java 实现带excel发邮件

以下是Java实现带Excel发邮件的示例代码：

import java.io.File;
import java.util.Properties;

import javax.activation.DataHandler;
import javax.activation.FileDataSource;
import javax.mail.BodyPart;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.Multipart;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;

public class SendEmailWithExcel {

    public static void main(String[] args) {
        String to = "recipient@example.com";
        String from = "sender@example.com";
        String host = "smtp.example.com";
        String subject = "Email with Excel attachment";

        // Get system properties
        Properties properties = System.getProperties();

        // Setup mail server
        properties.setProperty("mail.smtp.host", host);

        // Get the default Session object.
        Session session = Session.getDefaultInstance(properties);

        try {
            // Create a default MimeMessage object.
            MimeMessage message = new MimeMessage(session);

            // Set From: header field of the header.
            message.setFrom(new InternetAddress(from));

            // Set To: header field of the header.
            message.addRecipient(Message.RecipientType.TO, new InternetAddress(to));

            // Set Subject: header field
            message.setSubject(subject);

            // Create the message part
            BodyPart messageBodyPart = new MimeBodyPart();

            // Fill the message
            messageBodyPart.setText("This email contains an Excel attachment.");

            // Create a multipart message
            Multipart multipart = new MimeMultipart();

            // Set text message part
            multipart.addBodyPart(messageBodyPart);

            // Part two is attachment
            messageBodyPart = new MimeBodyPart();
            String filename = "example.xlsx";
            File file = new File(filename);
            FileDataSource dataSource = new FileDataSource(file);
            messageBodyPart.setDataHandler(new DataHandler(dataSource));
            messageBodyPart.setFileName(file.getName());
            multipart.addBodyPart(messageBodyPart);

            // Send the complete message parts
            message.setContent(multipart);

            // Send message
            Transport.send(message);
            System.out.println("Email sent successfully.");
        } catch (MessagingException e) {
            System.out.println("Failed to send email. Error message: " + e.getMessage());
        }
    }

}

在上面的代码中，我们使用JavaMail API来创建一个带有Excel附件的电子邮件。我们首先设置邮件服务器和收件人、发件人和主题。然后，我们创建一个MimeMessage对象，并使用MimeMultipart对象来创建一个多部分消息。该消息包括一个文本消息和一个Excel附件。最后，我们将消息的内容设置为多部分消息，并使用Transport类的send()方法将其发送。

请注意，为了使此代码正常工作，您需要在classpath中包含JavaMail和Java Activation Framework库。