java计算器求解功能跑步起来求解！！！！！

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class work implements ActionListener {

public int num1,num2,nun3;
public  int add,sub,div,mul;
public String str=null;
public int end;
public static void main(String[] args){

work homewok=new work();

}
public work()
{
   JFrame jf1=null;
   JPanel jp1=null,jp2=null;
   JButton jb0=null,jb1=null,jb2=null,jb3=null,jb4=null,jb5=null,jb6=null,jb7=null,jb8=null,jb9=null,b1=null,b2=null,b3=null,b4=null,c1=null;;
   JLabel jl1=null;
   JTextField jt1=null;
   jf1=new JFrame();

   jp1=new JPanel(new FlowLayout());
   jp2=new JPanel(new GridLayout(3,5));
   jb0=new JButton("0");
   jb0.addActionListener(this);
   jb1=new JButton("1");
   jb1.addActionListener(this);
   jb2=new JButton("2");
   jb2.addActionListener(this);
   jb3=new JButton("3");
   jb3.addActionListener(this);
   jb4=new JButton("4");
   jb4.addActionListener(this);
   jb5=new JButton("5");
   jb5.addActionListener(this);
   jb6=new JButton("6");
   jb6.addActionListener(this);
   jb7=new JButton("7");
   jb7.addActionListener(this);
   jb8=new JButton("8");
   jb8.addActionListener(this);
   jb9=new JButton("9");
   jb9.addActionListener(this);
   b1=new JButton("+");
   b1.addActionListener(this);
   b2=new JButton("-");
   b2.addActionListener(this);
   b3=new JButton("*");
   b3.addActionListener(this);
   b4=new JButton("/");
   b4.addActionListener(this);
   c1=new JButton("=");
   c1.addActionListener(this);
   jl1=new JLabel("请输入数");
   jt1=new JTextField(8);

   jf1.add(jp1,BorderLayout.NORTH);
   jf1.add(jp2,BorderLayout.SOUTH);

   jp1.add(jl1);
   jp1.add(jt1);

   jp2.add(jb0);
   jp2.add(jb1);
   jp2.add(jb2);
   jp2.add(jb3);
   jp2.add(jb4);
   jp2.add(jb5);
   jp2.add(jb6);
   jp2.add(jb7);
   jp2.add(jb8);
   jp2.add(jb9);
   jp2.add(b1);
   jp2.add(b2);
   jp2.add(b3);
   jp2.add(b4);
   jp2.add(c1);

   jf1.setSize(400, 400);
   jf1.setTitle("my work 计算器");
   jf1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   jf1.setVisible(true);


}
public void num(int i)
{
String s=null;
s=String.valueOf(i);
if(end==1)
{
jt1.setText(0);
    end=0;
    }
if((jt1.getText()).equals("0"))
{
str=jt1.getText()+s;
jt1.setText(str);

}
}

public void actionPerformed( ActionEvent e)

{
   if(e.getSource()==jb0)
   num(0);
   else if(e.getSource()==jb1)
       num(1);
   else if(e.getSource()==jb2)
       num(2);
   else if(e.getSource()==jb3)
       num(3);
   else if(e.getSource()==jb4)
       num(4);
   else if(e.getSource()==jb5)
       num(5);

   else if(e.getSource()==jb6)
       num(6);
   else if(e.getSource()==jb7)
       num(7);
   else if(e.getSource()==jb8)
       num(8);
   else if(e.getSource()==jb9)
       num(9);
   else if(e.getSource()==b1)
       sign(1);
   else if(e.getSource()==b2)
       sign(2);
   else if(e.getSource()==b3)
       sign(3);
   else if(e.getSource()==b4)
       sign(4);
   else if(e.getSource()==c1)
   {
num2=Integer.parseInt(jt1.getText());

   if(add==1)
   num1=num1+num2;
   else if(sub==1)
   num1=num1+num2;
   else if(div==1)
   num1=num1/num2;
   else if(mul==1)
   num1=num1*num2;
jt1.setText(num1);
}
jt1.setText(String.valueOf(num1));
end=1;
}
public void sign(int i)
{
if(i==1)
{
add=1;
sub=0;
div=0;
mul=0;
}
if(i==2)
{
add=0;
sub=1;
div=0;
mul=0;
}
if(i==3)
{
add=0;
sub=0;
div=0;
mul=0;
}

if(i==4)
{
add=0;
sub=0;
div=1;
mul=0;
}

}

}
--------------------编程问答-------------------- 有计算器的简单操作代码

补充：Java ,  Java相关

java计算器求解 功能跑步起来 求解！！！！！

java计算器求解功能跑步起来求解！！！！！