Spring Boot Backend Development Course, Exploring Spring Boot Starter

Spring Boot is a framework that helps build Java-based web applications quickly and easily. In this course, we will cover the core concepts of Spring Boot and how to get started developing backend applications using Spring Boot starters.

1. What is Spring Boot?

Spring Boot is an extension of the Spring Framework, but it has a ‘convention over configuration’ structure, allowing complex Spring applications to be created easily with minimal configuration. With Spring Boot, anyone can start and deploy applications with ease.

1.1 Advantages of Spring Boot

  • Fast development cycles
  • Minimal configuration
  • Built-in web server support
  • Auto-configuration
  • Creating an environment that allows focus on business logic

2. What are Spring Boot Starters?

Spring Boot starters are a collection of various libraries that make it easy to create Spring Boot applications. Each starter comprehensively manages the various dependencies required for specific functionalities.

2.1 Types of Starters

  • spring-boot-starter-web: A starter for building web applications, which includes Spring MVC and Tomcat.
  • spring-boot-starter-data-jpa: Simplifies database access using JPA.
  • spring-boot-starter-security: A starter for security that supports authentication and authorization.
  • spring-boot-starter-test: A starter for testing, including testing libraries like JUnit and Mockito.
  • spring-boot-starter-actuator: Adds functionality to monitor the application’s status and metrics.

3. Using Spring Boot Starter

3.1 Adding Dependencies

To use Spring Boot starters, you first need to add dependencies using Maven or Gradle. For example, if you are using Maven, add the following dependency in your pom.xml file.



    org.springframework.boot
    spring-boot-starter-web

3.2 Creating a Simple Web Application

Now, let’s create a simple web application using Spring Boot starters. Below is an example of a basic REST controller.


import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class HelloController {

    @GetMapping("/hello")
    public String hello() {
        return "Hello, Spring Boot!";
    }
}

By sending a request to the /hello path using the code above, a simple REST API is created that returns the message “Hello, Spring Boot!”.

3.3 Running the Application

Once the application is set up, you can start the server by running the main application class. Calling the SpringApplication.run() method will run the embedded Tomcat server.


import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class Application {

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

4. Use Cases for Spring Boot Starters

We will cover various real-world use cases utilizing Spring Boot starters. In this process, we will explain how each starter is used and how actual business logic is structured.

4.1 Creating a CRUD Application

Let’s create a simple CRUD (Create, Read, Update, Delete) application using the Spring Boot Data JPA starter. You can set up a connection to the database and define entities to manage data.


// Entity definition
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Entity
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
    private String name;
    private String email;

    // getters and setters
}

4.2 Implementing the Service Layer

By implementing the service layer, we can process business logic and separate the controller from the database access layer.


import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class UserService {
    @Autowired
    private UserRepository userRepository;

    public List findAllUsers() {
        return userRepository.findAll();
    }

    public User saveUser(User user) {
        return userRepository.save(user);
    }

    // Other necessary methods
}

5. Conclusion and Next Steps

In this course, we explored the basic concepts of Spring Boot and Spring Boot starters, as well as how to create a simple web application. If you have learned how to use Spring Boot, it is now time to consider more complex business logic and deployment environments.

Additionally, Spring Boot allows you to extend functionality through various starters. Based on what you’ve learned in this course, we hope you will engage in a variety of projects.

Thank you!