Product Pagination and Sorting Application

This is a Spring Boot application that provides a REST API for managing products with pagination and sorting capabilities. The application uses a PostgreSQL database, which is configured and run using Docker Compose.

Prerequisites

To run this application, ensure you have the following installed:

• Docker: Required to run the PostgreSQL database.
  • Windows: Install Docker Desktop.
  • macOS: Install Docker Desktop.
  • Linux (e.g., Ubuntu): Install Docker and Docker Compose.
• Java 17 or later: Required to run the Spring Boot application.
• Maven: The project uses Maven for building and running. The Maven Wrapper (./mvnw) is included, so you don't need to install Maven separately.
• Git (optional): To clone the repository.

Project Setup

1. Clone the Repository:

   git clone https://github.com/stuart7j/pagination-sorting.git
   cd pagination-sorting

2. Verify Docker Installation: Ensure Docker and Docker Compose are installed and running:

   docker --version
   docker-compose --version

   For Docker Desktop on Windows or macOS, confirm the application is running.

Running the Application

Step 1: Start the PostgreSQL Database

The application uses a PostgreSQL database, configured in the docker-compose.yaml file.

1. Run Docker Compose: From the project root (where docker-compose.yaml is located), start the PostgreSQL container in detached mode:

   docker-compose up -d

2. Verify the Container is Running: Check that the pg_products container is up:

   docker ps

   You should see a container named pg_products with the postgres:15 image, listening on port 5432.

3. Database Configuration: The PostgreSQL database is configured with:

   • Database Name: productsdb
   • User: postgres
   • Password: postgres
   • Port: 5432 (mapped to localhost:5432)

   The application is preconfigured to connect to this database. No additional setup is needed unless you modify the application.properties or application.yml file.

Step 2: Build and Run the Spring Boot Application

The project includes a Maven Wrapper (./mvnw), so you don't need to install Maven.

1. Run the Application: From the project root, execute:

   ./mvnw spring-boot:run

   This command:

   • Downloads dependencies (if not already cached).
   • Compiles the code.
   • Starts the Spring Boot application.

2. Verify the Application is Running: Once started, the application is available at http://localhost:8059. Test the API using a tool like Postman or cURL:

   curl http://localhost:8059/api/products

   This returns a paginated list of products sorted by id in ascending order (default).

Step 3: Accessing the API

The application provides a REST API for managing products. Key endpoints include:

• GET /api/products: Retrieves a paginated and sorted list of products.

  • Query Parameters:

    • page (default: 0): Page number.
    • size (default: 10): Page size.
    • sort (default: id,asc): Sort criteria (format: property,direction, e.g., price,desc).
    • category (optional): Filter by category.
    • minPrice (optional): Filter by minimum price.
    • maxPrice (optional): Filter by maximum price.

  • Example:

    curl "http://localhost:8059/api/products?sort=price,desc&category=electronics"

Stopping the Application

1. Stop the Spring Boot Application: Press Ctrl+C in the terminal where ./mvnw spring-boot:run is running.

2. Stop the PostgreSQL Container: To stop and remove the Docker container:

   docker-compose down

   To also remove the database volume (deleting all data):

   docker-compose down -v

Troubleshooting

• PostgreSQL Container Not Starting:

  • Check if port 5432 is in use:

    netstat -an | grep 5432

    If another service is using port 5432, stop it or change the port mapping in docker-compose.yaml (e.g., 5433:5432).

  • Verify Docker is running: Ensure Docker Desktop (Windows/macOS) or the Docker daemon (Linux) is active.

• Application Fails to Connect to Database:

  • Confirm the PostgreSQL container is running:

    docker ps

  • Verify the database settings in application.properties or application.yml:

    spring.datasource.url=jdbc:postgresql://localhost:5432/productsdb
    spring.datasource.username=postgres
    spring.datasource.password=postgres

  • Check application logs for errors:

    tail -f target/spring-boot.log

• API Returns Errors:

  • For Invalid sort parameter errors, ensure the sort parameter is in the format property,direction (e.g., id,asc).
  • Test with Postman or cURL to verify query parameters.

• Maven Issues:

  • If ./mvnw spring-boot:run fails, confirm Java 17+ is installed:

    java --version

  • Clear the Maven cache and retry:

    ./mvnw clean

Project Structure

• src/main/java: Java source code, including ProductController and ProductService.
• src/main/resources/application.properties: Configuration for the database and Spring Boot.
• docker-compose.yaml: Defines the PostgreSQL service.
• pom.xml: Maven configuration with dependencies.

Notes

• PostgreSQL data is persisted in a Docker volume (pgdata). To reset the database, remove the volume with docker-compose down -v.
• The application runs on port 8059 by default. To change this, update server.port in application.properties.