EmailService Class

EmailService.java

@Service
@RequiredArgsConstructor
public class EmailService {
    private final JavaMailSender emailSender;

    @Value("${application.mail.sent.from}")
    private String fromUsr;

    public void sendEmail(String to, String subject, String body) throws MessagingException {
        MimeMessage message = emailSender.createMimeMessage();
        MimeMessageHelper helper = new MimeMessageHelper(message, true, "UTF-8");
        helper.setTo(to);
        helper.setFrom(fromUsr);
        helper.setSubject(subject);
        helper.setText(body, true);
        emailSender.send(message);
    }

    @RabbitListener(queues = "email_queue")
    public void processEmailMessage(EmailDetailDTO emailDetailDTO) throws MessagingException {
        String to = emailDetailDTO.getTo();
        String subject = emailDetailDTO.getSubject();
        String body = generateEmailBody(emailDetailDTO);
        sendEmail(to, subject, body);
    }

    public String generateEmailBody(EmailDetailDTO emailDetailDTO) {
        String templateName = emailDetailDTO.getTemplateName();
        String template = loadEmailTemplate(templateName);

        String body = template;
        if (emailDetailDTO.getDynamicValue() != null) {
            for (Map.Entry<String, Object> entry : emailDetailDTO.getDynamicValue().entrySet()) {
                body = body.replace("{{" + entry.getKey() + "}}", entry.getValue().toString());
            }
        }

        return body;
    }

    public String loadEmailTemplate(String templateName) {
        ClassPathResource resource = new ClassPathResource("templates/emails/" + templateName + ".html");
        try {
            return StreamUtils.copyToString(resource.getInputStream(), StandardCharsets.UTF_8);
        } catch (IOException e) {
            throw new RuntimeException("Error loading email template " + templateName, e);
        }
    }
}