java-explore-with-me

Educational Project from Yandex Practicum Java Developer course.

Remarks on API

The API is divided into three logical parts:

public - available to any user without registration private - available only to registered and authorized users admin - available only to the admins of the service Note

The project doesn't handle any cross-cutting concerns like: user registration, authentication and authorization. It is assumed, that all requests come from a gateway service, which is responsible for registering, authorizing and authenticating a user as well as routing requests. Therefore the API is divided logically by endpoint names.

Tech Stack

• Java
• Spring Boot
• Lombok
• PostgreSQL
• Docker
• Hibernate
• Spring Data JPA

Architecture

The project consists of two modules (aka microservices):

• ewm-service
• stats-server

ewm service

Contains all the business logic necessary for the app functionality.

The service is split into logically divided packages:

• Categories
• Compilations
• Events
• Locations
• Requests
• UserManagement

Each package has its own functionality.

Categories

It has public and admin endpoints:

1. public provides functionality to:
   • get all categories by pages
   • get a category by its ID
2. admin provides functionality to:
   • create a new category
   • delete a category
   • update a category

Compilations

It has public and admin endpoints:

1. public provides functionality to:
   • get all compilations by filters:
     • pinned
     • from
     • size
   • get a compilation by its ID
2. admin provides functionality to:
   • create a compilation
   • delete a compilation
   • update a compilation

Events

It has public, private and admin endpoints:

1. public provides functionality to:
   • get events by location ID
   • get events by location coordinates
   • get all events
   • get event by id

Each request saves statistics to the statistics server. Requests that retrieve potentially large amount of data have filters:

• text that must be either in title or description of the event (optional)
• list of categories the event belongs to (optional)
• whether the event is paid or not (optional)
• start date of the event (optional)
• end date of the event (optional)
• only available for visiting (i.e. the event has not reached its participant limit) default value is false
• sort (optional):
  • event date
  • event views
• page start (default value 0)
• page size (default value 10)

2. admin provides functionality to:
   • search for events
   • update events (decline or accept the event)
3. private provides functionality to:
   • get all events added by current user
     • uses offset based paging
   • add event
   • get detailed info about an event added by current user by the event ID
   • update the event added by current user
   • get info about requests to participate in the event by other users
   • accept or decline participation requests by other users

Requests

It has only private part that provides functionality to:

• get all participation requests of a user by the user ID
• create a request to take part in an event
• cancel a request to take part n an event

UserManagement

It has only admin part that provides functionality to:

• get all users
  • uses offset-based paging
• create a user
• delete a user

stats server

1. Collects statistics about user interactions with public endpoints:
   • when user views a listing with events
   • when user views detailed information about an event
2. Provides endpoint to get statistics for a list of endpoints

Communication between services

Communication is performed via REST API by means of Spring's RestTemplate. That is the communication is synchronous.

API description

API of both services is described using OpenAPI.

stats server API:

https://github.com/Kir-Mi/java-explore-with-me/blob/main/ewm-stats-service-spec.json

ewm service API:

https://github.com/Kir-Mi/java-explore-with-me/blob/main/ewm-main-service-spec.json

First run:

mvn clean package

Then run:

docker-compose up -d

This command will create 4 docker containers:

1. stats-server
2. stats-db (postgres:14-alpine) running on port 5432, DB name: stats, user: postgres, password: postgres
3. ewm-service
4. ewm-db (postgres:14-alpine) running on port 5431, DB name: ewm, user: postgres, password: postgres

After successfully starting the project you can import Postman collections from folder /postman and run them one-by-one independently of each other.