Hello! In this course, we will learn how to develop a backend using Spring Boot. In particular, we will explain in detail how to implement login and logout functions and user registration using Spring Security. This course is structured for beginners to intermediate developers, and code and explanations will be provided to make it easy to follow.

1. Understanding Spring Boot and Spring Security

Spring Boot is an application framework based on the Spring framework that supports easy configuration and rapid deployment. It is particularly useful for building microservice architectures. Spring Security is a powerful security framework for handling secure and authenticated requests.

2. Setting Up the Development Environment

First, we need to set up the development environment. Below are the required tools.

• Java JDK 11 or higher
• IntelliJ IDEA or Spring Tool Suite (STS)
• Maven or Gradle
• PostgreSQL or MySQL database

2.1. Creating a Project

Use Spring Initializr to create a new Spring Boot project. Add the following dependencies:

• Spring Web
• Spring Security
• Spring Data JPA
• H2 Database (for development)

2.2. Setting Dependencies

pom.xml
<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-security</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
    <dependency>
        <groupId>com.h2database</groupId>
        <artifactId>h2</artifactId>
        <scope>runtime</scope>
    </dependency>
</dependencies>

3. Implementing User Registration Functionality

To implement user registration functionality, we first need to define the required classes.

3.1. Creating the User Entity

src/main/java/com/example/demo/model/User.java
package com.example.demo.model;

import javax.persistence.*;

@Entity
@Table(name = "users")
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @Column(nullable = false, unique = true)
    private String username;

    @Column(nullable = false)
    private String password;

    public User() {}

    // getters and setters
}

3.2. Creating the UserRepository Interface

src/main/java/com/example/demo/repository/UserRepository.java
package com.example.demo.repository;

import com.example.demo.model.User;
import org.springframework.data.jpa.repository.JpaRepository;
import java.util.Optional;

public interface UserRepository extends JpaRepository<User, Long> {
    Optional<User> findByUsername(String username);
}

3.3. Implementing the UserService Class

src/main/java/com/example/demo/service/UserService.java
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.security.crypto.bcrypt.BcryptPasswordEncoder;
import org.springframework.stereotype.Service;

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

    @Autowired
    private PasswordEncoder passwordEncoder;

    public void registerUser(User user) {
        user.setPassword(passwordEncoder.encode(user.getPassword()));
        userRepository.save(user);
    }
}

3.4. Implementing the Registration Controller

src/main/java/com/example/demo/controller/AuthController.java
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.*;

@RestController
@RequestMapping("/auth")
public class AuthController {
    @Autowired
    private UserService userService;

    @PostMapping("/register")
    public String register(@RequestBody User user) {
        userService.registerUser(user);
        return "Registration successful!";
    }
}

4. Configuring Spring Security

Using Spring Security, we will set up basic authentication and authorization.

4.1. Creating the SecurityConfig Class

src/main/java/com/example/demo/config/SecurityConfig.java
package com.example.demo.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
import org.springframework.security.crypto.bcrypt.BcryptPasswordEncoder;
import org.springframework.security.crypto.password.PasswordEncoder;

@Configuration
@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {
    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .authorizeRequests()
                .antMatchers("/auth/register").permitAll() // Registration
                .anyRequest().authenticated() // Authentication required for all other requests
                .and()
            .formLogin() // Use default login form
                .permitAll()
                .and()
            .logout()
                .permitAll();
    }

    @Bean
    public PasswordEncoder passwordEncoder() {
        return new BcryptPasswordEncoder();
    }
}

5. Handling Login and Logout

Spring Security supports login and logout handling by default. We can use the login information as follows.

5.1. Authentication on Login

When logging in, if the username and password entered by the user match, a session is created. To verify the user’s password from the user database, we can implement `UserDetailsService`. We will use `UserService` to obtain the data.

5.2. Invalidating Session on Logout

When a user logs out, Spring Security invalidates the session and redirects to the URL specified in `logoutSuccessUrl`.

6. Implementing the Service Layer and Business Logic

To implement user registration and login functionality, we structure the business logic in the service layer. In this process, we interact with the database using JPA.

