How to enable attachment using Apache File upload

Question

I am using Apache commons File upload API to Store the file from JSP to servlets in temp directory, but I don't know what should I do next to send the email as an attachment using javamail API.

How can I retrieve those files which is written in temp directory using Apache Fileupload API to send them as attachment to mail Server. How will writing those files either to memory or disk will help me?

Answer 1

Here is a example:

private static void notify(String subject, String text,
        File attachment, String from, String to) throws Exception {
    Context context = new InitialContext();
    Session sess = (Session)context.lookup("java:comp/env/mail/session");
    MimeMessage message = new MimeMessage(sess);
    message.setSubject(subject, "UTF-8");
    if (attachment == null) {
        message.setText(text, "UTF-8");
    } else {
        MimeMultipart mp = null;
        MimeBodyPart part1 = new MimeBodyPart();
        part1.setText(text, "UTF-8");
        MimeBodyPart part2 = new MimeBodyPart();
        part2.setDataHandler(new DataHandler(new FileDataSource(attachement)));
        part2.setFileName(file.getName());
        mp = new MimeMultipart();
        mp.addBodyPart(part1);
        mp.addBodyPart(part2);
        message.setContent(mp);
   }

    message.setFrom(new InternetAddress(from));
    message.addRecipient(Message.RecipientType.TO, new InternetAddress(to));
    Transport.send(message);
}

In this example, a FileDataSource is used, which means that the attachment must first be saved as a file. I sometimes use a home-brewed MemoryDataSource instead. Here is the code:

package com.lagalerie.mail;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.io.OutputStream;

import javax.activation.DataSource;

public class MemoryDataSource implements DataSource {
    private String name;
    private String contentType;
    private byte content[] = {};

    public MemoryDataSource(String name, String contentType) {
        this.name = name;
        this.contentType = contentType;
    }

    public String getContentType() {
        return contentType;
    }

    public InputStream getInputStream() {
        return new ByteArrayInputStream(content);
    }

    public String getName() {
        return name;
    }

    public OutputStream getOutputStream() {
        return new ByteArrayOutputStream() {
            @Override
            public void close() {
                content = toByteArray();
            }
        };
    }
}