Basic Text Components - The Definitive Guide to Java Swing - page 561

JTextArea Class
The JTextArea component is the text component for multiple-line input. Similar to the
JTextField , the data model for a JTextArea is the PlainDocument implementation of the
Document interface. Therefore, the JTextArea is limited to single-attributed text. As with other
Swing components that may require scrolling, the JTextArea doesn't support scrolling itself.
You need to place each JTextArea within a JScrollPane to allow a user to properly scroll through
the contents of a JTextArea .

Creating a JTextArea
There are six constructors for creating a JTextArea :

public JTextArea()
JTextArea textArea = new JTextArea();

public JTextArea(Document document)
Document document = new PlainDocument();
JTextArea textArea = new JTextArea(document);

public JTextArea(String text)
JTextArea textArea = new JTextArea("...");

public JTextArea(int rows, int columns)
JTextArea textArea = new JTextArea(10, 40);

public JTextArea(String text, int rows, int columns)
JTextArea textArea = new JTextArea("...", 10, 40);

public JTextArea(Document document, String text, int rows, int columns)
JTextArea textArea = new JTextArea(document, null, 10, 40);

Unless otherwise specified, the text area is able to hold zero rows and columns of content.
Although this might sound like a serious limitation, you're just telling the text area to let the
current LayoutManager worry about the size of your text area. The contents of the JTextArea are
initially empty unless specified from either the starting text string or the Document model.

■ Note Other initial settings for a JTextArea include having a tab stop every eight positions and turning off

word wrap. For more on tab stops, see the TabStop and TabSet class descriptions in Chapter 16.

After creating a JTextArea , remember to place the JTextArea into a JScrollPane . Then if
there isn't sufficient space on the screen, the JScrollPane will manage the scrolling for you.