package javacodebook.misc.mail_attach;

import javax.mail.*;
import javax.mail.internet.*;
import javax.activation.*;
import java.util.Date;
import java.util.Properties;
import java.io.*;

/**
 * Diese Klasse dient zum Versenden einer einfachen Mail. Die Mail hat ein
 * Attachment, kann aber nicht an Personen im CC oder BCC versendet werden.
 */
public class AttachmentMailSender {

    // Die Daten, die zum Versand eine Mail benötigt werden.
    String recipient  = null;
    String sender     = null;
    String subject    = null;
    String text       = null;
    String host       = null;
    File   attachment = null;

    public AttachmentMailSender() {
    }

    public void setHost(String host) {
        this.host = host;
    }

    public void setRecipient(String recipient) {
        this.recipient = recipient;
    }

    public void setSender(String sender) {
        this.sender = sender;
    }

    public void setSubject(String subject) {
        this.subject = subject;
    }

    public void setText(String text) {
        this.text = text;
    }

    public void setAttachment(File attachment) {
        this.attachment = attachment;
    }

    /**
     * Versendet die Nachricht. Treten dabei Probleme auf, werden diese in Form
     * einer Exception an die aufrufende Instanz weitergeleitet.
     */
    public void sendMessage() throws AddressException, MessagingException {

        // Der SMTP-Host, über den die Mails gesendet werden, wird in der Liste
        // der Porperties angegeben.
        Properties props = new Properties();
        props.put("mail.smtp.host", host);

        // Es wird eine Mail-Session angelegt. Über diese Session erfolgt der
        // Versand.
        Session session = Session.getDefaultInstance(props, null);

        // Nachricht erzeugen, Adressat, Absender und Betreff angeben.
        MimeMessage msg = new MimeMessage(session);
        msg.setFrom(new InternetAddress(sender));
        InternetAddress[] address = {new InternetAddress(recipient)};
        msg.setRecipients(Message.RecipientType.TO, address);
        msg.setSubject(subject);
        msg.setSentDate(new Date());

        if (attachment != null)
        {
            // Der Text als erster Part
            MimeBodyPart mbp1 = new MimeBodyPart();
            mbp1.setText(text);

            // Das Attachment als zweiter Part
            MimeBodyPart mbp2 = new MimeBodyPart();
            FileDataSource fds = new FileDataSource(attachment);
            mbp2.setDataHandler(new DataHandler(fds));
            mbp2.setFileName(fds.getName());

            // Die beiden Teile als Multipart zusammenfügen
            Multipart mp = new MimeMultipart();
            mp.addBodyPart(mbp1);
            mp.addBodyPart(mbp2);

            // Den Multipart an die Nachricht hängen
            msg.setContent(mp);
        }
        else
            msg.setText(text);

        // Die Nachricht versenden.
        Transport.send(msg);
    }
}

--- Neue Klasse ---

package javacodebook.misc.mail_attach;

import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
import java.io.File;

public class MailSendFrame extends JFrame implements ActionListener {


    public static void main(String []args) {
            (new MailSendFrame()).show();
    }

    public MailSendFrame() {
        super();
        initComponents();
    }

    /**
     * Das GUI-Layout erzeugen
     */
    private void initComponents() {
        buttons          = new JPanel();
        send             = new JButton("Senden");
        cancel           = new JButton("Abbrechen");
        main             = new JPanel();
        labelHost        = new JLabel("SMTP-Host:");
        labelSender      = new JLabel("Absender:");
        labelRecipient   = new JLabel("Empf\u00e4nger:");
        labelSubject     = new JLabel("Betreff:");
        labelAttachment  = new JLabel("Attachment:");
        inputHost        = new JTextField();
        inputSender      = new JTextField();
        inputRecipient   = new JTextField();
        inputSubject     = new JTextField();
        inputAttachment  = new JTextField();
        inputText        = new JTextArea();
        scrollText       = new JScrollPane();
        buttonAttachment = new JButton("...");

        main.setLayout(new GridBagLayout());
        GridBagConstraints gridBagConstraints;

        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 0;
        gridBagConstraints.insets = new Insets(2, 5, 3, 5);
        gridBagConstraints.anchor = GridBagConstraints.WEST;
        main.add(labelHost, gridBagConstraints);

        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 1;
        gridBagConstraints.insets = new Insets(2, 5, 3, 5);
        gridBagConstraints.anchor = GridBagConstraints.WEST;
        main.add(labelSender, gridBagConstraints);

        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 2;
        gridBagConstraints.insets = new Insets(2, 5, 3, 5);
        gridBagConstraints.anchor = GridBagConstraints.WEST;
        main.add(labelRecipient, gridBagConstraints);

        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 3;
        gridBagConstraints.insets = new Insets(2, 5, 3, 5);
        gridBagConstraints.anchor = GridBagConstraints.WEST;
        main.add(labelSubject, gridBagConstraints);

        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 4;
        gridBagConstraints.insets = new Insets(2, 5, 3, 5);
        gridBagConstraints.anchor = GridBagConstraints.WEST;
        main.add(labelAttachment, gridBagConstraints);

        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 1;
        gridBagConstraints.gridy = 0;
        gridBagConstraints.gridwidth = 2;
        gridBagConstraints.fill = GridBagConstraints.HORIZONTAL;
        gridBagConstraints.insets = new Insets(2, 0, 3, 5);
        gridBagConstraints.anchor = GridBagConstraints.WEST;
        gridBagConstraints.weightx = 1.0;
        main.add(inputHost, gridBagConstraints);

