Master Core Spring Boot Concepts: Inversion of Control, Dependency Injection, and Your First Spring Boot Application

Ready to dive into Spring Boot? Learn the fundamental concepts of Spring Boot, including Inversion of Control (IoC), Dependency Injection, and building your first Spring Boot application. Whether you’re a beginner or an experienced developer looking to refresh your knowledge, this guide will help you get started with hands-on examples and practical advice. Watch the full session on our YouTube channel TechEazy Consulting and register for the full course at TechEazy Consulting

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Spring Boot is one of the most popular frameworks for building scalable and robust applications quickly. In this blog, we explore core Spring Boot concepts like Inversion of Control (IoC), Dependency Injection, and walk you through building your first Spring Boot application.

Key Topics Covered

1. Introduction to Spring Boot

Spring Boot simplifies Java development by providing a rich framework with features such as rapid development, microservices support, and transaction management. It makes Java development faster and more efficient, especially for microservices architectures used by companies like Netflix and many large financial institutions.

2. Inversion of Control (IoC)

Inversion of Control (IoC) is one of the most critical concepts in Spring Boot. Traditionally, the application code controls the flow of logic, but with IoC, the control is shifted to the framework, simplifying dependency management and cleanup.

Key Concept:

• IoC ensures that the framework controls object creation and lifecycle management, making your code cleaner and easier to maintain.

3. Dependency Injection (DI)

Dependency Injection (DI) is a design pattern that allows the Spring framework to inject dependencies into objects at runtime, rather than having objects create their dependencies manually.

Types of DI in Spring Boot:

• Constructor Injection

• Setter Injection

• Field Injection

These patterns simplify managing dependencies between classes, enabling better separation of concerns and more testable code.

Sample Code for Dependency Injection:

@Service
public class OrderService {

    private final OrderRepository orderRepository;

    @Autowired
    public OrderService(OrderRepository orderRepository) {
        this.orderRepository = orderRepository;
    }

    public List<Order> getAllOrders() {
        return orderRepository.findAll();
    }
}

4. Building Your First Spring Boot Application

Creating a Spring Boot project is easy, thanks to the Spring Initializer. Here’s how you can get started:

• Visit start.spring.io, select dependencies like Spring Web, and download your project.

• Use Maven or Gradle to manage dependencies, and set up your development environment.

Annotations used in Spring Boot:

• @SpringBootApplication: Combines @Configuration, @EnableAutoConfiguration, and @ComponentScan to simplify setup.

• @RestController: Used for creating RESTful web services.

• @Autowired: Used for dependency injection.

Sample Code to Get Started:

@SpringBootApplication
public class DemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }
}

With this setup, Spring Boot automatically configures your application, handles bean lifecycle management, and starts an embedded server.

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Next Steps

Learning Spring Boot core concepts is the first step toward becoming proficient in Java development. To explore these topics in more detail, including real-world use cases and hands-on projects, check out our video tutorial on our YouTube channel TechEazy Consulting.

For more hands-on learning and to master Spring Boot, register for our full course at TechEazy Consulting.