计算器JAVA源代码

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;

 class Jsqzj implements ActionListener
{    
    JButton b1,b2,b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13,b14,b15,b16;
    JFrame f;
    GridLayout c=new GridLayout(4,4);
    JTextField tf = new JTextField();
    public void init()
    {
      f=new JFrame("CardLayout testing");
     Container ct = f.getContentPane();
     tf.setHorizontalAlignment(JTextField.RIGHT);
     ct.add(tf,"North");
     JPanel p2=new JPanel();  
     ct.add(p2,"Center");
     GridLayout c=new GridLayout(4,4);            
      p2.setLayout(c);                      

      JButton b1,b2,b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13,b14,b15,b16;
        b1=new JButton("1");
        b2=new JButton("2");
        b3=new JButton("3");
        b4=new JButton("4");
        b5=new JButton("5");
        b6=new JButton("6");
        b7=new JButton("7");
        b8=new JButton("8");
        b9=new JButton("9");
        b10=new JButton("0");        
        b11=new JButton(".");
        b12=new JButton("=");
        b13=new JButton("+");
        b14=new JButton("-");
        b15=new JButton("x");
        b16=new JButton("/");               

        p2.add(b1);
        b1.addActionListener(this);
        p2.add(b2);
        b2.addActionListener(this);
        p2.add(b3);
        b3.addActionListener(this);
        p2.add(b13);
        b13.addActionListener(this);
        p2.add(b4);
        b4.addActionListener(this);
        p2.add(b5);
        b5.addActionListener(this);
        p2.add(b6);
        b6.addActionListener(this);
        p2.add(b14);
        b14.addActionListener(this);
        p2.add(b7);
        b7.addActionListener(this);
        p2.add(b8);
        b8.addActionListener(this);
        p2.add(b9);
        b9.addActionListener(this);
        p2.add(b15);
        b15.addActionListener(this);
        p2.add(b10);
        b10.addActionListener(this);
        p2.add(b11);
        b11.addActionListener(this);
        p2.add(b12);
        b12.addActionListener(this);       
        p2.add(b16);
        b16.addActionListener(this);        

        f.addWindowListener(new WindowAdapter()
                          {
                           public void windowClosing(WindowEvent e)
                           {
                            System.exit(0);
                           }
                          });
        f.setSize(200,180);
        f.setVisible(true);
    }
    double sum=0;
    Vector v=new Vector(1,1);
    Vector v2=new Vector(1,1);
    public Jsqzj()
    {
     v2.addElement(new String("init"));
      v.addElement(new String("init"));
    }
    public void actionPerformed(ActionEvent e)
   {    
    String str=tf.getText();         
     if(e.getActionCommand()=="+")      //加号的实现；
     {       
       if(
            ("+").equals((String)v2.lastElement()) ||
             ("-").equals((String)v2.lastElement()) ||
             ("x").equals((String)v2.lastElement()) ||
             ("/").equals((String)v2.lastElement()) ||
             ("=").equals((String)v2.lastElement())
          )
        {
         tf.setText(String.valueOf(sum));
        }
        else if(("init").equals((String)v2.lastElement()))
             {
               tf.setText(String.valueOf(sum));
               v2.addElement(new String("="));
             }
          else
           {
              double d=Double.parseDouble(str);
             if (("+").equals((String)v.lastElement()))
             {                    
              sum=sum+d;
               tf.setText(String.valueOf(sum));
              }
              else if (("-").equals((String)v.lastElement()))
                   {
                      sum=sum-d;
                     tf.setText(String.valueOf(sum));
                   }
                   else if(("x").equals((String)v.lastElement()))
                        {
                          sum=sum*d;
                          tf.setText(String.valueOf(sum));
                        }
                        else if(("/").equals((String)v.lastElement()))
                             {
                                  sum=sum/d;
                                 tf.setText(String.valueOf(sum));
                             }
                             else if(("=").equals((String)v.lastElement()))
                                  {  
                                    sum=sum+d;                               
                                    tf.setText(String.valueOf(sum));
                                  }
                                  else
                                  {
                                    sum=sum+d;
                                    tf.setText(String.valueOf(sum));
                                  }           
              }
        v.addElement(new String("+"));
        v2.addElement(new String("+"));              
     }

