Miscellany

import java.awt.*;import javax.swing.*;class MiniCalc extends JFrame{    public static void main(String[] args)    {        MiniCalc program = new MiniCalc();        program.run();    }    public void run()    {        setTitle("MiniCalc");                setDefaultCloseOperation(EXIT_ON_CLOSE);        Container pane = new Container();        Box screen = new Box(BoxLayout.Y_AXIS);        Box box = new Box(BoxLayout.X_AXIS);        JTextField newnumber = new JTextField(20);                JTextField currentnumber = new JTextField(20);        DoMath listener = new DoMath(currentnumber,newnumber);                        AddString listener2 = new AddString(newnumber);        box.add(new JLabel("Result"));        box.add(currentnumber);                currentnumber.setText("0");        box.add(new JLabel("NewNumber"));        box.add(newnumber);        pane.setLayout(new GridLayout(4,4));        JButton b11 = button2("7", listener2, pane);        JButton b12 = button2("8", listener2, pane);        JButton b13 = button2("9", listener2, pane);                        JButton b1 = button("Add", listener, pane);                 JButton b8 = button2("4", listener2, pane);        JButton b9 = button2("5", listener2, pane);        JButton b10 = button2("6", listener2, pane);        JButton b2 = button("Subtract", listener, pane);        JButton b5 = button2("1", listener2, pane);        JButton b6 = button2("2", listener2, pane);        JButton b7 = button2("3", listener2, pane);        JButton b3 = button("Multiply", listener, pane);        JButton b14 = button2("0", listener2, pane);        JButton b15 = button2(".", listener2, pane);        JButton b16 = button("=", listener, pane);        JButton b4 = button("Divide", listener, pane);        screen.add(box);        screen.add(pane);        add(screen);                pack();        setVisible(true);    }    JButton button(String text, DoMath listener,Container pane)    {        JButton b = new JButton(text);        b.addActionListener(listener);        pane.add(b);        return b;    }    JButton button2(String text, AddString listener, Container pane)    {        JButton b = new JButton(text);        b.addActionListener(listener);        pane.add(b);        return b;    }}