아직은 인터페이스만...;;
~cpp 
import java.awt.*;
import javax.swing.*;
public class MyCalculator extends JFrame {
	JButton numberButton[];
	JTextField inputField = new JTextField();
	public MyCalculator() {
		GridBagLayout gridbag = new GridBagLayout();
		GridBagConstraints c = new GridBagConstraints();
		
		this.setTitle("Calculator");
		getContentPane().setLayout(gridbag);
		c.fill = GridBagConstraints.BOTH;
		c.weightx = 1.0;
		c.weighty = 1.0;
		c.gridwidth = GridBagConstraints.REMAINDER; //end row
		gridbag.setConstraints(inputField, c);
		getContentPane().add(inputField);
		c.weightx = 1.0;
		c.gridwidth = GridBagConstraints.LAST_LINE_END;
		
		makebutton("+", gridbag, c);
		makebutton("-", gridbag, c);
		makebutton("*", gridbag, c);
		c.gridwidth = GridBagConstraints.REMAINDER; //end row
		makebutton("/", gridbag, c);
		c.gridwidth = GridBagConstraints.LAST_LINE_END;
		makebutton("1", gridbag, c);
		makebutton("2", gridbag, c);
		makebutton("3", gridbag, c);
		c.gridwidth = GridBagConstraints.REMAINDER; //end row
		makebutton("<-", gridbag, c);
		c.gridwidth = GridBagConstraints.LAST_LINE_END;
		makebutton("4", gridbag, c);
		makebutton("5", gridbag, c);
		makebutton("6", gridbag, c);
		c.gridwidth = GridBagConstraints.REMAINDER; //end row
		makebutton("C", gridbag, c);
		c.gridwidth = GridBagConstraints.LAST_LINE_END;
		makebutton("7", gridbag, c);
		makebutton("8", gridbag, c);
		makebutton("9", gridbag, c);
		c.gridwidth = GridBagConstraints.REMAINDER; //end row
		makebutton("=", gridbag, c);
		setSize(300, 200);
		setVisible(true);
	}
	private void makebutton(
		String name,
		GridBagLayout gridbag,
		GridBagConstraints c) {
		Button button = new Button(name);
		gridbag.setConstraints(button, c);
		getContentPane().add(button);
	}
	public static void main(String[] args) {
		MyCalculator calculator = new MyCalculator();
	}
}













