How to Build a Newsletter Website with Daily Email Updates (Step-by-Step)

A newsletter website allows users to subscribe and receive daily emails with useful content. In this tutorial, we will build a Spring Boot newsletter website that sends a random LeetCode question to users every day at 7:30 PM. 1. Project Setup Step 1: Create a Spring Boot Project Use Spring Initializr to create a Spring Boot project with the following dependencies: Spring Web (for REST API) Spring Boot Mail (for email service) Spring Data JPA (for database operations) Spring Scheduler (for scheduling jobs) H2 Database (or MySQL for persistence) Download the generated project and extract it. 2. Configure Dependencies Step 2: Add Dependencies in pom.xml org.springframework.boot spring-boot-starter-web org.springframework.boot spring-boot-starter-data-jpa org.springframework.boot spring-boot-starter-mail org.springframework.boot spring-boot-starter-thymeleaf org.springframework.boot spring-boot-starter 3. Configure Database and Email Step 3: Update application.properties # H2 Database Configuration (for development) spring.datasource.url=jdbc:h2:mem:testdb spring.datasource.driverClassName=org.h2.Driver spring.datasource.username=sa spring.datasource.password= spring.jpa.database-platform=org.hibernate.dialect.H2Dialect # Email Configuration spring.mail.host=smtp.gmail.com spring.mail.port=587 spring.mail.username=your-email@gmail.com spring.mail.password=your-email-password spring.mail.properties.mail.smtp.auth=true spring.mail.properties.mail.smtp.starttls.enable=true Note: Use environment variables or a secrets manager for email credentials in production. 4. Create Entity Model Step 4: Create User Entity @Entity public class User { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Long id; private String email; private boolean subscribed; // Constructors, Getters, and Setters } Step 5: Create Question Entity @Entity public class Question { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Long id; private String title; private String url; private String difficulty; } 5. Create Services Step 6: Implement Email Service @Service public class EmailService { @Autowired private JavaMailSender mailSender; public void sendEmail(String to, String subject, String text) { SimpleMailMessage message = new SimpleMailMessage(); message.setTo(to); message.setSubject(subject); message.setText(text); mailSender.send(message); } } Step 7: Implement Question Service @Service public class QuestionService { @Autowired private QuestionRepository questionRepository; public Question getRandomQuestion() { List questions = questionRepository.findAll(); return questions.isEmpty() ? null : questions.get(new Random().nextInt(questions.size())); } } 6. Implement Subscription System Step 8: Create User Repository @Repository public interface UserRepository extends JpaRepository { Optional findByEmail(String email); } Step 9: Create Subscription Controller @RestController @RequestMapping("/api/subscription") public class SubscriptionController { @Autowired private UserRepository userRepository; @PostMapping("/subscribe") public String subscribe(@RequestParam String email) { if (userRepository.findByEmail(email).isPresent()) { return "You are already subscribed!"; } userRepository.save(new User(email, true)); return "Subscription successful!"; } @PostMapping("/unsubscribe") public String unsubscribe(@RequestParam String email) { userRepository.findByEmail(email).ifPresent(user -> { user.setSubscribed(false); userRepository.save(user); }); return "Unsubscribed successfully!"; } } 7. Implement Email Scheduler Step 10: Schedule Daily Emails @Component public class EmailScheduler { @Autowired private QuestionService questionService; @Autowired private EmailService emailService; @Autowired private UserRepository userRepository; @Scheduled(cron = "0 30 19 * * ?") // Runs daily at 7:30 PM public void sendDailyQuestion() { Question question = questionService.getRandomQuestion(); if (question != null) { String subject = "Daily LeetCode Question - " + question.getDifficulty(); String body = "Today's question: " + question.getTitle() + "\n" + "Solve it here: " + question.getUrl(); List subscribers = userRepository.findAll();

Mar 25, 2025 - 15:54

A newsletter website allows users to subscribe and receive daily emails with useful content. In this tutorial, we will build a Spring Boot newsletter website that sends a random LeetCode question to users every day at 7:30 PM.

1. Project Setup

Step 1: Create a Spring Boot Project

Use Spring Initializr to create a Spring Boot project with the following dependencies:

Spring Web (for REST API)
Spring Boot Mail (for email service)
Spring Data JPA (for database operations)
Spring Scheduler (for scheduling jobs)
H2 Database (or MySQL for persistence)

Download the generated project and extract it.

