계산기 만들었습니다.

awt로 된 완전 초보 계산기입니다..
웹개발만 하다보니 기초자바가 재미있네영..^^;;

import java.awt.*;
import java.awt.event.*;

public class CalcCreateExam extends Frame
{
 Frame f;
 Panel pl_0,pl_1;
 MenuBar mb;
 Menu m1,m2,m3;
 MenuItem menu_exit;
 Button b1,b2,b3,b4,b5,b6,b7,b8,b9,b0;
 Button bs,ce,bc;
 Button bmc,bmr,bms,bmplus;
 Button bslush,bsq,bminus,bplus;
 Button bresult;
 TextField result_tf;
 // button_al;
 int result_number = 0;
 char ch,privous_ch;
 String str_Result = "";
 String privous_number = "";
 String non_check_number = "";
 String final_result_number = "";

 public CalcCreateExam()
 {
  
  f= new Frame("자바계산기");
  //main = new Panel(new GridLayout());

  pl_0 = new Panel(new GridLayout());
  mb = new MenuBar();
  f.setMenuBar(mb);
  m1=new Menu("편집");
  m2=new Menu("보기");
  m3=new Menu("도움말");

  menu_exit = new MenuItem("나가기");

  mb.add(m1);
  mb.add(m2);
  mb.add(m3);

  m1.add(menu_exit);

  result_tf = new TextField();
  //result_tf.setAlignment();
  //System.out.println();
  
  pl_0.add(result_tf);

  pl_1 = new Panel(new GridLayout(4,4));
  //f = new Frame();
  //result_tf = new TextField(10);
  b1 = new Button("1");
  b2 = new Button("2");
  b3 = new Button("3");
  b4 = new Button("4");
  b5 = new Button("5");
  b6 = new Button("6");
  b7 = new Button("7");
  b8 = new Button("8");
  b9 = new Button("9");
  b0 = new Button("0");
  bc = new Button("C");
  
  bplus = new Button("+");
  bminus = new Button("-");
  bslush = new Button("/");
  bsq = new Button("*");
  //bplus = new Button("+");
  //bplus = new Button("+");
  bresult = new Button("=");//결과버튼
    
  pl_1.add(b9);
  pl_1.add(b8);
  pl_1.add(b7);
  pl_1.add(b6);
  pl_1.add(b5);
  pl_1.add(b4);
  pl_1.add(b3);
  pl_1.add(b2);
  pl_1.add(b1);
  pl_1.add(b0);
  pl_1.add(bplus);
  pl_1.add(bminus);
  pl_1.add(bslush);
  pl_1.add(bsq);
  pl_1.add(bc);
  pl_1.add(bresult);
  
  //pl.setLayout(new GridLayout());
  f.add(pl_1,BorderLayout.CENTER);
  f.add(pl_0,BorderLayout.NORTH);

  //f.add(main);
  
  //이벤트 구현

  ActionListener button_al = new ActionListener()
  {
   public void actionPerformed(ActionEvent ae)
   {
    //System.out.println(ae.getSource().getText());   
    
    
    non_check_number = (String)ae.getActionCommand();

    if(non_check_number.length()==1)
    {
     ch = non_check_number.charAt(0);
     if(Character.isDigit(ch))//숫자인지판단
     {
      str_Result += non_check_number;
      final_result_number = str_Result;
      //System.out.println("!!!!!!!!!!! ++++ : "+str_Result);
     }
     else
     {
      
      switch(ch)
      {       
       case '=':
        Caculate(privous_ch);
        break;
       case 'C':
        privous_number = "";
        str_Result = "";
        //privous_math=new char('');
        non_check_number = "";
        //System.out.println("c");
        break;       
       default :
        privous_ch=ch;
        break;
      }
     
     privous_number = str_Result;
     final_result_number = non_check_number;
     str_Result = "";//초기화
     }    
    }
    
       
   
   //System.out.println("결과창 : " + non_check_number);
   result_tf.setText(final_result_number);
   }

  };//ActionListener
  
  b1.addActionListener(button_al);
  b2.addActionListener(button_al);
  b3.addActionListener(button_al);
  b4.addActionListener(button_al);
  b5.addActionListener(button_al);
  b6.addActionListener(button_al);
  b7.addActionListener(button_al);
  b8.addActionListener(button_al);
  b9.addActionListener(button_al);
  b0.addActionListener(button_al);  
  bresult.addActionListener(button_al);
  bplus.addActionListener(button_al);
  bminus.addActionListener(button_al);
  bslush.addActionListener(button_al);
  bsq.addActionListener(button_al);
  bc.addActionListener(button_al);  
  menu_exit.addActionListener(new ActionListener()
  {
   public void actionPerformed(ActionEvent ae)
   {
    System.exit(0);
   }
  });
 }
 public void Caculate(Character ch1)
 {
  //System.out.println("111111111,"+privous_number+","+str_Result);
  int number1 = Integer.parseInt(privous_number);
  int number2 = Integer.parseInt(str_Result);
  //System.out.println("22222222,"+number1+":"+number2);

  switch(ch1)
  {
   case '+' :
    number1+=number2;
    //System.out.println("result : "+number1);
    break;
   case '-' :
    number1-=number2;
    break;
   case '*' :
    number1*=number2;
    break;
   case '/' :
    number1/=number2;
    break;
   
   //default :
    //System.out.println(result_tf.getText());
  }
  //텍스트창에서 안나옴..==;
  non_check_number = Integer.toString(number1);
  
  //System.out.println(number1+math+number2);
 }
 public void CreateFrame()
 {
  
  f.addWindowListener(new WindowAdapter() 
        {
          public void windowClosing(WindowEvent e) 
          {
              System.exit(0);
              
           }
         });

  f.setSize(300,250);
  f.setVisible(true);
  
 }
 public static void main(String[] args)
 {
  CalcCreateExam cce = new CalcCreateExam();
  cce.CreateFrame();
 }
}

완전 허접하다...하지만 조금 더 좋아질 것 같다..ㅋㅋ