Spring vs Spring Boot

Spring and Spring Boot are popular frameworks in the Java ecosystem that simplify the development of enterprise and microservices-based applications. They provide powerful features to reduce boilerplate code and improve productivity while building robust systems.

• Enables development of scalable and production-ready applications
• Reduces complexity through simplified configuration and auto-setup
• Promotes modular design using reusable components

Spring
Spring is a comprehensive Java framework that provides support for building robust and scalable enterprise applications. It focuses on dependency injection, aspect-oriented programming, and modular architecture.

• Dependency Injection (DI): Simplifies object creation and management, promoting loose coupling.
• Modular Framework: Offers various modules like Spring MVC, Spring Security, Spring Data, allowing selective use.
• Flexible Configuration: Supports XML, annotations, and Java-based configuration for application setup.

Example: Spring application manually configured with beans and controllers:

@Configuration
@ComponentScan(basePackages = "com.example")
public class AppConfig {
    @Bean
    public UserService userService() {
        return new UserServiceImpl();
    }
}

@Controller
@RequestMapping("/users")
public class UserController {
    @Autowired
    private UserService userService;

    @GetMapping
    public String getUsers(Model model) {
        model.addAttribute("users", userService.getAllUsers());
        return "userList"; // JSP or HTML view
    }
}

// Main class deployed as WAR on external server like Tomcat
public class Main {
    public static void main(String[] args){

        // Deploy this app manually to an external server
    }
}