Swing I - Java - page 941

The method getText is an input method, and the method setText is an output
method. The method setText can be used to display a new text string in a text field.
For example, the following will cause the text field name to change the text it displays
to the string "This is some output" :

name.setText("This is some output");

The following line from the method actionPerformed in Display 17.17 uses both
getText and setText :

name.setText("Hello " + name.getText());

This line changes the string in the text field name to "Hello " followed by the old
string value in the text field. The net effect is to insert the string "Hello " in front of
the string displayed in the text field.

getText and setText
The classes JTextField and JTextArea both contain methods called getText and set-
Text . The method getText can be used to retrieve the text written in the text field or text
area. The method setText can be used to change the text written in the text field or text
area.
SYNTAX
Name_of_Text_Component .getText() returns the text currently displayed in the text field
or text area.
Name_of_Text_Component .setText( New_String_To_Display );

EXAMPLES
String inputString = ioComponent.getText();
ioComponent.setText("Hello out there!");

ioComponent may be an instance of either of the classes JTextField or JTextArea .

A text area is an object of the class JTextArea . A text area is the same as a text field
except that it allows multiple lines. Two parameters to the constructor for JTextArea
specify the minimum number of lines and the minimum number of characters per line
that are guaranteed to be visible. You can enter any amount of text in a text area, but
only a limited number of lines and a limited number of characters per line will be visi-
ble. For example, the following creates a JTextArea named theText that will have at
least 5 lines and at least 20 characters per line visible:

text area
JTextArea

JTextArea theText = new JTextArea(5, 20);