The JTextField Class
JTextField allows the user to enter a single line of text, scrolling the text if its size exceeds the physical size of the field. A JTextField fires an ActionEvent to any registered ActionListeners (including the Action set via the setAction( ) method, if any) when the user presses the Enter key.
JTextFields (and all JTextComponents) are automatically installed with a number of behaviors appropriate to the L&F, so cut/copy/paste, special cursor movement keys, and text-selection gestures should work without any extra intervention on your part.
import javax.swing.*;
import java.awt.event.*;
public class JTextFieldExample {
public static void main(String[] args) {
final JTextField tf = new JTextField("press <enter>", 20);
tf.setHorizontalAlignment(JTextField.RIGHT);
tf.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
int old = tf.getHorizontalAlignment();
if (old == JTextField.LEFT)
tf.setHorizontalAlignment(JTextField.RIGHT);
if (old == JTextField.RIGHT)
tf.setHorizontalAlignment(JTextField.CENTER);
if (old == JTextField.CENTER)
tf.setHorizontalAlignment(JTextField.LEFT);
}
});
JFrame frame = new JFrame("JTextFieldExample");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(new java.awt.FlowLayout());
frame.getContentPane().add(tf);
frame.setSize(275, 75);
frame.setVisible(true);
tf.requestFocus();
}
}
