使用spring boot和并行流发送电子邮件

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.mail.SimpleMailMessage;
import org.springframework.mail.javamail.JavaMailSender;
import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Component;

import java.util.List;
import java.util.stream.Collectors;

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

    @Async
    public void sendEmails(List<String> recipients, String subject, String content) {
        List<SimpleMailMessage> messages = recipients.stream()
                .map(recipient -> createEmailMessage(recipient, subject, content))
                .collect(Collectors.toList());

        messages.parallelStream().forEach(mailSender::send);
    }

    private SimpleMailMessage createEmailMessage(String recipient, String subject, String content) {
        SimpleMailMessage message = new SimpleMailMessage();
        message.setTo(recipient);
        message.setSubject(subject);
        message.setText(content);
        return message;
    }
}