Въведение в ООП с Java - Калкулатори

Пример - калкулатор:

//Calculateur
import java.awt.*;
import java.applet.*;
public class Calculateur extends Applet {
int arg1,arg2;
Button number[] = new Button[10];
Button func[] = new Button[4];
Panel num_panel;
Panel func_panel;
Panel rez_panel;
TextField rez;
int op_state; //0 - premier, 1 - deuxieme argument
char oper;
public void init(){
    op_state = arg1 = arg2 = 0;
    oper = ' ';
    setLayout(new BorderLayout());

    num_panel = new Panel();
    num_panel.setLayout(new GridLayout(4,3));
    for(int i=9; i>=0; i--){
    number[i] = new Button((new String()).valueOf(i));
    num_panel.add(number[i]);
    }
Calculateur :

    num_panel.add(new Button());
    func[1] = new Button("=");
    num_panel.add(func[1]);
    add("Center", num_panel);

    func_panel = new Panel();
    func_panel.setLayout(new GridLayout(4,1));
    func[2] = new Button("+");
    func_panel.add(func[2]);
    func[3] = new Button("-");
    func_panel.add(func[3]);
    func_panel.add(new Button());
    func_panel.add(new Button());

add("East",func_panel);

    rez_panel = new Panel();
    rez = new TextField("0",5);
    rez_panel.add(rez);
    add("North",rez_panel);

}
public boolean action(Event evt, Object arg) {
    for (int i = 0; i<=9; i++)
    if(evt.target.equals(number[i])){
      if (op_state != 0){ arg2 = i;rez.setText(arg2 + ""); }
      else {arg1 = i; rez.setText(arg1 + "");}
      return true;
    }

    for (int i = 1; i< 4; i++)
     if(evt.target.equals(func[i])) {
      switch (i) {
        case 1: if (oper == '+')
          rez.setText((arg1 + arg2)+ "");
          else if ( oper == '-')
          rez.setText((arg1-arg2) + "");
         op_state = 0; break;
        case 2: oper = '+'; op_state = 1; break;
        case 3: oper = '-'; op_state = 1;
      }
         return true;
     }
    return super.action(evt,arg);
}
}

Калкулатор с АWT 1.1

//CalculateurN
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
public class CalculateurN extends Applet {
    String arg1="";
    String arg2="";
    int rezVal;
Button number[] = new Button[10];
Button func[] = new Button[4];
Panel num_panel;
Panel func_panel;
Panel rez_panel;
TextField rez;
int op_state; //0 - premier, 1 - deuxieme argument
char oper;

public void init(){
op_state = 0;
oper = ' ';
setLayout(new BorderLayout());

num_panel = new Panel();
num_panel.setLayout(new GridLayout(4,3));
for(int i=9; i>=0; i--){
     number[i] = new Button((new String()).valueOf(i));
     number[i].addActionListener(new BN());
     num_panel.add(number[i]);
}
CalculateurN :

num_panel.add(new Button());
func[1] = new Button("=");
func[1].addActionListener(new BE());
num_panel.add(func[1]);
add("Center", num_panel);

func_panel = new Panel();
func_panel.setLayout(new GridLayout(4,1));
func[2] = new Button("+");
func[2].addActionListener(new BA());
func_panel.add(func[2]);

func[3] = new Button("-");
func[3].addActionListener(new BS());
func_panel.add(func[3]);
func_panel.add(new Button());
func_panel.add(new Button());

add("East",func_panel);

rez_panel = new Panel();
rez = new TextField("0",5);
rez_panel.add(rez);
add("North",rez_panel);

}

class BN implements ActionListener{
   public void actionPerformed(ActionEvent e) {
    if (op_state != 0){
    arg2 += e.getActionCommand();
    rez.setText(arg2);
    }
   else {
   arg1 += e.getActionCommand();
   rez.setText(arg1);
}
}
}

class BE implements ActionListener{
public void actionPerformed(ActionEvent e) {
if(oper == '+')
rezVal = (new Integer(arg1)).intValue() + (new Integer(arg2)).intValue();
else
rezVal = (new Integer(arg1)).intValue() - (new Integer(arg2)).intValue();
rez.setText(rezVal+"");
arg1= ""; arg2 = ""; op_state = 0;
}
}

class BA implements ActionListener{
public void actionPerformed(ActionEvent e) {
oper = '+';
op_state = 1;
}
}

class BS implements ActionListener{
public void actionPerformed(ActionEvent e) {
oper = '-';
op_state = 1;
}
}

