DrewErskine / Blog

Blog Application Setup Guide

1. Project Scaffolding

• Spring Initializr - Spring Initializr
  • Gradle - Groovy: Package name = peep.pea.blog
  • Java: Version 21, Packaging = jar
  • Spring Boot: Version 3.3.0

2. Dependencies for Spring Initializr

Ensure to include the following dependencies when setting up your project via Spring Initializr:

• Spring Web: For building web applications.
• Spring Data JPA: For database integration using Java Persistence API.
• Spring Security: For authentication and authorization.
• PostgreSQL Driver: To connect to PostgreSQL database.
• H2 Database: For in-memory database during development and testing.
• Lombok: To reduce boilerplate code like getters, setters.

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3. Domain Model

• Entities: Define Java classes that map to database tables. Typical entities include Post, Comment, and User.
• Repositories: Utilize Spring Data JPA to automatically implement interfaces for database interactions.

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4. Business Logic

• Services: Encapsulate business logic related to posts and comments within service classes. These handle transactions and ensure adherence to business rules.
• DTOs: Define Data Transfer Objects to safely transfer data between the API layer and the client, safeguarding sensitive information.

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5. API Layer

• REST Controllers: Manage HTTP requests and responses, interfacing with service classes to process business logic.
• Exception Handling: Employ @ControllerAdvice to globally manage exceptions and provide cleaner error responses.

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6. Security Configuration

• JWT for Authentication: Configure Spring Security to utilize JSON Web Tokens (JWTs) for stateless authentication.
• Authorization: Implement role-based access control to manage user access to resources based on their roles.

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About Database Usage

• JPA (Java Persistence API): Manages data interaction between Java objects and relational databases, with Spring Data JPA providing an abstraction layer that simplifies data manipulation.
• JDBC (Java Database Connectivity): The underlying technology for database interactions, managed by JPA implementations like Hibernate.
• H2 Database: Used for testing purposes due to its in-memory capabilities.
• PostgreSQL Driver: Connects your application to the PostgreSQL database.
• Lombok: Simplifies Java code by automatically generating getters, setters, and other common code.

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peep.pea.blog.user

Overview

The user package in the application manages user information, including registration, profile updates, and authentication.

Components

• User.java: Represents the user entity with fields such as:

  1. username
  2. password
  3. email
  4. role
  5. last online timestamp
  6. profile picture URL This record supports the straightforward transfer of data within the application.

• UserController.java: The UserController handles CRUD operations on users. It includes methods for:

  1. Retrieving a single user by ID.
  2. Creating a new user.
  3. Listing all users with pagination. The controller uses Pageable and UriComponentsBuilder, which are best practices for RESTful APIs.

• UserService.java: The UserService manages the business logic associated with user operations. It provides methods to:

  1. Create a user.
  2. Retrieve a user by ID.
  3. Update user details.
  4. Delete a user.
  5. Fetch all users with pagination. This service ensures that operations like updating user details respect the immutability of the user record by creating a new record.

• UserRepository.java: Extends both CrudRepository and PagingAndSortingRepository, providing comprehensive CRUD operations and pagination capabilities. It includes methods to:

  1. Find users by ID and username.
  2. Save and delete users.
  3. Check for the existence of a username. This repository is integral to the data handling layer, directly interacting with the database.