2. Configure Dependencies

Step 2: Add Dependencies in `pom.xml`


    
        org.springframework.boot
        spring-boot-starter-web
    
    
        org.springframework.boot
        spring-boot-starter-data-jpa
    
    
        org.springframework.boot
        spring-boot-starter-mail
    
    
        org.springframework.boot
        spring-boot-starter-thymeleaf
    
    
        org.springframework.boot
        spring-boot-starter

3. Configure Database and Email

Step 3: Update `application.properties`

# H2 Database Configuration (for development)
spring.datasource.url=jdbc:h2:mem:testdb
spring.datasource.driverClassName=org.h2.Driver
spring.datasource.username=sa
spring.datasource.password=
spring.jpa.database-platform=org.hibernate.dialect.H2Dialect

# Email Configuration
spring.mail.host=smtp.gmail.com
spring.mail.port=587
spring.mail.username=your-email@gmail.com
spring.mail.password=your-email-password
spring.mail.properties.mail.smtp.auth=true
spring.mail.properties.mail.smtp.starttls.enable=true

Note: Use environment variables or a secrets manager for email credentials in production.

4. Create Entity Model

Step 4: Create `User` Entity

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

    // Constructors, Getters, and Setters
}

Step 5: Create `Question` Entity

@Entity
public class Question {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String title;
    private String url;
    private String difficulty;
}

5. Create Services

Step 6: Implement Email Service

@Service
public class EmailService {
    @Autowired
    private JavaMailSender mailSender;

    public void sendEmail(String to, String subject, String text) {
        SimpleMailMessage message = new SimpleMailMessage();
        message.setTo(to);
        message.setSubject(subject);
        message.setText(text);
        mailSender.send(message);
    }
}

Step 7: Implement Question Service

@Service
public class QuestionService {
    @Autowired
    private QuestionRepository questionRepository;

    public Question getRandomQuestion() {
        List<Question> questions = questionRepository.findAll();
        return questions.isEmpty() ? null : questions.get(new Random().nextInt(questions.size()));
    }
}

6. Implement Subscription System

Step 8: Create User Repository

@Repository
public interface UserRepository extends JpaRepository<User, Long> {
    Optional<User> findByEmail(String email);
}

Step 9: Create Subscription Controller

@RestController
@RequestMapping("/api/subscription")
public class SubscriptionController {
    @Autowired
    private UserRepository userRepository;

    @PostMapping("/subscribe")
    public String subscribe(@RequestParam String email) {
        if (userRepository.findByEmail(email).isPresent()) {
            return "You are already subscribed!";
        }
        userRepository.save(new User(email, true));
        return "Subscription successful!";
    }

    @PostMapping("/unsubscribe")
    public String unsubscribe(@RequestParam String email) {
        userRepository.findByEmail(email).ifPresent(user -> {
            user.setSubscribed(false);
            userRepository.save(user);
        });
        return "Unsubscribed successfully!";
    }
}

7. Implement Email Scheduler

Step 10: Schedule Daily Emails

@Component
public class EmailScheduler {
    @Autowired
    private QuestionService questionService;
    @Autowired
    private EmailService emailService;
    @Autowired
    private UserRepository userRepository;

    @Scheduled(cron = "0 30 19 * * ?") // Runs daily at 7:30 PM
    public void sendDailyQuestion() {
        Question question = questionService.getRandomQuestion();
        if (question != null) {
            String subject = "Daily LeetCode Question - " + question.getDifficulty();
            String body = "Today's question: " + question.getTitle() + "\n"
                        + "Solve it here: " + question.getUrl();

            List<User> subscribers = userRepository.findAll();
            for (User user : subscribers) {
                if (user.isSubscribed()) {
                    emailService.sendEmail(user.getEmail(), subject, body);
                }
            }
        }
    }
}

8. Test and Run the Application

Run Spring Boot Application

mvn spring-boot:run

Subscribe to the newsletter

curl -X POST "http://localhost:8080/api/subscription/subscribe?email=user@example.com"

Unsubscribe from the newsletter

curl -X POST "http://localhost:8080/api/subscription/unsubscribe?email=user@example.com"

Check email inbox at 7:30 PM