     if(e.getActionCommand()=="-")                      //减号的实现；
     {       
       if(
            ("+").equals((String)v2.lastElement()) ||
             ("-").equals((String)v2.lastElement()) ||
             ("x").equals((String)v2.lastElement()) ||
             ("/").equals((String)v2.lastElement()) ||
             ("=").equals((String)v2.lastElement())
          )
        {
         tf.setText(String.valueOf(sum));
        }
        else if(("init").equals((String)v2.lastElement()))
             {
               tf.setText(String.valueOf(sum));
               v2.addElement(new String("="));
             }
          else
           {
              double d=Double.parseDouble(str);
             if (("+").equals((String)v.lastElement()))
             {                    
              sum=sum+d;
               tf.setText(String.valueOf(sum));
              }
              else if (("-").equals((String)v.lastElement()))
                   {
                      sum=sum-d;
                     tf.setText(String.valueOf(sum));
                   }
                   else if(("x").equals((String)v.lastElement()))
                        {
                          sum=sum*d;
                          tf.setText(String.valueOf(sum));
                        }
                        else if(("/").equals((String)v.lastElement()))
                             {
                                  sum=sum/d;
                                 tf.setText(String.valueOf(sum));
                             }
                             else if(("=").equals((String)v.lastElement()))
                                  {  
                                    sum=sum+d;                               
                                    tf.setText(String.valueOf(sum));
                                  }
                                  else
                                  {
                                    sum=sum+d;
                                    tf.setText(String.valueOf(sum));
                                  }           
              }
        v.addElement(new String("-"));
        v2.addElement(new String("-"));              
     }

     if(e.getActionCommand()=="x")      //乘号的实现；
     {       
       if(
            ("+").equals((String)v2.lastElement()) ||
             ("-").equals((String)v2.lastElement()) ||
             ("x").equals((String)v2.lastElement()) ||
             ("/").equals((String)v2.lastElement()) ||
             ("=").equals((String)v2.lastElement())
          )
        {
         tf.setText(String.valueOf(sum));
        }
        else if(("init").equals((String)v2.lastElement()))
             {
               tf.setText(String.valueOf(sum));
               v2.addElement(new String("="));
             }
          else
           {
              double d=Double.parseDouble(str);
             if (("+").equals((String)v.lastElement()))
             {                    
              sum=sum+d;
               tf.setText(String.valueOf(sum));
              }
              else if (("-").equals((String)v.lastElement()))
                   {
                      sum=sum-d;
                     tf.setText(String.valueOf(sum));
                   }
                   else if(("x").equals((String)v.lastElement()))
                        {
                          sum=sum*d;
                          tf.setText(String.valueOf(sum));
                        }
                        else if(("/").equals((String)v.lastElement()))
                             {
                                  sum=sum/d;
                                 tf.setText(String.valueOf(sum));
                             }
                             else if(("=").equals((String)v.lastElement()))
                                  {  
                                    sum=sum+d;                               
                                    tf.setText(String.valueOf(sum));
                                  }
                                  else
                                  {
                                    sum=sum+d;
                                    tf.setText(String.valueOf(sum));
                                  }           
              }
        v.addElement(new String("x"));
        v2.addElement(new String("x"));              
     }

