How do I send an HTML email?

The following code snippets show you how to send an html e-mail. We begin by defining the e-mail information such as the from address, to address and the subject. The next step it to create a Properties that will be used to create a mail Session object. Having a Session object we can then create a Message using the MimeMessage.

We use the MimeMessage.setContent(Object, String) to set the html content of the email. Do not forget to set the content type to text/html and also supply the character set, in the example we use charset=utf-8.

package org.kodejava.example.mail;

import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import java.util.Properties;

public class SendHTMLEmail {
    public static void main(String[] args) {
        String from = "[email protected]";
        String to = "[email protected]";
        String subject = "Hello";

        Properties props = new Properties();
        props.put("mail.smtp.host", "smtp.gmail.com");
        props.put("mail.transport.protocol", "smtp");
        props.put("mail.smtp.starttls.enable", "true");
        Session session = Session.getDefaultInstance(props);

        try {
            InternetAddress fromAddress = new InternetAddress(from);
            InternetAddress toAddress = new InternetAddress(to);

            Message message = new MimeMessage(session);
            message.setFrom(fromAddress);
            message.setRecipient(Message.RecipientType.TO, toAddress);
            message.setSubject(subject);

            String sb = "<head>" +
                    "<style type=\"text/css\">" +
                    "  .red { color: #f00; }" +
                    "</style>" +
                    "</head>" +
                    "<h1 class=\"red\">" + message.getSubject() + "</h1>" +
                    "<p>" +
                    "Lorem ipsum dolor sit amet, <em>consectetur</em> adipisicing elit, sed do " +
                    "eiusmod tempor incididunt ut labore et dolore magna <strong>aliqua</strong>." +
                    "</p>";
            message.setContent(sb, "text/html; charset=utf-8");
            message.saveChanges();

            // Send the message to the recipient. You also need to specify the username and
            // password to authenticate to the mail server.
            Transport.send(message, "kodejava", "**********");
        } catch (MessagingException e) {
            e.printStackTrace();
        }
    }
}

How do I format JLabel using HTML?

JLabel text can be formatted using an HTML standard tags. The example below shows you how we can use and HTML font tag to change the font size, color and style of JLabel text.

package org.kodejava.example.swing;

import javax.swing.*;
import java.awt.*;

public class HTMLLabel extends JFrame {
    public HTMLLabel() {
        setTitle("JLabel with HTML");
        initComponents();
    }

    private void initComponents() {
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        setSize(400, 200);
        Container container = getContentPane();
        container.setLayout(new FlowLayout(FlowLayout.CENTER));

        // Create a JLabel object that display a string formatted using HTML.
        // 14 font size with red and italic.
        String text = "<html><font size=\"14\" color=\"ff0000\"><i>Hello World</i></font></html>";
        JLabel label = new JLabel(text);
        container.add(label);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> new HTMLLabel().setVisible(true));
    }
}