java计算器=按钮代码 java的计算器代码

求计算器的JAVA代码，要纯AWT，按钮的定义和功能多的实现麻烦注释一下，速度的

import java.awt.BorderLayout;

import java.awt.Button;

import java.awt.Frame;

import java.awt.GridBagConstraints;

import java.awt.GridBagLayout;

import java.awt.Insets;

import java.awt.Menu;

import java.awt.MenuBar;

import java.awt.MenuItem;

import java.awt.Panel;

import java.awt.TextField;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.awt.event.WindowAdapter;

import java.awt.event.WindowEvent;

import java.math.BigDecimal;

public class Calculator implements ActionListener {

    private Frame f = new Frame("计算器");

    // 菜单栏

    private MenuBar menubar = new MenuBar();

    private Menu menu1 = new Menu("查看");

    private Menu menu2 = new Menu("编辑");

    private Menu menu3 = new Menu("帮助");

    private MenuItem item1 = new MenuItem("标准型");

    private MenuItem item2 = new MenuItem("复制");

    private MenuItem item3 = new MenuItem("粘贴");

    private MenuItem item4 = new MenuItem("关于计算机");

    // 显示器面板

    private Panel panel1 = new Panel();

    private TextField label = new TextField(21);

    // 按钮面板

    private Panel panel2 = new Panel();

    private GridBagLayout gb = new GridBagLayout();

    private GridBagConstraints gbc = new GridBagConstraints();

    // 按钮内容

    private String[] cal = {"MC", "MR", "MS", "M+", "M-", "←", "CE", "C", "±", "√", "7", "8", "9", "/", "%", "4",

            "5", "6", "*", "1/x", "1", "2", "3", "-", "=", "0", ".", "+"};

    private Button[] bs = new Button[28];

    // 临时存储

    private double tmp1 = 0;

    private double tmp2 = 0;

    // 判断临时存储器中是否有值

    private boolean istmp1 = false, istmp2 = false;

    //临时保存运算符

    private String tmpoperator = "";

    // 是否清空

    private boolean isclear = false;

    public void init() {

        //设置Frame布局方式

        f.setLayout(new BorderLayout());

        // 初始化界面

        label.setEditable(false);

        label.setText("0");

        panel1.add(label);

        panel2.setLayout(gb);

                                                                  

        gbc.gridwidth = 1;

        gbc.gridheight = 1;

        gbc.fill = GridBagConstraints.BOTH;

        gbc.insets = new Insets(2, 2, 2, 2);

        gbc.gridx = 0;

        gbc.gridy = 0;

        for (int i = 0; i bs.length; i++) {

            bs[i] = new Button(cal[i]);

            int x = 1;

            String actionCommand = bs[i].getActionCommand().trim();

            if("0".equals(actionCommand)) {

                gbc.gridwidth = 2;

                x = 2;

            } else if("=".equals(actionCommand)) {

                gbc.gridheight = 2;

            }

            gb.setConstraints(bs[i], gbc);

            panel2.add(bs[i]);

            gbc.gridwidth = 1;

            gbc.gridheight = 1;

            gbc.gridx += x;

            if((i+1)%5 == 0) {

              gbc.gridx = 0;

              gbc.gridy += 1;

          }

          //为按钮添加事件

          bs[i].addActionListener(this);

        }

                                                                  

        menu1.add(item1);

        menu2.add(item2);

        menu2.add(item3);

        menu3.add(item4);

        menubar.add(menu1);

        menubar.add(menu2);

        menubar.add(menu3);

                                                                  

        //修改开始

        f.add(panel1, BorderLayout.NORTH);

        f.add(panel2, BorderLayout.CENTER);

        //修改结束

                                                                  

        f.setMenuBar(menubar);

        f.pack();

        f.setResizable(false);

        f.setLocation(400, 350);

        f.setVisible(true);

                                                                  

        //修改……关闭窗口时，停止程序

        f.addWindowListener(new WindowAdapter() {

            public void windowClosing(WindowEvent e){

                System.exit(0);

                }

        });

    }

    /**

     * 实现事件.