     if(e.getActionCommand()=="/")      //除号的实现；
     {       
       if(
            ("+").equals((String)v2.lastElement()) ||
             ("-").equals((String)v2.lastElement()) ||
             ("x").equals((String)v2.lastElement()) ||
             ("/").equals((String)v2.lastElement()) ||
             ("=").equals((String)v2.lastElement())
          )
        {
         tf.setText(String.valueOf(sum));
        }
        else if(("init").equals((String)v2.lastElement()))
             {
               tf.setText(String.valueOf(sum));
               v2.addElement(new String("="));
             }
          else
           {
              double d=Double.parseDouble(str);
             if (("+").equals((String)v.lastElement()))
             {                    
              sum=sum+d;
               tf.setText(String.valueOf(sum));
              }
              else if (("-").equals((String)v.lastElement()))
                   {
                      sum=sum-d;
                     tf.setText(String.valueOf(sum));
                   }
                   else if(("x").equals((String)v.lastElement()))
                        {
                          sum=sum*d;
                          tf.setText(String.valueOf(sum));
                        }
                        else if(("/").equals((String)v.lastElement()))
                             {
                                  sum=sum/d;
                                 tf.setText(String.valueOf(sum));
                             }
                             else if(("=").equals((String)v.lastElement()))
                                  {  
                                    sum=sum+d;                               
                                    tf.setText(String.valueOf(sum));
                                  }
                                  else
                                  {
                                    sum=sum+d;
                                    tf.setText(String.valueOf(sum));
                                  }           
              }
        v.addElement(new String("/"));
        v2.addElement(new String("/"));              
     }

     if (e.getActionCommand()=="=" )    //等号实现；    
     {   
        if(
            ("+").equals((String)v2.lastElement()) ||
             ("-").equals((String)v2.lastElement()) ||
             ("x").equals((String)v2.lastElement()) ||
             ("/").equals((String)v2.lastElement()) ||
             ("=").equals((String)v2.lastElement())
          )
        {
         tf.setText(String.valueOf(sum));
        }
        else if(("init").equals((String)v2.lastElement()))
             {tf.setText(String.valueOf(sum));}
          else
           {
              double d=Double.parseDouble(str);
             if (("+").equals((String)v.lastElement()))
             {                   
              sum=sum+d;
               tf.setText(String.valueOf(sum));
              }
              else if (("-").equals((String)v.lastElement()))
                   {
                      sum=sum-d;
                     tf.setText(String.valueOf(sum));
                   }
                   else if(("x").equals((String)v.lastElement()))
                        {
                          sum=sum*d;
                          tf.setText(String.valueOf(sum));
                        }
                        else if(("/").equals((String)v.lastElement()))
                             {
                                  sum=sum/d;
                                 tf.setText(String.valueOf(sum));
                             }
                             else if(("=").equals((String)v.lastElement()))
                                  {  
                                     sum=sum+d;
                                    tf.setText(String.valueOf(sum));                              
                                    //tf.setText(String.valueOf(sum));
                                  }
                                  else
                                  {
                                    sum=sum+d;
                                    tf.setText(String.valueOf(sum));
                                  }
            }
        v.addElement(new String("="));
        v2.addElement(new String("="));              
       }

      if (e.getActionCommand()=="1" ||                       
          e.getActionCommand()=="2" ||
          e.getActionCommand()=="3" ||
          e.getActionCommand()=="4" ||
          e.getActionCommand()=="5" ||
          e.getActionCommand()=="6" ||
          e.getActionCommand()=="7" ||
          e.getActionCommand()=="8" ||
          e.getActionCommand()=="9" ||
          e.getActionCommand()=="0" ||
          e.getActionCommand()=="."           
         )                              //1，2，3，4，5，6，7，8，9，0，.的实现；
    {     
      if(
            ("+").equals((String)v2.lastElement()) ||
             ("-").equals((String)v2.lastElement()) ||
             ("x").equals((String)v2.lastElement()) ||
             ("/").equals((String)v2.lastElement()) ||
             ("init").equals((String)v2.lastElement())             
        )
        {          
          tf.setText("");
          tf.setText(e.getActionCommand());
        }
      else if (("=").equals((String)v2.lastElement()))
           {
            sum=0;
            tf.setText("");
             tf.setText(e.getActionCommand());
           }
        else
         {
             tf.setText(tf.getText()+e.getActionCommand());//调用其父类中的getText()方法
          }
          v2.addElement(new String(e.getActionCommand()));
    }


    }
    public static void main(String args[])
    {
       new Jsqzj().init();        
    }

}