A REST API for a ticket reservation system built with Java 17 and Spring Boot 3.2.

• Java 17 or higher
• Gradle 8.5 or higher (not required if using Gradle Wrapper)
• Docker & Docker Compose (for DevContainer development)

The recommended way to develop is using VS Code DevContainers with Docker Compose. This provides:

• PostgreSQL 15 database
• Redis 7 for caching
• Pre-configured Java development environment

1. Open the project in VS Code
2. Click "Reopen in Container" when prompted (or use Command Palette: "Dev Containers: Reopen in Container")
3. Run the application:

   ./gradlew bootRun

The docker profile is automatically activated in DevContainer.

For local testing without Docker:

./gradlew bootRun --args='--spring.profiles.active=test'

The application will start at http://localhost:8080.

H2 Database Console: http://localhost:8080/h2-console

• JDBC URL: jdbc:h2:mem:ticketdb
• Username: sa
• Password: (leave empty)

When using DevContainer, the following services are started:

curl -X POST http://localhost:8080/api/events \
  -H "Content-Type: application/json" \
  -d '{
    "name": "Summer Concert 2024",
    "description": "Outdoor summer concert",
    "venue": "Tokyo Dome",
    "eventDate": "2024-08-15T18:00:00",
    "totalSeats": 500,
    "price": 8000
  }'

curl http://localhost:8080/api/events

curl -X POST http://localhost:8080/api/events/1/tickets \
  -H "Content-Type: application/json" \
  -d '{
    "customerName": "John Doe",
    "customerEmail": "[email protected]",
    "numberOfSeats": 2
  }'

This endpoint uses pessimistic locking to prevent overbooking when multiple concurrent requests are made.

curl http://localhost:8080/api/tickets/code/TKT-XXXXXXXX

curl -X PATCH http://localhost:8080/api/tickets/1/cancel

In the docker profile, Redis caching is enabled for improved performance:

• Events: Cached on read, invalidated on create/update/delete
• Tickets: Not cached (ticket creation/cancellation invalidates related event cache)

Cache is disabled in test and ci profiles for simpler testing.

Health check endpoint provided by Spring Boot Actuator:

curl http://localhost:8080/actuator/health

./gradlew build

The executable JAR file will be generated at build/libs/ticket-reservation-api-0.0.1-SNAPSHOT.jar.

java -jar build/libs/ticket-reservation-api-0.0.1-SNAPSHOT.jar

./gradlew test

JMeter is used to verify that pessimistic locking prevents overbooking under concurrent load.

• JMeter 5.6.3 or higher

1. Start the application with test or ci profile (uses H2 database):

   ./gradlew bootRun --args='--spring.profiles.active=test'

2. Run JMeter test (in another terminal):

   jmeter -n -t jmeter/ticket_booking_load_test.jmx -l results.jtl

The test creates an event with 10 seats and sends 20 concurrent booking requests. With pessimistic locking, exactly 10 bookings succeed and 10 fail with "No seats available".

Note: CI/CD uses the ci profile which automatically disables Redis caching.

# Check format
./gradlew spotlessCheck

# Apply format
./gradlew spotlessApply

./gradlew checkstyleMain checkstyleTest

GitHub Actions workflow runs on push/PR to main:

1. lint: Code format check (Spotless) and static analysis (Checkstyle)
2. test: Unit and integration tests
3. build: Build application JAR
4. load-test: JMeter load test to verify no overbooking