SpringBootMastery_BanqueMisr

This project demonstrates the core concepts of Dependency Injection (DI) using plain Java, Spring Core, and Spring Boot.

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🔧 Project Structure & Tasks

1. DIY IoC/DI (Plain Java)

• Created Printer and UserService classes.
• Demonstrated constructor-based and setter-based injection.
• No Spring involved — just Java wiring.

2. Spring Core Introduction

• Added Spring Core dependency to a Maven project.
• Annotated components with @Component.
• Used AnnotationConfigApplicationContext to retrieve beans.

3. Spring Boot Setup

• Bootstrapped project using Spring Initializr.
• Created a simple REST controller (GreetingController) with a "Hello, Spring Boot!" endpoint.

4. Understanding @SpringBootApplication

• Demonstrated how to exclude DataSourceAutoConfiguration.
• Confirmed that no H2 DB starts when excluded.

5. Profiles & Configuration Binding

• Used application.properties and application-dev.yml.
• Bound configuration using @ConfigurationProperties("app").
• Exposed /title endpoint to return configured title.

6. Qualified Dependency Injection

• Created interface TimeService with two implementations:
  • SystemTimeService (marked @Primary)
  • MockTimeService (annotated with @Qualifier("mock"))
• Injected into a TimeController.

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🖼️ Screenshots & Notes

Check docs/annotations.md for:

• Sample output screenshots
• Console logs
• Controller outputs
• Configuration files

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📦 Tech Stack

• Java 17+
• Spring Core
• Spring Boot
• Maven