     * @param e

     * @see java.awt.event.ActionListener#actionPerformed(java.awt.event.ActionEvent)

     */

    public void actionPerformed(ActionEvent e) {

        // TODO Auto-generated method stub

        String numBtn = ",0,1,2,3,4,5,6,7,8,9,";

        String operator = ",+,-,*,/,";

        //按钮名称

        String btnName = e.getActionCommand();

        //文本框现有值

        String text = label.getText();

        if (numBtn.indexOf(btnName) 0) {

            /**

             * 数字操作

             */

            //首个数字不能为0

            if (text.length() == 1 "0".equals(btnName)) {

                label.setText("0");

            } else {

                if ("0".equals(text)) {

                    text = "";

                }

                if (isclear) {

                    text = "";

                    isclear = false;

                }

               label.setText(text + btnName);

                                                                          

            }

        } else if (".".equals(btnName)) {

            /**

             * 小数点操作

             */

            if (text.indexOf(".") == -1) {

                label.setText(text + btnName);

            }

        } else if (operator.indexOf(btnName) 0) {

            /**

             * 运算符操作

             */

            isclear = true;

            if (!istmp1) {

                tmp1 = Double.parseDouble(text);

                istmp1 = true;

            } else if (!istmp2) {

                tmp2 = Double.parseDouble(text);

                istmp2 = true;

            }

            if (istmp1 istmp2 !"".equals(tmpoperator)) {

                tmp1 = operator();

                label.setText(String.valueOf(tmp1));

                tmp2 = 0;

                istmp1 = true;

                istmp2 = false;

            }

            tmpoperator = btnName;

        } else if ("=".equals(btnName)) {

            if (istmp1 !istmp2) {

                tmp2 = Double.parseDouble(text);

                istmp2 = true;

            }

            if (istmp1 istmp2 !"".equals(tmpoperator)) {

                label.setText(String.valueOf(operator()));

                tmp1 = 0;

                tmp2 = 0;

                istmp1 = false;

                istmp2 = false;

            }

            isclear = true;

        }

    }

                                                              

    /**

     * @Description：计算

     * @return - 返回计算结果

     * @throws

     */

    public double operator() {

        BigDecimal dec1 = BigDecimal.valueOf(tmp1);

        BigDecimal dec2 = BigDecimal.valueOf(tmp2);

        if ("+".equals(tmpoperator)) {

            return dec1.add(dec2).doubleValue();

        } else if ("-".equals(tmpoperator)) {

            return dec1.subtract(dec2).doubleValue();

        } else if ("*".equals(tmpoperator)) {

            return dec1.multiply(dec2).doubleValue();

        } else if ("/".equals(tmpoperator)) {

            return dec1.divide(dec2).doubleValue();

        }

        return 0;

    }

    public static void main(String[] arg) {

        new Calculator().init();

    }

}

只做了+-*/操作，其他操作主要就是在事件中进行判断！

有问题再追问吧，good luck!

相关问答

Q1: 使用java语言编写一个计算器， 小数点的按钮如何用代码实现， 比如 1.1234 的输入？

if(temp==".")//判断只能输入一个小数java计算器=按钮代码，这个放在actionPerformed里java计算器=按钮代码的\x0d\x0a{\x0d\x0a for(int i=0;i

回答于 2022-11-16

Q2: java编一个计算器的代码

界面漂亮堪比系统自带计算器，功能完美加减乘除开平方等等全部具备，还有清零按钮，小数点的使用，连加连乘功能完全参考系统官方计算器经过长期调试改进而成，马上拷贝代码拿去试试看吧，绝不后悔！

代码如下：

import java.awt.*;

import java.awt.event.*;

import javax.swing.*;

import java.util.*;

public class Counter {

public static void main(String[] args) {

CounterFrame frame = new CounterFrame();

frame.show();

}

}

class CounterFrame extends JFrame {

public CounterFrame() {

JMenuBar menuBar = new JMenuBar();

