Gift Card Winner

Gift Card Winner is a Spring Boot + Spring Batch application that performs the following batch jobs:

1. User Import Job – Fetches users from an external API.
2. Order Import Job – Reads and imports order data from a CSV file.
3. Winner Selection Job – Selects a weekly gift card winner based on a configurable order amount threshold.

This application is ideal for automating data ingestion and reward logic in an e-commerce setting.

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Features

• Fetch user data from https://jsonplaceholder.typicode.com/users.
• Read order data from a CSV file.
• Persist users and orders into a relational database.
• Select a gift card winner randomly from users whose total order amount exceeds a threshold.
• Retry logic for API calls.
• Unit testing using Mockito, Spring Batch Test, and H2.
• Docker support for containerized deployment.

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Prerequisites

• Java 17+
• Maven 3.8.6+
• Docker (optional)
• Database:
  • H2 for testing (in-memory)
  • PostgreSQL or other JDBC-supported DB for production

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Project Structure

GiftCardWinner/
├── src/
│   ├── main/
│   │   ├── java/com/ecom/giftcardwinner/
│   │   │   ├── config/              # Batch configuration
│   │   │   ├── controller/          # Controller (Winner details)
│   │   │   ├── schduler/            # Job definitions
│   │   │   ├── model/               # Entity classes (User, Order)
│   │   │   ├── processor/           # Data processors
│   │   │   ├── reader/              # API and CSV readers
│   │   │   ├── repository/          # Spring Data JPA repositories
│   │   │   └── writer/              # Database writers
│   │   │   └── tasklet/             # table truncate and winner selection tasklet
│   │   └── resources/
│   │       └── application.properties
│   └── test/
│       └── java/com/ecom/giftcardwinner/
│           ├── config/
│           └── controller/
│           ├── reader/
│           ├── schduler/
│           ├── tasklet/
├── Dockerfile
├── pom.xml
└── README.md

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Setup & Installation

Local Development

1. Clone the repo

git clone https://github.com/Sugandhab/GiftCardWinner.git
cd GiftCardWinner

2. Build the project

mvn clean install

3. Configure Application As per need – Update src/main/resources/application.properties:

# ------------------------
# BATCH CONFIGURATION
# ------------------------
batch.chunk-size=10
batch.skip-limit=10
batch.sql.truncate-orders=TRUNCATE TABLE orders RESTART IDENTITY
batch.winner.eligibility.amount=20

# ------------------------
# H2 DATABASE CONFIG
# ------------------------
spring.datasource.driverClassName=org.h2.Driver
spring.datasource.password=
spring.datasource.url=jdbc:h2:mem:testdb;DB_CLOSE_DELAY=-1
spring.datasource.username=sa

spring.h2.console.enabled=true
spring.h2.console.path=/h2-console

# ------------------------
# JPA / HIBERNATE CONFIG
# ------------------------
spring.jpa.database-platform=org.hibernate.dialect.H2Dialect
spring.jpa.hibernate.ddl-auto=update
spring.jpa.properties.hibernate.format_sql=true
spring.jpa.show-sql=true

# ------------------------
# SPRING BATCH CONFIG
# ------------------------
spring.batch.job.enabled=false
spring.batch.jdbc.initialize-schema=always

# ------------------------
# SCHEDULER CONFIG
# ------------------------
# Fixed rate execution in milliseconds (e.g., every 24 hours = 86400000 ms, 7 days = 604,800,000 ms)
scheduler.fixed-rate-ms=86400000
scheduler.initial-delay-ms=10000
scheduler.run-on-startup=false

# ------------------------
# USER API CONFIG
# ------------------------
user.api.initial-backoff-ms=1000
user.api.max-retries=3
user.api.url=https://jsonplaceholder.typicode.com/users

# ------------------------
# CSV CONFIG
# ------------------------
order.csv.path=${ORDER_CSV_PATH:/app/data/order.csv}

4. Run the app

mvn spring-boot:run

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Running Tests

mvn test

• Unit tests included.
• Uses Mockito and H2.
• Debug logs can be enabled:

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Docker Usage

Build Docker Image

docker build -t giftcardwinner:latest .

Run Docker Container

docker run -p 8080:8080   -e ORDER_CSV_PATH=/app/data/order.csv   -v "$(pwd)/data:/app/data"   --name giftcardwinner giftcardwinner:latest

Stop and Remove

docker stop giftcardwinner
docker rm giftcardwinner

CSV File Mounting for Scheduled Winner Job

To ensure the job runs correctly, make sure you mount the correct CSV file containing order data into the Docker container. This file is required for the batch job to process purchases and select a winner.

• Replace $(pwd)/data/order.csv with the absolute path to your actual CSV file, if needed.
• The value of ORDER_CSV_PATH must match the target path inside the container (/app/data/order.csv).

Example Docker Run Command

docker run -p 8080:8080 \
  -e ORDER_CSV_PATH=/app/data/order.csv \
  -v "$(pwd)/data/order.csv:/app/data/order.csv" \
  --name giftcardwinner \
  giftcardwinner:latest

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Winner Selection Logic

• Orders are read from CSV.
• Users with total order amount > batch.winner.eligibility.amount are eligible.
• A winner is selected randomly in memory from the eligible users
• The winner is then persisted in the winner table along with a timestamp.

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API Endpoints

These endpoints are exposed via WinnerController for easy access winner data:

GET /api/winner/latest

• Returns the most recently selected gift card winner.
• Example response:

{
  "userId": 3,
  "name": "Clementine Bauch",
  "amount":103.34,
  "createdAt":"2025-05-12T23:05:40.372011"
}

GET /api/winner/all

• Returns list of all winners.
• Example response:

[{"userId":5,"name":"Chelsey Dietrich","amount":103.34,"createdAt":"2025-05-12T23:05:40.372011"},..]

Both endpoints run on:
http://localhost:8080/api/winner/

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