Java编的简单计算器

import java.awt.*;
import java.awt.event.*;
import java.lang.*;
import javax.swing.*;
import java.util.*;
import java.math.*;
public class Cal{
static Frame frm=new Frame("Calculator");//frame
static JTextField txt=new JTextField("0");//text
static JTextField time=new JTextField("00:00:00");//time
//static Date hour=new Date(),min=new Date(),sec=new Date();
static Button btn[]=new Button[30];//button
static Dialog dlg=new Dialog(frm);//dlg
static Thread thd=new Thread();
static String btn_name[]={"MC","7","8","9","/","sqrt","MR","4","5","6","*","%",
"MS","1","2","3","-","1/x","M+","0","+/-",".","+","=",
"Backspace","CE","C","close","cancel"};//button_name Array_size=29
static String op="";
static double ans=0,x=0,y=0;//ans
static StringBuffer str=new StringBuffer("");//Str_buffer to read number
static Panel pn1=new Panel();//panel
static Panel pn2=new Panel();

public Cal(){//构造函数
//frame
frm.setLayout(null);
frm.setLocation(250,250);
frm.setSize(350,300);
frm.setBackground(Color.DARK_GRAY);
frm.setResizable(false);
frm.setVisible(true);
frm.addWindowListener(new WinLis());
//text
txt.setForeground(Color.yellow);
txt.setBackground(Color.gray);
txt.setBounds(90,40,230,30);//输出显示
txt.setHorizontalAlignment(JTextField.RIGHT);
txt.setEditable(false);
frm.add(txt);
time.setForeground(Color.yellow);
time.setBackground(Color.gray);
time.setBounds(20,40,60,30);//时间显示
time.setHorizontalAlignment(JTextField.CENTER);
time.setEditable(false);
frm.add(time);

//panel&&button
GridLayout grid1=new GridLayout(4,6);
GridLayout grid2=new GridLayout(1,3);
pn1.setLayout(grid1);
pn2.setLayout(grid2);
pn1.setBounds(20,120,300,150);
pn2.setBounds(20,80,300,30);
for(int i=0;i<24;i++){
btn[i]=new Button(btn_name[i]);
btn[i].setForeground(Color.red);
btn[i].setBackground(Color.yellow);
btn[i].addActionListener(new ActLis());
pn1.add(btn[i]);
}
frm.add(pn1);
for(int i=24;i<27;i++){
btn[i]=new Button(btn_name[i]);
btn[i].setForeground(Color.red);
btn[i].setBackground(Color.blue);
btn[i].addActionListener(new ActLis());
pn2.add(btn[i]);
}
frm.add(pn2);
//dialog &btn
btn[27]=new Button(btn_name[27]);
btn[28]=new Button(btn_name[28]);
btn[27].setBackground(Color.blue);
btn[28].setBackground(Color.blue);
btn[27].setForeground(Color.yellow);
btn[28].setForeground(Color.yellow);
dlg.setTitle("确定要关闭");
dlg.setSize(200,150);
dlg.setLayout(new FlowLayout(FlowLayout.CENTER,5,30));
dlg.setBackground(Color.white);
dlg.add(btn[27]);
dlg.add(btn[28]);
}
static class thread extends Thread{//时间显示线程
public thread(){
thd=new Thread(this);
thd.start();
}
public void run(){
while(true){
Integer a=new Date().getHours(),b=new Date().getMinutes(),c=new Date().getSeconds();
String aa=new String(""),bb=new String(""),cc=new String("");
if(a<10) aa="0"+a.toString(); else aa=a.toString();
if(b<10) bb="0"+b.toString(); else bb=b.toString();
if(c<10) cc="0"+c.toString(); else cc=c.toString();
time.setText(aa+":"+bb+":"+cc);
try{
thd.sleep(100);
}
catch(InterruptedException ie){
System.out.println(""+ie);
}
}
}
}
public class WinLis extends WindowAdapter{//WinLis
public void windowClosing(WindowEvent e1){
//frm.dispose();
//System.exit(0);
dlg.setLocation(200,300);
dlg.show(true);
}
}
static class ActLis implements ActionListener{ //ActionListener
public void actionPerformed(ActionEvent e2){
Button bt=(Button)e2.getSource();
if(bt==btn[27]){
frm.dispose();
System.exit(0);
}
else if(bt==btn[28]) dlg.hide();
else if(bt==btn[24]){//"Backspace"键
if(!txt.getText().trim().equals("0")){
if(str.length()!=1){
txt.setText(str.delete(str.length()-1,str.length()).toString());
}
else{
txt.setText("0");
str.setLength(0);//str长度清零
}
}
y=Double.parseDouble(txt.getText().trim());
}
else if(bt==btn[25] || bt==btn[26]){txt.setText("0");str.setLength(0);}// "CE"or"C"
//else if(bt==btn[0]){}//btn[0]"MC" btn[6]"MR" btn[12]"MS" btn[18]"M+"
else if(bt==btn[4]) {// "/" 号
op="/";
x=Double.parseDouble(txt.getText().trim());y=0;
str.setLength(0);
}
else if(bt==btn[5]){// "sqrt"号
x=Double.parseDouble(txt.getText().trim());y=0;
if(x<0) txt.setText("invalid");
else txt.setText(""+Math.sqrt(x));
str.setLength(0);
}
else if(bt==btn[10]){// "*"号
op="*";
x=Double.parseDouble(txt.getText().trim());y=0;
str.setLength(0);
}
else if(bt==btn[11]) {// "%"号
x=Double.parseDouble(txt.getText().trim());y=0;
txt.setText(""+x/100);
str.setLength(0);
}
else if(bt==btn[16]){// "-"号
op="-";
x=Double.parseDouble(txt.getText().trim());y=0;
str.setLength(0);
}
else if(bt==btn[17]){// "1/x"号
x=Double.parseDouble(txt.getText().trim());y=0;
if(x==0) txt.setText("invalid");
else txt.setText(""+1/x);
str.setLength(0);
}
else if(bt==btn[22]){// "+"号
op="+";
x=Double.parseDouble(txt.getText().trim());y=0;
str.setLength(0);
}
else if(bt==btn[21]){// "." 号
if(txt.getText().trim().indexOf('.')==-1) txt.setText(str.append(".").toString());
else{
txt.setText("invalid");
str.setLength(0);
x=0;y=0;
}
}
else if(bt==btn[23]){// "="号
if(y==0 && op=="/") txt.setText("invalid");
else txt.setText(""+calculate());
str.setLength(0);
x=Double.parseDouble(txt.getText().trim());y=0;op="";
}
else{//按下数字键
txt.setText(str.append(e2.getActionCommand()).toString());
y=Double.parseDouble(txt.getText().trim());
}
}
public double calculate(){
if(op=="+") return x+y;
else if(op=="-") return x-y;
else if(op=="*") return x*y;
else if(op=="") return y;
else{
//if(y==0) {txt.setText("invalid");
return x/y;
}
}
}

public static void main(String args[]){
Cal calculator=new Cal();
thread new_thd=new thread();
}
}