CircleFrame

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class CircleFrame extends JFrame implements ActionListener,
    KeyListener {

    public CircleFrame() {
        super("Circle Calculator");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JTextField radius = new JTextField(
            "Radius", 12);
            radius.addKeyListener(this);
        JPanel panel = new JPanel();
        panel.add(radius);
        add(panel);
        pack();
        setVisible(true);
    }

    public void keyReleased(KeyEvent keyPressed) {
        Object source = event.getSource();
        if (source instanceof JTextField) {
            double inputRadius = input.getText();
            output1 = inputRadius * 2;
            output2 = output1 * 3.14;
            break;
        }
    }

    JMenu output = newJMenu("Output");
    JMenuItem out1 = new JMenuItem(output1 + " is the radius");
    JMenuItem out2 = new JMenuItem(output2 + " is the circumference");
    output.add(out1);
    output.add(out2);

     }

    public static void main(String[] arguments) {
        CircleFrame frame = new CircleFrame();
    }
}