JTextPane setContentType("text/html")

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package javaapplication37;

import java.util.Set;
import javax.swing.JFrame;
import javax.swing.JTextPane;

/**
 *
 * @author leo
 */
public class JavaApplication37 extends JFrame {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        JTextPane textPane = new JTextPane(); // creates an empty text pane
        textPane.setContentType("text/html"); // lets Java know it will be HTML
        textPane.setText("<u><span style = 'font-size: 20pt'> Big </span ></u>"); // sets its text
        JFrame frame = new JFrame(); // makes a window to put it in
        frame.getContentPane().add(textPane); // adds the text pane to the window
        frame.pack(); // adjusts the window to the right size
        frame.setVisible(true); // makes it show up
    }
}