URL Shortener Web Application

Create and manage short links for your website.

Features

• Show a table of short urls and actual urls mapping: http://localhost:8088/
• Generate a new short url from an url: http://localhost:8088/generate-link
• Revert and redirect to the actual url from a short url: http://localhost:8088/redirect
• Allow to custom short url's domain, for example: https://bit.ly, http://localhost:8088/settings

Project architecture

There are two separate apps client and server:

• The client is a ReactJS app. Built with create-react-app and using node-fetch to make REST requests to the server.
• The server is a Spring Boot app. Implementing Spring MVC, Spring REST, Spring Data JPA. Building with maven and testing with Spring Boot Test and JUnit.
• Database: PostgreSQL 13 via JDBC driver

Spring boot source code

For the spring boot source code, I did split the app into multiple packages and each of them handling different logic:

1. The com.urlshortener.app.config package contains Constants, LoadDatabase at the first server start up, and a WebConfig bean to allow CORS access via REST api.
2. The com.urlshortener.app.model package contains domain model entities and mapped with the PostgreSQL schema.
3. The com.urlshortener.app.repository package contains Spring Data JPA repositories.
4. The com.urlshortener.app.service package contains service classes to handle all business logic processing, for example: generate a short url from user input.
5. The com.urlshortener.app.web.rest package contains REST controller methods, exposing API endpoints.

Exception Handling

Exceptions are caught and thrown in the services during handling client requests. If there is any exception raised, it will be handled by a custom handler com.urlshortener.app.service.exception.RestResponseEntityExceptionHandler, which is essentially a using Spring's @ControllerAdvice annotation to return a BAD_REQUEST (200) code together with error message to the client.

Database schema

The database schema is located at src/main/resources/schema.sql. It will be run the first time when the server boots up, to create table schema for the app.

How to test

Run test:

./mvnw test

Please note that: there are only three test cases for LinkController to demonstrate how to write integration tests with spring boot.

How to run

The project is configured to build and deploy with docker and docker-compose. The project is built with single command and is a production ready deployment.

• Prerequisite: Install docker on your PC from https://docs.docker.com/get-docker/. Normally, that the only need to get docker ready (with Docker Desktop) from the above link. It will get docker engine and docker CLI installed and we are good to go.
• Unzip the project zip file url-shortener.zip and cd url-shortener
• Run ./deploy.sh script in the project root folder to get everything up and running.
• Wait for few seconds when deployment finished, access http://localhost:8088 to use the app.
• Done

What does the script do?

The deploy.sh basically does two important things:

1. Package the Spring Boot app with: ./mvnw clean package, and
2. Run docker compose up to build the client, server app, download postgres docker image, init the database, and start all servers.

Developer

Built from scratch by Yen Nguyen in May 2021