6.1. Validation on User Registration

src/main/java/com/example/demo/service/UserService.java
public void registerUser(User user) {
    if (userRepository.findByUsername(user.getUsername()).isPresent()) {
        throw new RuntimeException("User already exists.");
    }
    user.setPassword(passwordEncoder.encode(user.getPassword()));
    userRepository.save(user);
}

7. Configuring the Database

Set up the application to connect to the H2 database or another relational database (MySQL, PostgreSQL, etc.).

7.1. Setting application.properties

src/main/resources/application.properties
spring.datasource.url=jdbc:h2:mem:testdb
spring.datasource.driver-class-name=org.h2.Driver
spring.datasource.username=sa
spring.datasource.password=
spring.h2.console.enabled=true
spring.jpa.hibernate.ddl-auto=update

8. Testing and Validation

Complete the tutorial to verify that all functionalities work correctly. Use Postman or other API testing tools to test API calls.

8.1. API Test Scenarios

1. POST /auth/register: User registration
2. POST /login: User login (after registration)
3. GET /protected-endpoint: Accessible only to authenticated users

9. Conclusion and Deployment

Once all features have been tested and no modifications are needed, you will be ready to deploy the application. At this stage, you can deploy the application to cloud services such as AWS, Heroku, etc.

10. FAQ

10.1. What is the difference between Spring Boot and Spring Security?

Spring Boot is a framework used for rapidly prototyping and deploying applications, whereas Spring Security is a framework for managing the security of applications.

10.2. How do you handle duplicate usernames during registration?

The registration service checks for existing usernames, and an exception is thrown if the username already exists.

10.3. What is the recommended way to deploy a Spring Boot application to the cloud?

Spring Boot applications can be easily deployed using platforms like AWS Elastic Beanstalk, Heroku, and Google Cloud Platform.

11. Conclusion

I hope this course has enhanced your understanding of backend development based on Spring Boot. You learned how to build secure applications using Spring Security and maximize performance as well. Furthermore, please consider the deployment methods in actual operational environments.

If you found this article helpful, please check out other courses as well. Thank you!

Hello! In this lecture, we will learn how to develop a basic backend application using Spring Boot. In particular, we will delve into implementing login and logout functionalities, user registration functionality using Spring Security, and enhancing the user experience through view controllers.

1. Introduction to Spring Boot and Security

Spring Boot is an application development tool based on the Spring Framework, designed to help you build applications quickly without complex configurations. Spring Security is a powerful tool for managing the security of applications and makes it easy to handle authentication and authorization.

1.1. Requirements

• JDK 8 or higher
• IDE (IntelliJ IDEA, Eclipse, etc.)
• Maven or Gradle

1.2. Project Setup

To create a Spring Boot project, use Spring Initializr. Please add the following dependencies:

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
            <scope>runtime</scope>
        </dependency>
    

2. Implementing User Registration Functionality

To register a user, follow these steps:

2.1. Creating an Entity

Create a User entity to hold user information.

    @Entity
    public class User {
        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        private Long id;

        private String username;
        private String password;
        private String email;

        // Getters and Setters
    }
    

2.2. Creating a Repository Interface

Create a UserRepository to interact with the database using JPA.

    public interface UserRepository extends JpaRepository<User, Long> {
        Optional<User> findByUsername(String username);
    }
    

2.3. Writing a Service Class

Create a UserService class to handle registration logic.

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

        public User registerNewUser(User user) {
            // Additional business logic (e.g., password encryption)
            return userRepository.save(user);
        }
    }
    

2.4. Creating a Controller

Create a UserController that provides a REST API for user registration.

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

        @PostMapping("/register")
        public ResponseEntity<User> registerUser(@RequestBody User user) {
            User newUser = userService.registerNewUser(user);
            return ResponseEntity.ok(newUser);
        }
    }
    

2.5. Password Encryption

We will use bcrypt hash function to securely store passwords. The password will be encrypted in UserService.

    @Autowired
    private PasswordEncoder passwordEncoder;

    public User registerNewUser(User user) {
        user.setPassword(passwordEncoder.encode(user.getPassword()));
        return userRepository.save(user);
    }
    

3. Implementing Login and Logout Functionality

Now that user registration is complete, we will implement the login and logout functionalities.

