import javax.swing.JTextPane; import javax.swing.text.Style; import javax.swing.text.StyleConstants; import javax.swing.text.StyledDocument; public class Main { public static void main(String[] argv) throws Exception{ JTextPane textPane = new JTextPane(); StyledDocument doc = (StyledDocument) textPane.getDocument(); Style style = doc.addStyle("StyleName", null); StyleConstants.setItalic(style, true); doc.insertString(doc.getLength(), "Some Text", style); } }