创建CSV文件并作为附件发送

Question

So I'm trying to generate a csv file and then immediately send it as an attachment.

@Async
public void sendAuditEventsReportEmail(@NonNull Locale locale,
                                       @NonNull String fileName,
                                       @NonNull String[] contacts,
                                       @NonNull List<AuditEventResponse> auditEventResponses) {
    try {

        final MimeMessageHelper message = message(true);
        message.setFrom(portalProperties.getMail().getFrom());
        message.setCc(contacts);
        message.setSubject(messageSource.getMessage("mail.act.subject", null, locale)
                           + fileName);
        writeCSVFile(fileName, auditEventResponses);
        message.addInline("customer-logo",
                          new ClassPathResource(CUSTOMER_LOGO_PATH),
                          PNG_MIME);
        this.mailSender.send(message.getMimeMessage());

    } catch (MessagingException e) {
        log.error("Could not send audit report email");
    }
}

private void writeCSVFile(String fileName, List<AuditEventResponse> auditEventResponses) {
    ICsvBeanWriter beanWriter = null;
    try {
        beanWriter = new CsvBeanWriter(new FileWriter(fileName + ".csv"),
                                       CsvPreference.STANDARD_PREFERENCE);
        String[] header = {"type", "entityType", "principal", "timestamp", "data", "date"};
        beanWriter.writeHeader(header);
        for (AuditEventResponse auditEventResponse : auditEventResponses) {
            beanWriter.write(auditEventResponse, header);
        }
    } catch (IOException e) {
        System.err.println("Error writing the CSV file: " + e);
    } finally {
        if (beanWriter != null) {
            try {
                beanWriter.close();
            } catch (IOException e) {
                System.err.println("Error closing the writer: " + e);
            }
        }
    }
}

but as you can see, I'm only creating the file (wanted to make sure it was generated correctly). Is there a way to generate the file in memory so that I can use it as an attachment in the email? I think the library I'm using doesn't support it (supercsv) are there any others that can do the same but in memory? Thanks in advance!

Answer 1

If you need to send an attachment, you'll have to create physically a file, so the way you are doing your program is good. You just have to delete your file after sending your mail.