SoFunction
Updated on 2025-04-14

Use SpringBoot to realize the automatic sending of registration verification code emails

Preface

I've always been curious about how programs automatically send emails. Imagine that when you register on a website, you receive an email with a verification code shortly after entering your email address. This experience is both convenient and efficient. So, if we need a Spring Boot service that has the function of sending registration verification codes, how should we implement it? In this blog, I will start with demand analysis, gradually select technical models, introduce relevant APIs and principles, and finally give a specific implementation plan.

Requirements Analysis

Before implementing the function of sending registration verification codes, we need to clarify the requirements:

  • Functional Objectives: When a user registers, after entering the email address, the system generates a random verification code and sends it to the user via email.
  • Performance requirements: Emails should be sent as quickly as possible to avoid users waiting for a long time.
  • Security: The verification code needs to be random to avoid being easily guessed; the content of the email needs to protect user privacy.
  • User Experience: The content of the email should be concise and clear, including verification codes and necessary prompts.
  • Extensibility: In the future, other types of emails may need to be supported (such as password reset).

Based on these requirements, we need a reliable mail delivery mechanism, and combine the features of Spring Boot to simplify development.

Technical selection

Implementing the email sending function in Spring Boot, there are the following technical choices:

  • Spring Boot Starter Mail: The email sending module provided by Spring has built-in support for JavaMailSender and is simple to integrate.
  • Mail Service Provider: You can use third-party mail services (such as Gmail, QQ mailbox, Alibaba Cloud mail push, etc.) to send emails through the SMTP protocol.
  • Verification code generation: Using JavaRandomorUUIDGenerate a random verification code.

Considering the ecological support and development efficiency of Spring Boot, I chose to usespring-boot-starter-mailIt implements functions in conjunction with the SMTP service of QQ mailbox. The QQ mailbox is simple to configure and free to be available, suitable for development and testing.

Related APIs and principles

Core API

  • JavaMailSender
    • The email sending interface provided by Spring encapsulates the complexity of JavaMail.
    • passsend()Methods to send mail, support simple text messages and complex MIME messages.
  • MimeMessageHelper
    • It is used to construct complex email content (such as HTML formats, attachments, etc.), simplifying the email setup process.

How it works

  • SMTP protocol
    • Mail delivery is based on Simple Mail Transfer Protocol (SMTP). The client (Spring Boot application) sends the message to the target mailbox through an SMTP server (such as ).
    • The SMTP server address, port, username, and authorization code (rather than mailbox password) is required.
  • Spring Boot Integration
    • Spring Boot ByConfigure SMTP parameters and automatically injectJavaMailSenderBean, developers can send emails by simply calling the interface.

Implementation steps

1. Add dependencies

existIntroducing Spring Boot Mail module:

<dependency>
    <groupId></groupId>
    <artifactId>spring-boot-starter-mail</artifactId>
</dependency>

2. Configure the email service

existSMTP parameters for the QQ mailbox are configured:

=
=587
=yourQQMail@
=your授权码
=true
=true

Note: password is not the email password, but the authorization code generated by the QQ mailbox. It needs to be enabled in the SMTP service in the QQ mailbox settings.

3. Implement verification code generation and email sending

Create a service class to handle verification code generation and mail sending logic:

import ;
import ;
import ;
import ;

import ;
import ;
import ;

@Service
public class EmailService {

    @Autowired
    private JavaMailSender mailSender;

    // Generate 6-bit random verification code    public String generateVerificationCode() {
        Random random = new Random();
        int code = 100000 + (900000); // Range 100000-999999        return (code);
    }

    // Send registration verification code email    public void sendVerificationEmail(String toEmail, String code) throws MessagingException {
        MimeMessage message = ();
        MimeMessageHelper helper = new MimeMessageHelper(message, true);

        ("Your QQ Email @"); // Sender        (toEmail); // recipient        ("Register verification code"); // Email Subject        ("<h3>Your registration verification code is:" + code + "</h3><p>Please use it within 5 minutes, this verification code is only used for registration.</p>", true); // HTML content
        (message);
    }
}

4. Create Controller Call Service

Receive user requests and call them in ControllerEmailService：

import ;
import ;
import ;
import ;

import ;

@RestController
public class RegisterController {

    @Autowired
    private EmailService emailService;

    @PostMapping("/register/send-code")
    public String sendVerificationCode(@RequestParam String email) {
        try {
            String code = ();
            (email, code);
            return "Verification code sent to" + email;
        } catch (MessagingException e) {
            return "Send failed:" + ();
        }
    }
}

5. Test

Start the Spring Boot application and use a tool such as Postman to send a POST request to/register/send-code, the parameters areemail=target email address, check whether the target email has received the verification code email.

Summarize

Through the above steps, we have implemented a Spring Boot-based registration verification code email sending function. From demand analysis to technical selection, to specific implementation, the entire process demonstrates the simplicity of Spring Boot and the power of JavaMailSender. In the future, we can further improve security and user experience by adding Redis cache verification code and validity verification.

If you are also curious about how the program automatically sends emails, you might as well try this solution!

The above is the detailed content of using SpringBoot to realize the automatic sending of registration verification code emails. For more information about sending registration verification code emails in SpringBoot, please pay attention to my other related articles!