Coffee Queue - Spring Boot Application

A simple Spring Boot application that simulates an office coffee queue.
Orders move automatically from NEW → BREWING → DONE at scheduled intervals.

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PostgreSQL Database

• Ensure your PostgreSQL database is running and reachable before starting the application.
• Before running the application:

1. Create the PostgreSQL database:

CREATE DATABASE coffeequeue;

2. Execute the SQL script createSchema.sql (found in the root folder of this project) to create the required tables and schema.

Build and Run

1. Build the application

Open a terminal in the project directory and run:

mvn clean install

This will compile the code and create the executable JAR file in the target/ directory.

2. Run the application with default settings

java -jar ./target/coffeequeue-0.0.1-SNAPSHOT.jar

By default, the application will use the settings in application.properties.

3. Customize database connection and server port

You can override the database connection details and application port using command-line arguments:

java -jar ./target/coffeequeue-0.0.1-SNAPSHOT.jar \
  --spring.datasource.url=jdbc:postgresql://<db-host>:<db-port>/coffeequeue \
  --server.port=<app-port> \
  --spring.datasource.username=<username> \
  --spring.datasource.password=<password>

Example:

java -jar ./target/coffeequeue-0.0.1-SNAPSHOT.jar \
  --spring.datasource.url=jdbc:postgresql://localhost:5432/coffeequeue \
  --server.port=8080 \
  --spring.datasource.username=postgres \
  --spring.datasource.password=postgres

Kubernetes (Helm)

The Kubernetes manifests are packaged as a Helm chart in charts/coffeequeue.

Install the chart:

helm install coffeequeue ./charts/coffeequeue

Package the chart:

helm package ./charts/coffeequeue

Defaults use a Postgres init job. To disable it or enable the init container:

helm install coffeequeue ./charts/coffeequeue \
  --set postgres.initJob.enabled=false \
  --set postgres.initContainer.enabled=true

4. API Endpoints

The Coffee Queue application exposes the following REST endpoints:

Endpoint	Method	Description	Request Parameters	Example Request	Example Response
/health	GET	Checks if the application is running	None	GET /health	"OK"
/order	POST	Creates a new coffee order for a customer	name – customer’s name (String)	POST /order?name=MickyMouse	json { "id": 1, "customerName": "MickyMouse", "status": "NEW", "createdAt": "2025-10-29T10:00:00", "updatedAt": "2025-10-29T10:00:00" }
/status	GET	Retrieves all orders for a specific customer	name – customer’s name (String)	GET /status?name=MickyMouse	json [ { "id": 1, "customerName": "MickyMouse", "status": "NEW", "createdAt": "2025-10-29T10:00:00", "updatedAt": "2025-10-29T10:00:00" } ]
/numberOfCoffees	GET	Returns a count of orders by status (NEW, BREWING, DONE)	None	GET /numberOfCoffees	json { "NEW": 2, "BREWING": 1, "DONE": 5 }

5. Notes

Order Processing: Orders will automatically transition from NEW → BREWING → DONE at scheduled intervals:

NEW → BREWING and BREWING → DONE every 1–3 seconds

Timestamps: createdAt is when the order was created; updatedAt is updated each time the status changes. Example Flow:

# Create a new order for MickyMouse
POST /order?name=MickyMouse

# Check MickyMouse's orders
GET /status?name=MickyMouse

# See total orders by status
GET /numberOfCoffees

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