简易计算器的制作

package yan01;
    import java.awt.BorderLayout;
    import java.awt.GridLayout;
    import java.awt.event.ActionEvent;
    import java.awt.event.ActionListener;
    import java.util.StringTokenizer;
     
    import javax.swing.JButton;
    import javax.swing.JFrame;
    import javax.swing.JPanel;
    import javax.swing.JTextField;
     
    public class Calculator extends JFrame{
        JPanel panel;
        JTextField text;
        JButton jb0,jb1,jb2,jb3,jb4,jb5,jb6,jb7,jb8,jb9;    //0~9四个数字（可写成数组）
        JButton bot,add,sub,mul,div,equ;    //加减乘除以及小数点五个符号
        public Calculator(){
            this.setBounds(300, 200, 400, 300);    //窗体大小
            this.setTitle("计算器");    //窗体名称
            this.setLayout(new BorderLayout());    //设置计算机窗体的布局方式
            
            text = new JTextField(15);        //计算区域
            
            //新建数字按钮
            jb0 = new JButton("0");
            jb1 = new JButton("1");
            jb2 = new JButton("2");
            jb3 = new JButton("3");
            jb4 = new JButton("4");
            jb5 = new JButton("5");
            jb6 = new JButton("6");
            jb7 = new JButton("7");
            jb8 = new JButton("8");
            jb9 = new JButton("9");
            
            //新建符号按钮
            bot = new JButton(".");
            add = new JButton("+");
            sub = new JButton("-");
            mul = new JButton("*");
            div = new JButton("/");
            equ = new JButton("=");
            
            //新建计算器数字及符号所在区域面板
            panel = new JPanel();
            panel.setLayout(new GridLayout(4,4));    //设置面板的布局方式
            
            //将各按钮组件放入面板（panel）中
            //第一行
            panel.add(jb7);
            panel.add(jb8);
            panel.add(jb9);
            panel.add(div);
            //第二行
            panel.add(jb4);
            panel.add(jb5);
            panel.add(jb6);
            panel.add(mul);
            //第三行
            panel.add(jb1);
            panel.add(jb2);
            panel.add(jb3);
            panel.add(sub);
            //第四行
            panel.add(bot);
            panel.add(jb0);
            panel.add(equ);
            panel.add(add);
            
            
            this.add(text,BorderLayout.NORTH);
            this.add(panel);
            
            MyEvent();    //事件处理
            
            this.setVisible(true);    //设置窗体显示
            this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);    //设置窗体可关闭
        }
        
        public void MyEvent(){
            /*将以下内容封装到Text方法中
             * jb0.addActionListener(new ActionListener(){
                @Override
                public void actionPerformed(ActionEvent arg0) {
                    // TODO Auto-generated method stub
//                    text.setText("0");
                    String str = jb0.getText();
                    System.out.println(str);
                }
                
            });*/
            //为各按钮添加事件处理
            Text(jb0);
            Text(jb1);
            Text(jb2);
            Text(jb3);
            Text(jb4);
            Text(jb5);
            Text(jb6);
            Text(jb7);
            Text(jb8);
            Text(jb9);
            Text(bot);
            Text(add);
            Text(sub);
            Text(mul);
            Text(div);
            
            //“=”按钮的事件处理
            equ.addActionListener(new ActionListener(){
     
                @Override
                public void actionPerformed(ActionEvent e) {
                    // TODO Auto-generated method stub
                    
                    text.setText(text.getText()+equ.getText());
                    
                    if(text.getText().contains("+")){//做加法运算
//                        String[] str1 = text.getText().split("+");        //错误语句
                        StringTokenizer st1 = new StringTokenizer(text.getText(),"+");
//                        System.out.println("str1======"+st1.nextToken());
                        double d1,d2 = 0;
                        d1 = Double.parseDouble(st1.nextToken());
                        while(st1.hasMoreTokens()){
                            StringTokenizer st2 = new StringTokenizer(st1.nextToken(),"=");
//                            System.out.println("str2======"+st2.nextToken());
                            d2 = Double.parseDouble(st2.nextToken());
                        }
                        
                        text.setText(text.getText()+" "+(d1+d2));
                    }else if(text.getText().contains("-")){//做减法运算
                        StringTokenizer st1 = new StringTokenizer(text.getText(),"-");
                        double d1,d2 = 0;
                        d1 = Double.parseDouble(st1.nextToken());
                        while(st1.hasMoreTokens()){
                            StringTokenizer st2 = new StringTokenizer(st1.nextToken(),"=");
                            d2 = Double.parseDouble(st2.nextToken());
                        }
                        
                        text.setText(text.getText()+" "+(d1-d2));
                    }else if(text.getText().contains("*")){//做乘法运算
                        StringTokenizer st1 = new StringTokenizer(text.getText(),"*");
                        double d1,d2 = 0;
                        d1 = Double.parseDouble(st1.nextToken());
                        while(st1.hasMoreTokens()){
                            StringTokenizer st2 = new StringTokenizer(st1.nextToken(),"=");
                            d2 = Double.parseDouble(st2.nextToken());
                        }
                        
                        text.setText(text.getText()+" "+(d1*d2));
                    }else if(text.getText().contains("/")){//做除法运算
                        StringTokenizer st1 = new StringTokenizer(text.getText(),"/");
                        double d1,d2 = 0;
                        d1 = Double.parseDouble(st1.nextToken());
                        while(st1.hasMoreTokens()){
                            StringTokenizer st2 = new StringTokenizer(st1.nextToken(),"=");
                            d2 = Double.parseDouble(st2.nextToken());
                        }
                        
                        text.setText(text.getText()+" "+(d1/d2));    //将运算结果放到text区域
                    }
                }
                
            });
        }
        
        //各按钮的事件处理方法
        public void Text(JButton button){
            button.addActionListener(new ActionListener(){
     
                @Override
                public void actionPerformed(ActionEvent arg0) {
                    // TODO Auto-generated method stub
//                    text.setText("0");
                    String str = button.getText();
//                    System.out.println(str);
                    text.setText(text.getText()+str);
                }
                
            });
//            return button.getText();
        }
        
        //主函数
        public static void main(String[] args) {
            // TODO Auto-generated method stub
            new Calculator();
        }
    }

实现效果：