby="Beers table">
   <ng-container matColumnDef="id">
     <th mat-header-cell *matHeaderCellDef>ID</th>
     <td mat-cell *matCellDef="let element">{{ element.id }}</td>
   </ng-container>
    <ng-container matColumnDef="name">
     <th mat-header-cell *matHeaderCellDef>Name</th>
     <td mat-cell *matCellDef="let element">{{ element.name }}</td>
   </ng-container>
    <ng-container matColumnDef="unitPrice">
     <th mat-header-cell *matHeaderCellDef>Unit Price</th>
     <td mat-cell *matCellDef="let element">{{ element.unitPrice }}</td>
   </ng-container>
    <tr mat-header-row *matHeaderRowDef="displayedColumns"></tr>
   <tr mat-row *matRowDef="let row; columns: displayedColumns;"></tr>
 </table>

An HTML fragment for displaying the beer data in a table

Modify these files

The app-routing.module.ts file needs to have the beers route added. The entire file should look like this:

import { NgModule } from '@angular/core';
import { RouterModule, Routes } from '@angular/router';
 
export const routes: Routes = [
 {
   path: '',
   loadChildren: () => import('./login/login.module').then(m => m.LoginModule),
 },
 {
   path: 'beers',
   loadChildren: () => import('./beers/beers.module').then(m => m.BeersModule),
 },
 
// jhipster-needle-angular-route
];
 
@NgModule({
 imports: [RouterModule.forRoot(routes)],
 exports: [RouterModule],
})
export class AppRoutingModule {}

The last step is to add a link to the home page at app.component.html

 <a routerLink="beers" routerLinkActive="active" ariaCurrentWhenActive="page">I love beer</a>

You can now restart and add some beers to the service using the steps above

See it in action

Go to http://localhost:8080

Either click the I love beer link or go to http://localhost:8080/beers and you should see the list of beers you added

Conclusion

As you can see, JHipster Lite helps you bootstrap a new application and hit the ground running. That leaves more time for the functionality and less time with boilerplate code. It can also keep you on the right track if you are just learning a front-end framework and want to work within some known best practices.

Let us know if you would like a talk or demo on JHipster Lite. Or better yet, if you need something built quickly and correctly!

How to Create a Quick React and Angular App with JHipster Lite

What is JHipster Lite?

Let’s Build a React App

Run JHipster Lite locally, if you want

Generate the initial app

Run the application and check out the dummy-service

Add a Beers function in React

Display the results of a Beers service call

Add a router and a route to the new beers page

Modify the home page to add a link to the new beers page

Add some beers with the service for display

See it in action

Now Let’s Build an Angular App

Generate the initial app

Add these files

Modify these files

See it in action

Conclusion

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