3.1. Spring Security Configuration

Set up Spring Security to implement basic user authentication. Write the SecurityConfig class.

    @Configuration
    @EnableWebSecurity
    public class SecurityConfig extends WebSecurityConfigurerAdapter {
        @Autowired
        private UserDetailsService userDetailsService;

        @Override
        protected void configure(AuthenticationManagerBuilder auth) throws Exception {
            auth.userDetailsService(userDetailsService).passwordEncoder(passwordEncoder());
        }

        @Override
        protected void configure(HttpSecurity http) throws Exception {
            http.csrf().disable()
                .authorizeRequests()
                .antMatchers("/api/users/register").permitAll()
                .anyRequest().authenticated()
                .and()
                .formLogin()
                .loginPage("/login")
                .permitAll()
                .and()
                .logout()
                .permitAll();
        }

        @Bean
        public PasswordEncoder passwordEncoder() {
            return new BCryptPasswordEncoder();
        }
    }
    

3.2. Creating Login Page and Logout Functionality

Create a login page and implement logout functionality. The login page is written in HTML.

    <form action="/login" method="post">
        <label>Username:</label>
        <input type="text" name="username" required>
        <label>Password:</label>
        <input type="password" name="password" required>
        <button type="submit">Login</button>
    </form>
    

4. Implementing View Controller

Finally, we will create a view controller to add functionality for displaying data to the user.

4.1. Creating a Controller

Create a controller that returns HTML pages using Spring MVC’s view controllers.

    @Controller
    public class ViewController {
        @GetMapping("/register")
        public String registerForm(Model model) {
            model.addAttribute("user", new User());
            return "register";
        }

        @GetMapping("/login")
        public String loginForm() {
            return "login";
        }
    }
    

4.2. Using Thymeleaf Templates

Use Thymeleaf to render HTML in the view layer. Add a register.html file to the resources/templates folder.

    <html xmlns:th="http://www.w3.org/1999/xhtml">
    <body>
        <form action="@{/api/users/register}" th:object="${user}" method="post">
            <label>Username:</label>
            <input type="text" th:field="*{username}" required>
            <label>Password:</label>
            <input type="password" th:field="*{password}" required>
            <button type="submit">Register</button>
        </form>
    </body>
    

5. Conclusion

You have now learned how to build a simple backend application with user registration, login, and logout functionality using Spring Boot. This serves as a foundation for developing more complex applications using Spring Boot. Next steps may include database integration, API documentation, and frontend integration. If you have any questions or need further assistance, please leave a comment!

Hello! In this blog post, we will learn how to develop a backend application using Spring Boot, implement login and logout functionalities with Spring Security, and add a user registration feature. We will also cover how to create repositories for interacting with the database. This course is suitable for everyone from beginners to intermediate learners.

1. What is Spring Boot?

Spring Boot is a framework that helps develop applications quickly based on the Spring Framework. By using Spring Boot, we can minimize complex configurations and swiftly create microservices or standalone applications. The main features of Spring Boot are:

• Auto Configuration: Easily configure without complex XML settings through code and annotations.
• Starters: Use starters that bundle the necessary dependencies for easy dependency management.
• Ease of Deployment: Easily deployable as a standalone executable JAR file.

2. Setting Up the Project

You can quickly create a Spring Boot project using Spring Initializr. Select the necessary dependencies, create a Maven project, and import it into your IDE. Below is a list of essential dependencies:

• Spring Web
• Spring Security
• Spring Data JPA
• H2 Database

2.1 Creating the Project with IntelliJ

Let’s look at how to create a project using IntelliJ. First, open IntelliJ and follow these steps:

1. Select File > New > Project
2. Select Spring Initializr and click ‘Next’
3. Enter Group, Artifact, Name, and click ‘Next’
4. Select necessary dependencies and click ‘Finish’

3. Configuring Spring Security

Spring Security is a powerful framework that is used to add security features to Spring applications. It supports easy implementation of authentication and authorization functionalities. Here, we will implement basic login/logout features.