JMenu menuFile = new JMenu();

JMenu menuFile1 = new JMenu();

JMenu menuFile2 = new JMenu();

JMenu menuFile3 = new JMenu();

JMenuItem menuFileExit = new JMenuItem();

menuFile.setText("文件");

menuFile1.setText("编辑");

menuFile2.setText("查看");

menuFile3.setText("帮助");

menuFileExit.setText("退出");

menuFileExit.addActionListener

(

new ActionListener() {

public void actionPerformed(ActionEvent e) {

CounterFrame.this.windowClosed();

}

}

);

menuFile.add(menuFileExit);

menuBar.add(menuFile);

menuBar.add(menuFile1);

menuBar.add(menuFile2);

menuBar.add(menuFile3);

setTitle("计算器");

setJMenuBar(menuBar);

setSize(new Dimension(400, 280));

this.getContentPane().add(new Allpanel());

this.addWindowListener

(

new WindowAdapter() {

public void windowClosing(WindowEvent e) {

CounterFrame.this.windowClosed();

}

}

);

}

protected void windowClosed() {

System.exit(0);

}

}

class Tool {

public static Tool instance;

private JTextField field;

private Tool() {

this.field=new JTextField(30);

this.field.setHorizontalAlignment(JTextField.RIGHT);

}

public static Tool getinstance()

{

if(instance==null)

{

instance=new Tool();

}

return instance;

}

public JTextField getfield()

{

return (this.field);

}

}

class Allpanel extends JPanel {

public Allpanel() {

this.setLayout(new BorderLayout(0,7));

Northpanel np=new Northpanel();

Centerpanel cp=new Centerpanel();

this.add(np,BorderLayout.NORTH);

this.add(cp,BorderLayout.CENTER);

}

}

class Centercenter extends JPanel {

static Vector Vec=new Vector();

static Vector vc=new Vector();

static Vector vc1=new Vector();

static Vector vc2=new Vector();

static Vector vc3=new Vector();

static String begin="yes";

static double add;

static double jq;

static double cs;

static double cq;

static double dy;

static String jg;

static String what;

static double tool=0;

static String to="yes";

/**

* Method Centercenter

*

*

*/

public Centercenter() {

// TODO: Add your code here

final JTextField text=Tool.getinstance().getfield();

this.setLayout(new GridLayout(4,5,3,3));

String arg[] ={"7","8","9","/","sqrt","4","5","6","*","%","1","2","3","-","1/x","0","+/-",".","+","="};

for(int i=0;i20;i++)

{

final JButton b=new JButton(arg[i]);

//this.add(new JButton(arg[i]));

this.add(b);

if(i==0||i==1||i==2||i==5||i==6||i==7||i==10||i==11||i==12||i==15)

{

b.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent e)

{

String mark=b.getText();

String ma=text.getText();

if(vc3.contains("v3"))

{

text.setText("0."+mark);

vc3.clear();

}

else if(vc.contains("a"))

{

if(vc2.contains("v2"))

{

text.setText("0."+mark);

vc.clear();

vc2.clear();

}

else

{

text.setText(mark);

vc.clear();

Vec.clear();

Vec.add(mark);

}

}

else

{

text.setText(ma.trim()+mark);

Vec.add(mark);

}

begin="no";

to="yes";

}

});

}

if(i==17)

{

b.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent e)

{

String mar=b.getText();

String m=text.getText();

if("yes".equals(begin))

{

vc3.add("v3");

}

if(vc1.contains("v1"))

{

vc2.add("v2");

vc1.clear();

}

if(!Vec.contains(".")!vc.contains("a"))

{

text.setText(m.trim()+mar);

Vec.add(".");

}

}

});

}

if(i==18)

{

b.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent e)

{

String ma=text.getText();

add=Double.parseDouble(ma);

if(what==null)

{

tool=add;

what="add";

}

else

{

tool=tool+add;

text.setText(String.valueOf((tool)));

}

vc.add("a");

vc1.add("v1");

to="+";

}

});

}

if(i==13)

