自己写的一个计算器，极其简单，并且很多功能不完备

其实贴上来的代码都会有点搞笑，学了Java不过个把月，写的完全不知所云，很多基本知识还是不是很透彻，就当这段路上的勉励站吧，再接再厉！

要是不幸污了您的眼睛，别见怪啊

还望求教，指点一下，我也能进步进步，很多东西都是书上学不到的。


/**
* 做一个计算器，使其具有简单的功能
* @author：JeremyJone
* @2014.9.24
*
* 做出界面，具有显示面板，同时具有0-9，和加减乘除，还有删除和清空按钮
*
* 按下每个按钮时显示面板都具有相应功能
*
*/

package Demo1;

import javax.swing.*;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class calculator extends JFrame implements ActionListener{

String s="";
//定义两个中间缓存变量
double p1;
double p2;

//在定义一个加减乘除的符号变量，0 代表无表示，1代表加，2代表减，3代表乘，4代表除
int x=0;

JTextField text=null;

JButton jbc=null;
JButton jb1=null;
JButton jb2=null;
JButton jb3=null;
JButton jb4=null;
JButton jb5=null;
JButton jb6=null;
JButton jb7=null;
JButton jb8=null;
JButton jb9=null;
JButton jb0=null;
JButton jbdot=null;
JButton jbe=null;
JButton jbadd=null;
JButton jbminus=null;
JButton jbtime=null;
JButton jbdivide=null;

public static void main(String[] args) {
// TODO Auto-generated method stub

calculator demo1_1=new calculator();
}

//构造
public calculator()
{
JPanel mainpanel=new JPanel();

JPanel northpanel=new JPanel();
text=new JTextField();
text.setPreferredSize(new Dimension(135,50));
text.setEnabled(false);
text.setFont(new Font("黑体",30,30));
text.setHorizontalAlignment(JTextField.RIGHT); //右对齐

jbc=new JButton("C");
jbc.setPreferredSize(new Dimension(50,50));
jbc.addActionListener(this);
jbc.setActionCommand("C");

northpanel.add(text);
northpanel.add(jbc);

JPanel buttonpanel=new JPanel(new GridLayout(4,3,10,10));
jb1=new JButton("1");
jb1.addActionListener(this);
jb1.setActionCommand("1");

jb2=new JButton("2");
jb2.addActionListener(this);
jb2.setActionCommand("2");

jb3=new JButton("3");
jb3.addActionListener(this);
jb3.setActionCommand("3");

jb4=new JButton("4");
jb4.addActionListener(this);
jb4.setActionCommand("4");

jb5=new JButton("5");
jb5.addActionListener(this);
jb5.setActionCommand("5");

jb6=new JButton("6");
jb6.addActionListener(this);
jb6.setActionCommand("6");

jb7=new JButton("7");
jb7.addActionListener(this);
jb7.setActionCommand("7");

jb8=new JButton("8");
jb8.addActionListener(this);
jb8.setActionCommand("8");

jb9=new JButton("9");
jb9.addActionListener(this);
jb9.setActionCommand("9");

4000

jb0=new JButton("0");
jb0.addActionListener(this);
jb0.setActionCommand("0");

jbdot=new JButton(".");
jbdot.addActionListener(this);
jbdot.setActionCommand("dot");

jbe=new JButton("=");
jbe.addActionListener(this);
jbe.setActionCommand("e");

JPanel mathpanel=new JPanel(new GridLayout(4,1,10,10));
jbadd=new JButton("+");
jbadd.addActionListener(this);
jbadd.setActionCommand("add");

jbminus=new JButton("-");
jbminus.addActionListener(this);
jbminus.setActionCommand("minus");

jbtime=new JButton("*");
jbtime.addActionListener(this);
jbtime.setActionCommand("time");

jbdivide=new JButton("/");
jbdivide.addActionListener(this);
jbdivide.setActionCommand("divide");

buttonpanel.add(jb7);
buttonpanel.add(jb8);
buttonpanel.add(jb9);
buttonpanel.add(jb4);
buttonpanel.add(jb5);
buttonpanel.add(jb6);
buttonpanel.add(jb1);
buttonpanel.add(jb2);
buttonpanel.add(jb3);
buttonpanel.add(jbdot);
buttonpanel.add(jb0);
buttonpanel.add(jbe);

mathpanel.add(jbadd);
mathpanel.add(jbminus);
mathpanel.add(jbtime);
mathpanel.add(jbdivide);

mainpanel.add(northpanel);
mainpanel.add(buttonpanel,BorderLayout.WEST);
mainpanel.add(mathpanel,BorderLayout.EAST);

text.setText(s);

this.add(mainpanel);
this.setLocation(700, 300);
this.setSize(220, 250);
this.setResizable(false);
this.setVisible(true);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub

try {

if(e.getActionCommand().equals("C"))
{
s="";
text.setText(s);
}
else if(e.getActionCommand().equals("1"))
{
s=s+"1";
text.setText(s);
}
else if(e.getActionCommand().equals("2"))
{
s=s+"2";
text.setText(s);
}
else if(e.getActionCommand().equals("3"))
{
s=s+"3";
text.setText(s);
}
else if(e.getActionCommand().equals("4"))
{
s=s+"4";
text.setText(s);
}
else if(e.getActionCommand().equals("5"))
{
s=s+"5";
text.setText(s);
}
else if(e.getActionCommand().equals("6"))
{
s=s+"6";
text.setText(s);
}
else if(e.getActionCommand().equals("7"))
{
s=s+"7";
text.setText(s);
}
else if(e.getActionCommand().equals("8"))
{
s=s+"8";
text.setText(s);
}
else if(e.getActionCommand().equals("9"))
{
s=s+"9";
text.setText(s);
}
else if(e.getActionCommand().equals("0"))
{
s=s+"0";
text.setText(s);
}
else if(e.getActionCommand().equals("dot"))
{
if (text.getText().contains("."))
{
s=s;
text.setText(s);
}else
{
s=s+".";
text.setText(s);
}
}
else if(e.getActionCommand().equals("e"))
{
switch(x)
{
case 0:
text.setText(s);
break;
case 1:
p2=Double.valueOf(text.getText());
s=String.valueOf(p1+p2);
text.setText(s);
break;
case 2:
p2=Double.valueOf(text.getText());
s=String.valueOf(p1-p2);
text.setText(s);
break;
case 3:
p2=Double.valueOf(text.getText());
s=String.valueOf(p1*p2);
text.setText(s);
break;
case 4:
p2=Double.valueOf(text.getText());
if(p2!=0)
{
s=String.valueOf(p1/p2);
text.setText(s);
}else
{
s="ERROR";
text.setText(s);
}
break;
}
}
else if(e.getActionCommand().equals("add"))
{
p1=Double.valueOf(text.getText());
s="";
x=1;
}
else if(e.getActionCommand().equals("minus"))
{
p1=Double.valueOf(text.getText());
s="";
x=2;
}
else if(e.getActionCommand().equals("time"))
{
p1=Double.valueOf(text.getText());
s="";
x=3;
}
else if(e.getActionCommand().equals("divide"))
{
p1=Double.valueOf(text.getText());
s="";
x=4;
}

} catch (Exception e2) {
// TODO: handle exception
e2.printStackTrace();
}

}

}