使用spring boot下载邮件中CSV文件的链接

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-mail</artifactId>
</dependency>

spring.mail.host=smtp.example.com
spring.mail.port=587
spring.mail.username=your-email@example.com
spring.mail.password=your-password

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.mail.MailProperties;
import org.springframework.core.io.InputStreamSource;
import org.springframework.mail.javamail.JavaMailSender;
import org.springframework.mail.javamail.MimeMessageHelper;
import org.springframework.stereotype.Service;

import javax.mail.MessagingException;
import javax.mail.internet.MimeMessage;
import java.io.IOException;
import java.io.InputStream;

@Service
public class EmailService {

    @Autowired
    private JavaMailSender mailSender;

    @Autowired
    private MailProperties mailProperties;

    public void sendEmailWithAttachment(String to, String subject, String text, InputStreamSource attachment, String attachmentName) throws MessagingException, IOException {
        MimeMessage message = mailSender.createMimeMessage();
        MimeMessageHelper helper = new MimeMessageHelper(message, true);

        helper.setFrom(mailProperties.getUsername());
        helper.setTo(to);
        helper.setSubject(subject);
        helper.setText(text);

        helper.addAttachment(attachmentName, attachment);

        mailSender.send(message);
    }
}

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.InputStreamResource;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.mail.MessagingException;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;

@RestController
public class DownloadController {

    @Autowired
    private EmailService emailService;

    @GetMapping("/download")
    public ResponseEntity<InputStreamResource> downloadCSV() throws MessagingException, IOException {
        // 发送邮件并获取附件
        String to = "recipient@example.com";
        String subject = "CSV File";
        String text = "Please find the attached CSV file.";
        InputStreamSource attachment = getCSVFile(); // 获取CSV文件的输入流
        String attachmentName = "data.csv";

        emailService.sendEmailWithAttachment(to, subject, text, attachment, attachmentName);

        // 构建响应
        byte[] data = attachment.getInputStream().readAllBytes();
        InputStreamResource resource = new InputStreamResource(new ByteArrayInputStream(data));

        return ResponseEntity.ok()
                .header(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=" + attachmentName)
                .contentType(MediaType.APPLICATION_OCTET_STREAM)
                .contentLength(data.length)
                .body(resource);
    }

    private InputStreamSource getCSVFile() {
        // 从邮件或其他地方获取CSV文件的输入流
        // 这里只是一个示例，你可以根据实际情况来获取输入流
        String csvData = "id,name,age\n1,John,25\n2,Jane,30";
        return new InputStreamResource(new ByteArrayInputStream(csvData.getBytes()));
    }
}