import javax.swing.Icon; import javax.swing.ImageIcon; import javax.swing.JFrame; import javax.swing.JOptionPane; import javax.swing.JDialog; import javax.swing.JOptionPane; public class DisplayingMultilineMessages { public static void main(String[] a) { String msg = "<html>this is a really long message<br>this is a really long message this is a really long message this is a really long message this is a really long message this is a really long message this is a really long message"; JOptionPane optionPane = new NarrowOptionPane(); optionPane.setMessage(msg); optionPane.setMessageType(JOptionPane.INFORMATION_MESSAGE); JDialog dialog = optionPane.createDialog(null, "Width 100"); dialog.setVisible(true); } } class NarrowOptionPane extends JOptionPane { NarrowOptionPane() { } public int getMaxCharactersPerLineCount() { return 100; } }