JTextPane is a Swing component in Java that provides a text editor pane that can display and edit styled text. JTextPane can handle text in various formats including plain text, HTML, and RTF (Rich Text Format).

JTextPane extends JEditorPane and adds support for the StyledDocument interface, which allows you to add styles to the text displayed in the pane. You can use JTextPane to create a rich text editor with features such as different font sizes and colors, bold and italic styles, bullet lists, images, and tables.

To create a JTextPane object, you can use the following code:

JTextPane textPane = new JTextPane();

You can add text to the JTextPane by getting its document and adding the text to it:

StyledDocument doc = textPane.getStyledDocument();
doc.insertString(0, "Hello, world", null);

The insertString method inserts the given string at the specified position in the document. The third argument is an AttributeSet that can be used to specify the style of the text. If you pass null, the text will use the default style.

You can add styles to the text in the JTextPane by creating an instance of the SimpleAttributeSet class and setting its attributes. For example, the following code sets the text to red and bold:

StyledDocument doc = textPane.getStyledDocument();
SimpleAttributeSet redBold = new SimpleAttributeSet();
StyleConstants.setForeground(redBold, Color.RED);
StyleConstants.setBold(redBold, true);
doc.insertString(0, "Hello, world", redBold);

JTextPane supports copy and paste operations, as well as undo and redo. You can use the JTextPane in combination with other Swing components to create a text editor with menus and toolbars.