3.1 Adding Spring Security Dependency

Although this dependency is already included in the dependencies selected from Spring Initializr, you can additionally add the Spring Security dependency in the pom.xml file if needed:

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-security</artifactId>
</dependency>

3.2 Creating the SecurityConfig Class

To configure Spring Security, we create the `SecurityConfig` class. This class configures the security filter chain for Spring Security:

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;

@Configuration
@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {
    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .authorizeRequests()
                .antMatchers("/login", "/register").permitAll() // Allow access to login and registration pages
                .anyRequest().authenticated() // All other requests require authentication
            .and()
            .formLogin()
                .loginPage("/login") // Set login page
                .permitAll() // Allow all users to access
            .and()
            .logout()
                .permitAll(); // Allow logout functionality
    }
}

4. Implementing User Registration

To implement the registration feature, we will create a User entity and UserRepository. Then we will create a service that saves user information to the database.

4.1 Creating the User Entity

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 username;
    private String password;
    
    // getters and setters
}

4.2 Creating the UserRepository Interface

import org.springframework.data.jpa.repository.JpaRepository;
import java.util.Optional;

public interface UserRepository extends JpaRepository<User, Long> {
    Optional<User> findByUsername(String username);
}

4.3 Implementing the Registration Service

We will create a UserService class to handle user information for registration:

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
import org.springframework.stereotype.Service;

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

    private BCryptPasswordEncoder passwordEncoder = new BCryptPasswordEncoder();

    public void registerUser(User user) {
        String encodedPassword = passwordEncoder.encode(user.getPassword());
        user.setPassword(encodedPassword); // Encrypt password
        userRepository.save(user); // Save user information
    }
}

4.4 Implementing the Registration Controller

We will create a controller to handle registration requests:

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.ModelAttribute;

@Controller
public class UserController {
    @Autowired
    private UserService userService;

    @GetMapping("/register")
    public String showRegistrationForm(Model model) {
        model.addAttribute("user", new User());
        return "register"; // Redirect to registration page
    }

    @PostMapping("/register")
    public String registerUser(@ModelAttribute User user) {
        userService.registerUser(user); // Process user registration
        return "redirect:/login"; // Redirect to login page
    }
}

5. Implementing View Templates

In Spring Boot, we mainly use Thymeleaf to create HTML templates. Let’s create view templates for the login and registration pages.

5.1 Login Page

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
    <title>Login Page</title>
</head>
<body>
    <h1>Login</h1>
    <form th:action="@{/login}" method="post">
        <div>
            <label>Username:</label>
            <input type="text" name="username" required />
        </div>
        <div>
            <label>Password:</label>
            <input type="password" name="password" required />
        </div>
        <button type="submit">Login</button>
    </form>
    <a th:href="@{/register}">Go to registration</a>
</body>
</html>

5.2 Registration Page

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
    <title>Registration Page</title>
</head>
<body>
    <h1>Register</h1>
    <form th:action="@{/register}" method="post">
        <div>
            <label>Username:</label>
            <input type="text" name="username" required />
        </div>
        <div>
            <label>Password:</label>
            <input type="password" name="password" required />
        </div>
        <button type="submit">Register</button>
    </form>
    <a th:href="@{/login}">Go to login</a>
</body>
</html>

6. Conclusion

In this post, we learned how to develop a backend application using Spring Boot and how to implement login and registration features through Spring Security. We gained an understanding of the basic usage of Spring Boot and its security features through a simple example. I hope this practical exercise leads to effective learning.

As you proceed with future projects, try implementing more complex features and learning advanced technologies. I wish you to become a developer who continuously learns and grows. Thank you!

In this course, we will learn how to develop backend applications using Spring Boot. Specifically, we will implement login/logout functionality and a registration system utilizing Spring Security, as well as cover the necessary content for creating views. Through this course, you will gain an understanding of the basic structure of web applications and their security aspects.

1. Introduction to Spring Boot

Spring Boot is a Java-based framework that provides tools for developing Spring applications quickly and simply. It simplifies the complex configurations often encountered in traditional Spring development, allowing developers to focus on business logic.

1.1 Advantages of Spring Boot

• Auto-configuration: Spring Boot automatically configures the necessary settings when running the application.
• Standalone: Spring Boot applications can run independently, including an embedded Tomcat server.
• Convenient dependency management: Library dependencies can be easily managed via Maven or Gradle.

