Spring-LearningByDoing-EazySchool

This repository is my Spring Boot learning journal in code. It's a single, evolving project based on the EazySchool web application, where I've applied every concept I've learned, from core principles to advanced features. This is a practical, 'learn by doing' approach to mastering the Spring Framework.

📚 Topics & Concepts Covered

This project is a comprehensive application that covers the following major areas of the Spring Framework:

1. Spring Core

• Inversion of Control (IoC) & Dependency Injection (DI)
• Spring Context & Beans (@Bean, @Component, Stereotype Annotations)
• Bean Lifecycle (@PostConstruct, @PreDestroy) & Scopes (Singleton, Prototype)
• Autowiring (Field, Setter, Constructor) & Circular Dependencies
• Configuration (XML & Annotation-based)

2. Aspect-Oriented Programming (AOP)

• Understanding AOP Jargons (Aspect, JoinPoint, Advice)
• Types of Advices: @Around, @Before, @AfterThrowing, @AfterReturning
• Implementing AOP for logging and performance monitoring.

3. Spring MVC & Web Applications

• Introduction to Spring Boot & its features (Auto-configuration, DevTools)
• Building Web Apps with @Controller
• Dynamic content with Thymeleaf (Templates, Layouts)
• Handling requests with @RequestParam and @PathVariable
• Java Bean Validations (@Valid) and Custom Validations
• Global Exception Handling with @ControllerAdvice and @ExceptionHandler
• Web Scopes (@RequestScope, @SessionScope)

4. Spring Security

• Authentication vs. Authorization
• In-Memory & JDBC-based Authentication
• Custom Login/Logout functionality
• Securing web pages and endpoints (permitAll, denyAll)
• CSRF Protection & implementation
• Password Hashing with BCryptPasswordEncoder
• Thymeleaf-Security integration for dynamic UI.

5. Database & Spring Data

• Spring JDBC: JdbcTemplate (Insert, Update, Select)
• Databases: H2 (In-memory) & MySQL
• Spring Data JPA: JpaRepository, CrudRepository
• ORM Concepts (Fetch Types, Cascade Types)
• Entity Relationships: @OneToOne, @OneToMany, @ManyToMany
• JPA Auditing (@CreatedBy, @LastModifiedDate)
• Advanced Queries: Static/Dynamic Sorting, Pagination, Custom Queries (@Query, @NamedQuery)

6. RESTful Services

• Building REST APIs with @RestController
• @RequestBody, @ResponseBody, ResponseEntity
• Handling CORS (@CrossOrigin)
• Consuming REST services using RestTemplate, WebClient, and OpenFeign
• Spring Data REST & HAL Explorer

7. Spring Boot Features

• Logging (Logback configurations)
• Externalized Properties (@Value, @ConfigurationProperties)
• Profiles (application-dev.properties, application-prod.properties)
• Spring Boot Actuator (Health, Metrics, Info)
• Spring Boot Admin (Monitoring UI)

---

🛠️ Prerequisites

• JDK 11 or higher
• Apache Maven
• An IDE (like IntelliJ IDEA or Eclipse)
• A MySQL database server

---

🚀 How to Run This Project

This project requires manual configuration for the database to run.

1. Clone the repository:

   git clone [https://github.com/YOUR_USERNAME/Spring-LearningByDoing-EazySchool.git](https://github.com/YOUR_USERNAME/Spring-LearningByDoing-EazySchool.git)
   cd Spring-LearningByDoing-EazySchool

2. Database Configuration: This project is configured to use MySQL for its production profile. You must create a MySQL database and update the database credentials.

   • Open src/main/resources/application-prod.properties.
   • Update the following properties with your own MySQL server details:

   spring.datasource.url=jdbc:mysql://localhost:3306/your_db_name
   spring.datasource.username=your_username
   spring.datasource.password=your_password

3. Activate the Profile: By default, the application might use the in-memory H2 database (dev profile). To run it with your MySQL database, you need to activate the prod profile.

   • Open src/main/resources/application.properties.
   • Set the active profile to prod:

   spring.profiles.active=prod

4. Run the application: You can run the application using your IDE's "Run" command on the main EazySchoolApplication class or via the Maven command line:

   mvn spring-boot:run

5. Access the application: Open your browser and navigate to http://localhost:8080.

---

💡 Project Notes

• AWS Deployment: The original learning path included modules on deploying to AWS Elastic Beanstalk. However, I did not complete this final deployment step as it required a credit card to create an AWS account. The project is fully built and functional for local or other deployment methods.
• H2 Console: If you run with the dev profile, you can access the H2 in-memory database console at http://localhost:8080/h2-console.