// To close the application:
    static class WL extends WindowAdapter {
    public void windowClosing(WindowEvent e) {
      System.exit(0);
    }
    }

// A main() for the application:
    public static void main(String[] args) {
    CalculateurN applet = new CalculateurN();
    Frame aFrame = new Frame("CalculateurN");
    aFrame.addWindowListener(new WL());
    aFrame.add(applet, BorderLayout.CENTER);
    aFrame.setSize(300,200);
    applet.init();
    applet.start();
    aFrame.setVisible(true);
   }
}

Друг калкулатор

//CalcNC
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.applet.*;

public class CalcNC extends Applet {
   String arg="";
   int rezVal=0;
   Button number[] = new Button[10];
   Button func[] = new Button[6];
   Panel num_panel;
   Panel func_panel;
   Panel rez_panel;
   TextField rez,toper;
   char oper;
   public void init(){
       oper = ' ';
       setLayout(null);

       num_panel = new Panel();
       num_panel.setLayout(new GridLayout(4,3));
       for(int i=9; i>=0; i--){
           number[i] = new Button((new String()).valueOf(i));
           number[i].addActionListener(new BN());
           num_panel.add(number[i]);
       }

       func[0] = new Button("C");
       func[0].addActionListener(new C());
       num_panel.add(func[0]);

       func[1] = new Button("=");
       func[1].addActionListener(new OPER());
       num_panel.add(func[1]);
       num_panel.setBounds(20,100,180,180);
       add( num_panel);

       func_panel = new Panel();
       func_panel.setLayout(new GridLayout(4,1));
       func[2] = new Button("+");
       func[2].addActionListener(new OPER());
       func_panel.add(func[2]);

       func[3] = new Button("-");
       func[3].addActionListener(new OPER());
       func_panel.add(func[3]);

       func[4] = new Button("*");
       func[4].addActionListener(new OPER());
       func_panel.add(func[4]);

       func[5] = new Button("^");
       func[5].addActionListener(new OPER());
       func_panel.add(func[5]);

       func_panel.setBounds(210,100,65,180);
       add(func_panel);

       rez_panel = new Panel();
       rez = new TextField("0",10);
       toper = new TextField(" ",1);
       rez_panel.add(rez);
       rez_panel.add(toper);
       rez_panel.setBounds(20,20,240,40);
       add(rez_panel);

   }

   class BN implements ActionListener{
       public void actionPerformed(ActionEvent e) {
           arg += e.getActionCommand();
           rez.setText(arg);
           toper.setText("");
       }
   }

   class OPER implements ActionListener{
       public void actionPerformed(ActionEvent e) {
           int i,help,argi;
           if(arg.length()==0)argi=0;
           else argi = (new Integer(arg)).intValue();
           switch(oper){
           case '+': rezVal += argi;break;
           case '-': rezVal -= argi;break;
           case '*': rezVal *= argi;break;
           case '=': oper = ' ';break;
           case '^': for(i=1,help=rezVal; i < argi;i++)
               rezVal *=help;
           break;
           case ' ': rezVal= argi;
           }
           rez.setText(rezVal+"");
           arg = "";
           oper = e.getActionCommand().charAt(0);
           if(oper!='=')toper.setText(oper+"");
           else toper.setText("");
       }
   }
   class C implements ActionListener{
       public void actionPerformed(ActionEvent e) {
           arg = "";
           rezVal =0;
           oper = ' ';
           rez.setText(rezVal+"");
           toper.setText("");
       }
   }

   // A main() for the application:
   public static void main(String[] args) {
       CalcNC applet = new CalcNC();
       JFrame aFrame = new JFrame("CalcNC");
       aFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
       aFrame.add(applet, BorderLayout.CENTER);
       aFrame.setSize(400,400);
       applet.init();
       applet.start();
       aFrame.setVisible(true);
   }
} CalcNC :