2. Setting Up Security with Spring Security

Spring Security provides robust authentication and authorization features for securing Spring-based applications. In this section, we will learn how to configure Spring Security and implement login and logout functionality.

2.1 Adding Dependencies

To use Spring Security, add the following dependencies to the build.gradle file:

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-security'
    implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
    implementation 'org.springframework.boot:spring-boot-starter-web'
    runtimeOnly 'com.h2database:h2'
}

2.2 Creating the Spring Security Configuration Class

We will create a SecurityConfig class for Spring Security configuration. The code below includes basic login and logout settings:

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
import org.springframework.security.crypto.password.PasswordEncoder;

@Configuration
@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(AuthenticationManagerBuilder auth) throws Exception {
        auth.inMemoryAuthentication()
            .withUser("user").password(passwordEncoder().encode("password")).roles("USER")
            .and()
            .withUser("admin").password(passwordEncoder().encode("admin")).roles("ADMIN");
    }

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .authorizeRequests()
                .antMatchers("/", "/register").permitAll()
                .anyRequest().authenticated()
                .and()
            .formLogin()
                .loginPage("/login")
                .permitAll()
                .and()
            .logout()
                .permitAll();
    }

    @Bean
    public PasswordEncoder passwordEncoder() {
        return new BCryptPasswordEncoder();
    }
}

3. Implementing Registration Functionality

To implement the registration functionality, we will create an entity to store user information and a repository for database integration. After that, we will create a controller to handle the registration process.

3.1 Creating the User Entity

We will write a User class to store user information:

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 username;
    private String password;
    private String email;

    // getters and setters
}

3.2 Creating the UserRepository

We will create a repository to manage User information using JPA:

import org.springframework.data.jpa.repository.JpaRepository;

public interface UserRepository extends JpaRepository {
    User findByUsername(String username);
}

3.3 Creating Registration Form and Controller

We will create an HTML form for registration and a controller to handle it. We will create a RegisterController to process registration requests:

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
@RequestMapping("/register")
public class RegisterController {

    @Autowired
    private UserRepository userRepository;

    @GetMapping
    public String showRegisterForm(Model model) {
        model.addAttribute("user", new User());
        return "register";
    }

    @PostMapping
    public String registerUser(User user) {
        user.setPassword(new BCryptPasswordEncoder().encode(user.getPassword()));
        userRepository.save(user);
        return "redirect:/login";
    }
}

3.4 Creating Registration HTML Form

We will create a form for registration:

    


    
Registration
    

        Username:
        
        

        Password:
        
        

        Email:
        
        

        Register
    

4. Implementing Login/Logout Functionality

We will implement the login and logout functionality to allow users to securely access the system.

4.1 Creating Login HTML Form

We will create the login form:

    


    
Login
    

        Username:
        
        

        Password:
        
        

        Login
    

4.2 Handling Logout

The logout functionality is provided by Spring Security by default, specifying a logout URL through which logout is processed. It uses the default /logout path.

5. Creating Views

Now that we have implemented the registration and login functionality, we will create the views that will be displayed to the users. When using Spring Boot, we mainly use a template engine called Thymeleaf.

5.1 Setting Up Thymeleaf

To use Thymeleaf, add the following dependency to the build.gradle file:

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-thymeleaf'
}

5.2 Creating a Basic Home Page

We will create a controller and view to display the home page. Below is the HTML code representing the home page:

    


    
Home Page
    

        Hello, User!
        Logout
    
    

        Login
        

        Register
    

6. Conclusion

In this way, we have built a web application with simple registration and login/logout functionality using Spring Boot. Through this project, you will understand the basic usage of Spring Boot and implementing security features using Spring Security.

6.1 Next Steps

You can now consider adding more complex features or developing a RESTful API to communicate with the frontend. It is also good to think about integration with mobile applications or other clients. If necessary, integrating external authentication services like OAuth2 is also a good direction.

6.2 Additional Resources

If you want more information, please refer to the official Spring Boot documentation and Spring Security documentation:

• Spring Boot Project
• Spring Security Project