{

b.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent e)

{

String ma=text.getText();

jq=Double.parseDouble(ma);

if(what==null)

{

tool=jq;

what="jq";

}

else

{

tool=tool-jq;

text.setText(String.valueOf((tool)));

}

vc.add("a");

vc1.add("v1");

to="-";

}

});

}

if(i==3)

{

b.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent e)

{

String ma=text.getText();

cq=Double.parseDouble(ma);

if(what==null)

{

tool=cq;

what="cq";

}

else

{

tool=tool/cq;

text.setText(String.valueOf((tool)));

}

vc.add("a");

vc1.add("v1");

to="/";

}

});

}

if(i==4)

{

b.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent e)

{

String ma=text.getText();

cq=Double.parseDouble(ma);

text.setText(String.valueOf(Math.sqrt(cq)));

}

});

}

if(i==8)

{

b.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent e)

{

String ma=text.getText();

cs=Double.parseDouble(ma);

if(what==null)

{

tool=cs;

what="cs";

}

else

{

tool=tool*cs;

text.setText(String.valueOf((tool)));

}

vc.add("a");

vc1.add("v1");

to="*";

}

});

}

if(i==19)

{

b.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent e)

{

String ma=text.getText();

dy=Double.parseDouble(ma);

if(what=="add")

{

jg=String.valueOf((tool+dy));

}

if(what=="jq")

{

jg=String.valueOf((tool-dy));

}

if(what=="cs")

{

jg=String.valueOf((tool*dy));

}

if(what=="cq")

{

jg=String.valueOf((tool/dy));

}

if(what==null)

{

if(to=="+")

{

tool=add;

jg=String.valueOf(tool+dy);

}

else if(to=="-")

{

tool=jq;

jg=String.valueOf(dy-tool);

}

else if(to=="*")

{

tool=cs;

jg=String.valueOf(dy*tool);

}

else if(to=="/")

{

tool=cq;

jg=String.valueOf(dy/tool);

}

else

{

jg=String.valueOf(dy);

}

}

text.setText(jg);

Vec.clear();

Vec.add(".");

vc.add("a");

vc1.add("v1");

what=null;

tool=0;

}

});

}

}

}

}

class Centernorth extends JPanel {

public Centernorth() {

final JTextField text=Tool.getinstance().getfield();

JButton jb1=new JButton("Backspace");

JButton jb2=new JButton(" CE ");

JButton jb3=new JButton(" C ");

this.add(jb1);

this.add(jb2);

this.add(jb3);

jb1.addActionListener(new ActionListener(){

public void actionPerformed(ActionEvent e)

{

String back=Tool.getinstance().getfield().getText();

text.setText(backmethod(back));

Centercenter.Vec.remove(Centercenter.Vec.size()-1);

}

});

jb3.addActionListener(new ActionListener(){

public void actionPerformed(ActionEvent e)

{

text.setText("0.");

Centercenter.Vec.clear();

Centercenter.Vec.add(".");

Centercenter.vc.add("a");

Centercenter.begin="yes";

Centercenter.vc1.clear();

Centercenter.what=null;

Centercenter.tool=0;

}

});

}

public String backmethod(String str)

{

return str.substring(0,str.length()-1);

}

}

class Centerpanel extends JPanel {

public Centerpanel() {

this.setLayout(new BorderLayout(8,7));

Centernorth cn=new Centernorth();

Centercenter cc=new Centercenter();

Centerwest cw=new Centerwest();

this.add(cn,BorderLayout.NORTH);

this.add(cc,BorderLayout.CENTER);

this.add(cw,BorderLayout.WEST);

}

}

class Centerwest extends JPanel {

public Centerwest() {

this.setLayout(new GridLayout(4,1,3,3));

this.add(new JButton("MC"));

this.add(new JButton("MR"));

this.add(new JButton("MS"));

this.add(new JButton("M+"));

}

}

class Northpanel extends JPanel {

private JTextField tf;

public Northpanel() {

tf=Tool.getinstance().getfield();

this.add(tf);

