Polling App - Full Stack Polls Application

A full-stack polling application similar to Twitter polls, built with React, Spring Boot, Spring Security, JWT authentication, and PostgreSQL.

Live Demo

Production URL: https://polling-app-z854.onrender.com

The app is hosted on Render's free tier. The first request may take about 30 seconds if the service has spun down due to inactivity.

Screenshots

Login Page	Create Poll

Voting Page	Dashboard

Architecture

Browser
  |
  | REST API (JSON)
  v
React single-page app served by Spring Boot
  |
  v
Spring MVC controllers
  |
  v
Spring Security + JWT authentication
  |
  v
Spring Data JPA repositories
  |
  v
PostgreSQL

Tech Stack

Layer	Technology
Frontend	React 16, Ant Design 3, React Router 4
Backend	Spring Boot 2.7.18, Spring MVC, Spring Data JPA
Security	Spring Security, JWT
Database	PostgreSQL
Build Tools	Maven, npm
Deployment	Render Blueprint, Docker multi-stage build

Features

• User signup and login with JWT-based authentication
• Poll creation with up to 6 choices and configurable expiration
• Voting on active polls, limited to one vote per user per poll
• Poll result percentages with visual progress bars
• User profiles with created polls and voting history
• Paginated poll lists with "Load More"
• USER and ADMIN roles initialized automatically on startup
• Responsive layout for desktop and mobile browsers

Project Structure

Polling-App/
|-- polling-app-client/          React frontend
|   |-- public/                  Static template assets
|   `-- src/
|       |-- app/                 App component and routing
|       |-- common/              Shared components
|       |-- constants/           App constants and API config
|       |-- poll/                Poll UI components
|       |-- user/                Login, signup, and profile views
|       `-- util/                API utilities and helpers
|
|-- polling-app-server/          Spring Boot backend
|   `-- src/main/java/com/example/polls/
|       |-- config/              Security and MVC configuration
|       |-- controller/          REST API controllers
|       |-- exception/           Application exceptions
|       |-- model/               JPA entities
|       |-- payload/             Request and response DTOs
|       |-- repository/          Spring Data repositories
|       |-- security/            JWT and authentication components
|       |-- service/             Business logic
|       `-- util/                Utility classes
|
|-- Dockerfile                   Multi-stage production image
|-- render.yaml                  Render Blueprint
`-- Readme.md

API Endpoints

Method	Endpoint	Description	Auth
POST	/api/auth/signin	Login	No
POST	/api/auth/signup	Register	No
GET	/api/polls	Get all polls	No
POST	/api/polls	Create a poll	Yes
POST	/api/polls/{pollId}/votes	Cast a vote	Yes
GET	/api/user/me	Get current user	Yes
GET	/api/users/{username}	Get user profile	No
GET	/api/users/{username}/polls	Get a user's polls	No
GET	/api/users/{username}/votes	Get a user's votes	No
GET	/api/user/checkUsernameAvailability	Check username availability	No
GET	/api/user/checkEmailAvailability	Check email availability	No

Local Development

Prerequisites

• Java 11 or newer
• Maven 3.6 or newer
• Node.js 14
• PostgreSQL 12 or newer

1. Clone the repository

git clone https://github.com/Vishnusige/Polling-App.git
cd Polling-App

2. Create the database

CREATE DATABASE polling_app;

3. Configure environment variables

Set these values before starting the backend:

export DB_HOST=localhost
export DB_PORT=5432
export DB_NAME=polling_app
export DB_USERNAME=postgres
export DB_PASSWORD=postgres
export JWT_SECRET=replace-with-a-long-random-secret

For Windows PowerShell:

$env:DB_HOST="localhost"
$env:DB_PORT="5432"
$env:DB_NAME="polling_app"
$env:DB_USERNAME="postgres"
$env:DB_PASSWORD="postgres"
$env:JWT_SECRET="replace-with-a-long-random-secret"

4. Run the backend

cd polling-app-server
mvn spring-boot:run

The backend starts on http://localhost:5000. Default roles (ROLE_USER and ROLE_ADMIN) are inserted automatically on startup.

5. Run the frontend

cd polling-app-client
npm install
npm start

The development client starts on http://localhost:3000.

Docker

Build and run the production image:

docker build -t polling-app .
docker run -p 5000:5000 \
  -e DB_HOST=your-db-host \
  -e DB_PORT=5432 \
  -e DB_NAME=polling_app \
  -e DB_USERNAME=postgres \
  -e DB_PASSWORD=replace-with-db-password \
  -e JWT_SECRET=replace-with-a-long-random-secret \
  polling-app

Deployment on Render

This app is configured for Render Blueprint deployment using render.yaml.

1. Fork or connect this repository in Render.
2. Create a new Blueprint from the repository and select the deployment branch.
3. Render provisions a Docker web service and a PostgreSQL database.
4. Database environment variables are wired from the managed PostgreSQL service.
5. JWT_SECRET is generated by Render.
6. The deployed app is available at https://polling-app-z854.onrender.com.

Production Notes

• The frontend is built into Spring Boot static resources during the Docker build.
• The backend serves the React app and API from the same origin.
• PostgreSQL schema management uses Hibernate ddl-auto=update.
• Role initialization is handled by polling-app-server/src/main/resources/data.sql.
• Sensitive values are supplied through environment variables.

License

This project is open source and available under the MIT License.