Ajuda!

import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseEvent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.JButton;

public class Calcl extends JFrame
{
	private JPanel p1,p2;
	private JTextField visor;
	private JButton  um,dois,tres,quatro,cinco,seis,sete,oito,nove,zero,ponto,igual,mais,menos,divisao,multi;
	private String aux = "";
	private String aux2 = "";
	private Double op1;
	private Double op2;
	private int operacao;
	private boolean sinal;
	private Double total;

	public Calcl()
	{
		super("Calculadora JAVA");
		setLayout(new BorderLayout());


		p1 = new JPanel();



		p1.setLayout(new FlowLayout(FlowLayout.CENTER));
		visor = new JTextField(20);
		visor.setHorizontalAlignment(JTextField.RIGHT);
		p1.add(visor);

		p2= new JPanel();
		p2.setLayout(new GridLayout(4,4,1,1));

		sete = new JButton("7");
		p2.add(sete);

		oito = new JButton("8");
		p2.add(oito);

		nove = new JButton("9");
		p2.add(nove);

		divisao = new JButton("/");
		p2.add(divisao);

		quatro = new JButton("4");
		p2.add(quatro);

		cinco = new JButton("5");
		p2.add(cinco);

		seis = new JButton("6");
		p2.add(seis);

		multi = new JButton("*");
		p2.add(multi);

		um = new JButton("1");
		p2.add(um);

		dois = new JButton("2");
		p2.add(dois);

		tres = new JButton("3");
		p2.add(tres);

		menos = new JButton("-");
		p2.add(menos);

		zero = new JButton("0");
		p2.add(zero);

		ponto = new JButton(".");
		p2.add(ponto);

		igual = new JButton("=");
		p2.add(igual);

		mais = new JButton("+");
		p2.add(mais);


		add(BorderLayout.NORTH,p1);
		add(BorderLayout.SOUTH,p2);

		TecladoNum trat = new TecladoNum();

		sete.addActionListener(trat);
		oito.addActionListener(trat);
		nove.addActionListener(trat);
		quatro.addActionListener(trat);
		cinco.addActionListener(trat);
		seis.addActionListener(trat);
		um.addActionListener(trat);
		dois.addActionListener(trat);
		tres.addActionListener(trat);
		zero.addActionListener(trat);



	TecladoNum2 trat2 = new TecladoNum2();

	divisao.addActionListener(trat2);
	multi.addActionListener(trat2);
	menos.addActionListener(trat2);
	mais.addActionListener(trat2);
	igual.addActionListener(trat2);
}




		private class TecladoNum implements ActionListener
		{
			public void actionPerformed (ActionEvent e)
			{

					if(e.getActionCommand().equals("7"))
					{
						aux+= e.getActionCommand();
					}

				else{

					if(e.getActionCommand().equals("8"))
					{
						aux+= e.getActionCommand();
					}

				else

						if(e.getActionCommand().equals("9"))
					{
						aux+= e.getActionCommand();
					}

				else


					if(e.getActionCommand().equals("4"))
					{
						aux+= e.getActionCommand();
					}

				else


					if(e.getActionCommand().equals("5"))
					{
						aux+= e.getActionCommand();
					}

				else


					if(e.getActionCommand().equals("6"))
					{
						aux+= e.getActionCommand();
					}

				else


					if(e.getActionCommand().equals("1"))
					{
						aux+= e.getActionCommand();
					}

				else


					if(e.getActionCommand().equals("2"))
					{
						aux+= e.getActionCommand();
					}


				else


					if(e.getActionCommand().equals("3"))
					{
						aux+= e.getActionCommand();
					}


				else



					if(e.getActionCommand().equals("0"))
					{
						aux+= e.getActionCommand();
					}

					if(e.getActionCommand().equals("."))
					{
						aux+= e.getActionCommand();
					}

					visor.setText(aux);



			}
		}
	}

		private class TecladoNum2 implements ActionListener
		{

			public void actionPerformed (ActionEvent e)

				{

					if(e.getActionCommand().equals("/"))
					{
						op1=Double.parseDouble(visor.getText());
						operacao = 1;
						sinal = false;
					}


				else{

					if(e.getActionCommand().equals("*"))
					{
						op1=Double.parseDouble(visor.getText());
						operacao = 2;
						sinal = false;
					}

					else

					if(e.getActionCommand().equals("+"))
				    {
						op1=Double.parseDouble(visor.getText());
						operacao = 3;
						sinal = false;
                    }

					else

					if(e.getActionCommand().equals("-"))
					{
						op1=Double.parseDouble(visor.getText());
						operacao = 4;
						sinal = false;
					}

					else

					if (e.getActionCommand().equals("="));
					{

					switch (operacao)
						{
					   case 1 : total = op1/op2;
					   case 2 : total = op1*op2;
					   case 3 : total = op1+op2;
					   case 4 : total = op1-op2;
					   visor.setText(String.valueOF(total));
					   }
					}

					}
					}
					}



         public static void main(String args[])
		{
			JFrame app = new Calcl();
			app.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
			app.pack();
			app.setVisible(true);
		}
}