}

}

---------------------------------------------------------------------------

=============《按你要求特意后改过的最简单功能的代码如下》========================

import java.awt.*;

import java.awt.event.*;

import javax.swing.*;

import java.util.*;

public class Counter2 {

public static void main(String[] args) {

CounterFrame frame = new CounterFrame();

frame.show();

}

}

class CounterFrame extends JFrame {

public CounterFrame() {

setTitle("计算器");

setSize(new Dimension(400, 280));

this.getContentPane().add(new Allpanel());

this.addWindowListener

(

new WindowAdapter() {

public void windowClosing(WindowEvent e) {

CounterFrame.this.windowClosed();

}

}

);

}

protected void windowClosed() {

System.exit(0);

}

}

class Tool {

public static Tool instance;

private JTextField field;

private Tool() {

this.field=new JTextField(30);

this.field.setHorizontalAlignment(JTextField.RIGHT);

}

public static Tool getinstance()

{

if(instance==null)

{

instance=new Tool();

}

return instance;

}

public JTextField getfield()

{

return (this.field);

}

}

class Allpanel extends JPanel {

public Allpanel() {

this.setLayout(new BorderLayout(0,7));

Northpanel np=new Northpanel();

Centerpanel cp=new Centerpanel();

this.add(np,BorderLayout.NORTH);

this.add(cp,BorderLayout.CENTER);

}

}

class Centercenter extends JPanel {

static Vector Vec=new Vector();

static Vector vc=new Vector();

static Vector vc1=new Vector();

static Vector vc2=new Vector();

static Vector vc3=new Vector();

static String begin="yes";

static double add;

static double jq;

static double cs;

static double cq;

static double dy;

static String jg;

static String what;

static double tool=0;

static String to="yes";

/**

* Method Centercenter

*

*

*/

public Centercenter() {

// TODO: Add your code here

final JTextField text=Tool.getinstance().getfield();

this.setLayout(new GridLayout(4,5,3,3));

String arg[] ={"7","8","9","/","4","5","6","*","1","2","3","-","0","=",".","+"};

for(int i=0;i16;i++)

{

final JButton b=new JButton(arg[i]);

//this.add(new JButton(arg[i]));

this.add(b);

if(i==0||i==1||i==2||i==4||i==5||i==6||i==8||i==9||i==10||i==12)

{

b.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent e)

{

String mark=b.getText();

String ma=text.getText();

if(vc3.contains("v3"))

{

text.setText("0."+mark);

vc3.clear();

}

else if(vc.contains("a"))

{

if(vc2.contains("v2"))

{

text.setText("0."+mark);

vc.clear();

vc2.clear();

}

else

{

text.setText(mark);

vc.clear();

Vec.clear();

Vec.add(mark);

}

}

else

{

text.setText(ma.trim()+mark);

Vec.add(mark);

}

begin="no";

to="yes";

}

});

}

if(i==14)

{

b.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent e)

{

String mar=b.getText();

String m=text.getText();

if("yes".equals(begin))

{

vc3.add("v3");

}

if(vc1.contains("v1"))

{

vc2.add("v2");

vc1.clear();

}

if(!Vec.contains(".")!vc.contains("a"))

{

text.setText(m.trim()+mar);

Vec.add(".");

}

}

});

}

if(i==15)

{

b.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent e)

{

String ma=text.getText();

add=Double.parseDouble(ma);

if(what==null)

{

tool=add;

what="add";

}

else

{

tool=tool+add;

text.setText(String.valueOf((tool)));

}

vc.add("a");

vc1.add("v1");

to="+";

}

});

}

if(i==11)

{

b.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent e)

{

String ma=text.getText();

jq=Double.parseDouble(ma);

if(what==null)

{

tool=jq;

what="jq";

}

else

{

tool=tool-jq;

text.setText(String.valueOf((tool)));

}

vc.add("a");

vc1.add("v1");

to="-";

}

});

}

if(i==3)

{

b.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent e)

