在Spring boot中发送包含多个附件的电子邮件

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.mail.MailProperties;
import org.springframework.boot.autoconfigure.mail.MailSenderAutoConfiguration;
import org.springframework.core.io.ByteArrayResource;
import org.springframework.core.io.FileSystemResource;
import org.springframework.mail.javamail.JavaMailSender;
import org.springframework.mail.javamail.MimeMessageHelper;
import org.springframework.mail.javamail.MimeMessagePreparator;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.mail.MessagingException;
import javax.mail.internet.MimeMessage;
import java.io.File;

@SpringBootApplication(exclude = MailSenderAutoConfiguration.class)
@RestController
public class EmailApplication {

    @Autowired
    private JavaMailSender mailSender;

    @Autowired
    private MailProperties mailProperties;

    public static void main(String[] args) {
        SpringApplication.run(EmailApplication.class, args);
    }

    @GetMapping("/sendEmail")
    public void sendEmail() throws MessagingException {
        mailSender.send(new MimeMessagePreparator() {
            @Override
            public void prepare(MimeMessage mimeMessage) throws Exception {
                MimeMessageHelper helper = new MimeMessageHelper(mimeMessage, true);

                helper.setFrom(mailProperties.getUsername());
                helper.setTo("recipient@example.com");
                helper.setSubject("Email with attachments");
                helper.setText("Please see the attached files.");

                // 添加第一个附件
                File attachment1 = new File("path/to/attachment1.txt");
                helper.addAttachment("attachment1.txt", attachment1);

                // 添加第二个附件
                byte[] attachmentData = "Hello, World!".getBytes();
                ByteArrayResource attachment2 = new ByteArrayResource(attachmentData);
                helper.addAttachment("attachment2.txt", attachment2);

                // 添加第三个附件
                File attachment3 = new File("path/to/attachment3.pdf");
                helper.addAttachment("attachment3.pdf", new FileSystemResource(attachment3));
            }
        });
    }
}