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import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import javax.swing.JFrame;
import javax.swing.JTextField;
public class UsingFocusListener {
public static void main(String[] a) {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JTextField textField = new JTextField("A TextField");
textField.addFocusListener(new FocusListener() {
public void focusGained(FocusEvent e) {
displayMessage("Focus gained", e);
}
public void focusLost(FocusEvent e) {
displayMessage("Focus lost", e);
}
void displayMessage(String prefix, FocusEvent e) {
System.out.println(prefix
+ (e.isTemporary() ? " (temporary):" : ":")
+ e.getComponent().getClass().getName()
+ "; Opposite component: "
+ (e.getOppositeComponent() != null ? e.getOppositeComponent().getClass().getName()
: "null"));
}
});
frame.add(textField,"North");
frame.add(new JTextField(),"South");
frame.setSize(300, 200);
frame.setVisible(true);
}
}
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