        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 1;
        gridBagConstraints.gridy = 1;
        gridBagConstraints.gridwidth = 2;
        gridBagConstraints.fill = GridBagConstraints.HORIZONTAL;
        gridBagConstraints.insets = new Insets(2, 0, 3, 5);
        gridBagConstraints.anchor = GridBagConstraints.WEST;
        gridBagConstraints.weightx = 1.0;
        main.add(inputSender, gridBagConstraints);

        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 1;
        gridBagConstraints.gridy = 2;
        gridBagConstraints.gridwidth = 2;
        gridBagConstraints.fill = GridBagConstraints.HORIZONTAL;
        gridBagConstraints.insets = new Insets(2, 0, 3, 5);
        gridBagConstraints.anchor = GridBagConstraints.WEST;
        gridBagConstraints.weightx = 1.0;
        main.add(inputRecipient, gridBagConstraints);

        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 1;
        gridBagConstraints.gridy = 3;
        gridBagConstraints.gridwidth = 2;
        gridBagConstraints.fill = GridBagConstraints.HORIZONTAL;
        gridBagConstraints.insets = new Insets(2, 0, 3, 5);
        gridBagConstraints.anchor = GridBagConstraints.WEST;
        gridBagConstraints.weightx = 1.0;
        main.add(inputSubject, gridBagConstraints);

        inputAttachment.setEditable(false);
        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 1;
        gridBagConstraints.gridy = 4;
        gridBagConstraints.fill = GridBagConstraints.HORIZONTAL;
        gridBagConstraints.insets = new Insets(2, 0, 3, 5);
        gridBagConstraints.anchor = GridBagConstraints.WEST;
        gridBagConstraints.weightx = 1.0;
        main.add(inputAttachment, gridBagConstraints);

        buttonAttachment.setActionCommand("attachment");
        buttonAttachment.addActionListener(this);

        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 2;
        gridBagConstraints.gridy = 4;
        gridBagConstraints.fill = GridBagConstraints.HORIZONTAL;
        gridBagConstraints.insets = new Insets(2, 0, 3, 5);
        gridBagConstraints.anchor = GridBagConstraints.WEST;
        main.add(buttonAttachment, gridBagConstraints);

        inputText.setLineWrap(true);
        inputText.setWrapStyleWord(true);
        inputText.setColumns(40);
        inputText.setRows(10);
        scrollText.setViewportView(inputText);

        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 5;
        gridBagConstraints.gridwidth = 3;
        gridBagConstraints.fill = GridBagConstraints.BOTH;
        gridBagConstraints.insets = new Insets(0, 5, 0, 5);
        gridBagConstraints.weightx = 1.0;
        gridBagConstraints.weighty = 1.0;
        main.add(scrollText, gridBagConstraints);

        setTitle("Neue Nachricht");

        send.setMnemonic('S');
        send.setActionCommand("send");
        send.addActionListener(this);
        buttons.add(send);

        cancel.setMnemonic('A');
        cancel.setActionCommand("cancel");
        cancel.addActionListener(this);
        buttons.add(cancel);

        getContentPane().add(buttons, BorderLayout.SOUTH);
        getContentPane().add(main, BorderLayout.CENTER);

        pack();
    }

    /**
     * Vesenden der Mail, wenn der Benutzer den "Senden"-Button gedrückt hat,
     * bzw. Beenden des Programmes, wenn er "Abbrechen" gedrückt hat.
     */
    public void actionPerformed(ActionEvent evt) {
        if (evt.getActionCommand().equals("send")) {
            AttachmentMailSender ams = new AttachmentMailSender();
            ams.setHost(inputHost.getText());
            ams.setRecipient(inputRecipient.getText());
            ams.setSender(inputSender.getText());
            ams.setSubject(inputSubject.getText());
            ams.setText(inputText.getText());
            ams.setAttachment(attachment);
            try {
                ams.sendMessage();
                System.exit(0);
            }
            catch (Exception e) {
                JOptionPane.showMessageDialog(
                this,
                "Mail konnte nicht versendet werden!\n" +
                "Fehler: " + e.getMessage(),
                "Fehler beim Versenden",
                JOptionPane.ERROR_MESSAGE
                );
            }
        }
        else if (evt.getActionCommand().equals("attachment")) {
            try {
                JFileChooser chooser = new JFileChooser();
                int returnVal = chooser.showOpenDialog(this);
                if(returnVal == JFileChooser.APPROVE_OPTION) {
                    attachment = chooser.getSelectedFile();
                    inputAttachment.setText(attachment.getName());
                }
            }
            catch (Exception e) {}
        }
        else
            System.exit(0);
    }

    // Variablendeklaration
    private JButton     send;
    private JButton     cancel;
    private JPanel      buttons;
    private JPanel      main;
    private JTextField  inputSender;
    private JTextField  inputRecipient;
    private JTextField  inputSubject;
    private JTextField  inputHost;
    private JTextField  inputAttachment;
    private JScrollPane scrollText;
    private JTextArea   inputText;
    private JLabel      labelHost;
    private JLabel      labelSubject;
    private JLabel      labelSender;
    private JLabel      labelRecipient;
    private JLabel      labelAttachment;
    private JButton     buttonAttachment;

    private File        attachment;
}