🗳️ Spring Boot & Flutter Polling Application

A modern, full-stack Polling & Voting application built with a Spring Boot REST API backend and a Flutter mobile client. The application enables users to create customizable polls with dynamic options, vote in real-time, and view live percentage-based results with interactive visualizations.

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📱 App Screenshots

Live Polls & Voting

Create Dynamic Poll

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✨ Features

• Live Polls Feed: View all available community polls with question details, live vote counts, and total voter turnout badges.
• Interactive Voting: Instant voting with live progress bars, vote counts, and calculated percentages for each option.
• Dynamic Poll Creation:
  • Add or remove options dynamically with real-time UI updates.
  • Validation ensuring questions are non-empty and at least 2 valid options are provided.
• Clean Architecture & State Management:
  • Predictable unidirectional data flow powered by BLoC (flutter_bloc).
  • Robust functional programming and error handling with fpDart (Either<Failure, T>).
  • Network requests managed using Dio with centralized error interceptors and timeout configurations.
• Robust REST API Backend:
  • Spring Boot Data JPA with MySQL database persistence.
  • Standardized JSON responses via ApiResponse<T>.
  • Global exception handling and request validations.

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🛠️ Tech Stack

Mobile Frontend (Flutter)

• Framework: Flutter (Dart 3.x)
• State Management: flutter_bloc
• Networking: dio
• Functional Programming: fpdart
• Design System: Material 3 (with Light and Dark theme support)

Backend (Spring Boot)

• Language & Framework: Java 17+, Spring Boot (Spring Web MVC, Spring Data JPA)
• Database: MySQL (Hibernate ORM)
• Utilities: Project Lombok
• Build Tool: Maven

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📂 Project Structure

Spring-Boot-Polling-Application/
├── Backend/                              # Spring Boot REST API
│   ├── src/main/java/com/faizan/voting_application/
│   │   ├── controllers/                  # REST Controllers (PollController)
│   │   ├── dto/                          # Data Transfer Objects (ApiResponse, Vote)
│   │   ├── middleware/                   # GlobalExceptionHandler
│   │   ├── model/                        # JPA Entities (Poll, OptionVote)
│   │   ├── repositories/                 # Spring Data Repositories
│   │   └── services/                     # Business Logic Services
│   ├── pom.xml
│   └── src/main/resources/application.properties
│
├── flutter_voting_app/                   # Flutter Mobile Application
│   ├── lib/
│   │   ├── core/
│   │   │   ├── constants/                # API Endpoints & Base URLs
│   │   │   ├── error/                    # Failure classes for fpDart
│   │   │   └── network/                  # Dio ApiClient
│   │   ├── data/
│   │   │   ├── models/                   # PollModel, OptionVoteModel, ApiResponseModel
│   │   │   └── repositories/             # PollRepository (fpDart Either implementation)
│   │   ├── presentation/
│   │   │   ├── bloc/                     # PollListBloc & CreatePollBloc
│   │   │   ├── screens/                  # HomeScreen, CreatePollScreen
│   │   │   └── widgets/                  # PollCard, DynamicOptionInput
│   │   └── main.dart
│   └── pubspec.yaml
│
└── images/                               # Screenshots & Assets

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🔌 API Endpoints

Method	Endpoint	Description	Request Body
GET	/api/polls	Retrieve all polls	None
GET	/api/polls/{id}	Retrieve a single poll by ID	None
POST	/api/polls	Create a new poll	{ "question": "...", "options": [ { "voteOption": "...", "voteCount": 0 } ] }
POST	/api/polls/vote	Cast a vote on a poll option	{ "pollId": 1, "optionIndex": 0 }

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🚀 Getting Started

Prerequisites

• Java JDK 17+
• MySQL Server (running on port 3306)
• Flutter SDK (v3.12+ recommended)
• Android Studio / Xcode for emulators or a physical device

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1. Backend Setup

1. Configure Database: Create a MySQL database named voting_app:

   CREATE DATABASE voting_app;

2. Configure application.properties: Update /Backend/src/main/resources/application.properties with your database credentials:

   spring.datasource.url=jdbc:mysql://localhost:3306/voting_app
   spring.datasource.username=YOUR_MYSQL_USERNAME
   spring.datasource.password=YOUR_MYSQL_PASSWORD

3. Run the Backend:

   cd Backend
   ./mvnw spring-boot:run

   The backend will start on http://localhost:8080.

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2. Flutter App Setup

1. Navigate to the Flutter project:

   cd flutter_voting_app

2. Install dependencies:

   flutter pub get

3. Run the App:

   • For iOS Simulator / macOS / Web:

     flutter run

   • For Android Emulator: The app is preconfigured to route requests to http://10.0.2.2:8080.

     flutter run

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🧪 Testing

• Flutter Tests:

  cd flutter_voting_app
  flutter test

• Backend Tests:

  cd Backend
  ./mvnw test

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📄 License

This project is licensed under the MIT License - see the LICENSE file for details.