In today’s software development environment, Spring Boot has established itself as an essential framework for building Java-based applications. This course aims to help you understand the basics of backend development using Spring Boot, and also to learn in detail about the concepts of CI/CD (Continuous Integration/Continuous Delivery).
1. What is Spring Boot?
Spring Boot is a tool that helps in easily developing Spring applications based on the Spring Framework. Its main purpose is to minimize configuration and support the rapid creation of applications that can run in production environments.
1.1. Features of Spring Boot
- Autoconfiguration: Spring Boot automatically configures the settings required by the application, reducing the need for developers to manually write configuration files.
- Standalone Applications: Spring Boot offers an embedded server, allowing it to be deployed as a standalone application without a WAR file or separate server configuration.
- Starter Dependencies: It provides starter dependencies that pre-configure the dependencies of required libraries for various functionalities.
- Production-ready Features: It includes various features such as metrics, health checks, and monitoring to enhance security in production environments.
2. Setting Up the Spring Boot Environment
To use Spring Boot, you must first set up your development environment. You need to install Java JDK, an IDE (e.g., IntelliJ IDEA or Eclipse), and Maven or Gradle.
2.1. Creating a Gradle or Maven Project
You can easily create a Spring Boot project using the Spring Initializr website (https://start.spring.io) or through your IDE. After creating a basic project, you can add dependencies according to the required functionalities.
2.2. Key Dependencies
The key dependencies to introduce for backend development include the following:
- Spring Web: A module for building RESTful APIs.
- Spring Data JPA: An ORM (Object-Relational Mapping) library for interacting with databases.
- Spring Security: Manages authentication and authorization.
- Spring Boot DevTools: Supports hot swapping (Modify and Reload) during development to speed up the development process.
3. Building a REST API with Spring Boot
Let’s understand the process of building a simple REST API using Spring Boot.
3.1. Creating an Entity Class
package com.example.demo.model;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
@Entity
public class User {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String name;
private String email;
// getters and setters
}
3.2. Creating a Repository Interface
package com.example.demo.repository;
import com.example.demo.model.User;
import org.springframework.data.jpa.repository.JpaRepository;
public interface UserRepository extends JpaRepository<User, Long> {
}
3.3. Creating a Service Class
package com.example.demo.service;
import com.example.demo.model.User;
import com.example.demo.repository.UserRepository;
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<User> getAllUsers() {
return userRepository.findAll();
}
public User saveUser(User user) {
return userRepository.save(user);
}
}
3.4. Creating a Controller Class
package com.example.demo.controller;
import com.example.demo.model.User;
import com.example.demo.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import java.util.List;
@RestController
@RequestMapping("/api/users")
public class UserController {
@Autowired
private UserService userService;
@GetMapping
public List<User> getAllUsers() {
return userService.getAllUsers();
}
@PostMapping
public User createUser(@RequestBody User user) {
return userService.saveUser(user);
}
}
4. What is CI/CD?
CI/CD stands for Continuous Integration and Continuous Delivery/Deployment, which refers to a series of automated processes in software development. This approach automatically tests and deploys the application whenever a developer changes the code, making it a methodology that enhances efficiency and reduces errors.
4.1. Continuous Integration (CI)
Continuous Integration is a method where developers regularly (usually multiple times a day) integrate their code into a central repository. This practice allows for early detection of code changes, ensures that builds and tests are performed automatically, and improves quality. Key elements of CI include:
- Version Control System: Using version control tools like Git or SVN to manage the history of code changes.
- Automated Builds: Using CI tools such as Jenkins or CircleCI to automate the build process whenever code changes occur.
- Automated Testing: Automated execution of unit tests, integration tests, etc., to verify the functioning of components.
4.2. Continuous Delivery/CD
Continuous Delivery is a process of automatically deploying new updates to the production environment. Applications that have been integrated through CI and have successfully passed testing are automatically deployed to the actual environment. CD is divided into two approaches:
- Continuous Delivery: All changes are kept in a deployable state, but actual deployment is performed manually.
- Continuous Deployment: All changes are automatically deployed to production, and deployment occurs automatically after passing tests.
5. CI/CD Tools
There are various CI/CD tools available. They can be chosen based on their different features and characteristics.
5.1. Jenkins
Jenkins is one of the most popular open-source CI/CD tools, providing infinite scalability through a variety of plugins. It supports pipeline DSL, allowing you to visually build CI/CD pipelines.
5.2. GitLab CI/CD
GitLab is a code repository platform with powerful CI/CD features built-in. With GitLab CI/CD, testing and deployment can occur instantly when code is pushed.
5.3. CircleCI
CircleCI is a cloud-based CI/CD tool that offers fast speed and easy setup. It allows for the easy configuration of complex pipelines using YAML files.
6. Integrating Spring Boot with CI/CD
Integrating Spring Boot applications into a CI/CD pipeline is very important. It typically includes the following steps:
- Connecting to a Code Repository: Connecting to platforms like GitHub or GitLab to detect code changes in real-time.
- Building and Testing: Building the code and performing automated tests to ensure code quality.
- Deployment: Deploying tested and verified code to the production environment.
7. Conclusion
The combination of backend development using Spring Boot and CI/CD plays a very important role in modern software development. It enables rapid development, high quality, and continuous deployment, significantly enhancing team productivity. Through this course, you will gain a basic understanding of Spring Boot and CI/CD and will be able to apply it to real projects.