{

String ma=text.getText();

cq=Double.parseDouble(ma);

if(what==null)

{

tool=cq;

what="cq";

}

else

{

tool=tool/cq;

text.setText(String.valueOf((tool)));

}

vc.add("a");

vc1.add("v1");

to="/";

}

});

}

if(i==7)

{

b.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent e)

{

String ma=text.getText();

cs=Double.parseDouble(ma);

if(what==null)

{

tool=cs;

what="cs";

}

else

{

tool=tool*cs;

text.setText(String.valueOf((tool)));

}

vc.add("a");

vc1.add("v1");

to="*";

}

});

}

if(i==13)

{

b.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent e)

{

String ma=text.getText();

dy=Double.parseDouble(ma);

if(what=="add")

{

jg=String.valueOf((tool+dy));

}

if(what=="jq")

{

jg=String.valueOf((tool-dy));

}

if(what=="cs")

{

jg=String.valueOf((tool*dy));

}

if(what=="cq")

{

jg=String.valueOf((tool/dy));

}

if(what==null)

{

if(to=="+")

{

tool=add;

jg=String.valueOf(tool+dy);

}

else if(to=="-")

{

tool=jq;

jg=String.valueOf(dy-tool);

}

else if(to=="*")

{

tool=cs;

jg=String.valueOf(dy*tool);

}

else if(to=="/")

{

tool=cq;

jg=String.valueOf(dy/tool);

}

else

{

jg=String.valueOf(dy);

}

}

text.setText(jg);

Vec.clear();

Vec.add(".");

vc.add("a");

vc1.add("v1");

what=null;

tool=0;

}

});

}

}

}

}

class Centernorth extends JPanel {

public Centernorth() {

final JTextField text=Tool.getinstance().getfield();

}

}

class Centerpanel extends JPanel {

public Centerpanel() {

this.setLayout(new BorderLayout(8,7));

Centernorth cn=new Centernorth();

Centercenter cc=new Centercenter();

Centerwest cw=new Centerwest();

this.add(cn,BorderLayout.NORTH);

this.add(cc,BorderLayout.CENTER);

this.add(cw,BorderLayout.WEST);

}

}

class Centerwest extends JPanel {

public Centerwest() {

}

}

class Northpanel extends JPanel {

private JTextField tf;

public Northpanel() {

tf=Tool.getinstance().getfield();

this.add(tf);

}

}

------------------------------------------------------------

才子_辉祝您愉快！

Q3: java计算器16个按钮(要用for循环打出来的)源代码

自己写java计算器=按钮代码的java计算器=按钮代码，给你参考参考import java.awt.BorderLayout;

import java.awt.FlowLayout;

import java.awt.GridLayout;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JPanel;

import javax.swing.JTextField;public class Counter implements ActionListener{ /**

* @param args

*/

private JFrame frame;

private JTextField field;

private JButton clear_but;

private JButton[] buttons;

String str="123+456-789*0.=/";

public Counter() {

frame=new JFrame("计算器t\t\t\t\t\t\t");

field=new JTextField(15);

clear_but=new JButton("C");

buttons=new JButton[25];

for(int i=0;istr.length();i++)

{

buttons[i]=new JButton(str.substring(i, i+1));

}

field.setText("");

}

private void init(){

addEventHandler();

frame.setLayout(new BorderLayout());

JPanel n_panel=new JPanel();

JPanel c_panel=new JPanel();

n_panel.setLayout(new FlowLayout());

frame.add(n_panel,BorderLayout.NORTH);

n_panel.add(field);

n_panel.add(clear_but);

c_panel.setLayout(new GridLayout(4,4));

for(int i=0;i16;i++)

{

c_panel.add(buttons[i]);

}

frame.add(c_panel, BorderLayout.CENTER);

}

public void showMe(){

init();

frame.setSize(300, 240);

//frame.pack();// frame.setLocation(400,360);

frame.setVisible(true);

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

private void addEventHandler(){

//clear_but.addActionListener(new MyActionListener());

clear_but.addActionListener(new ActionListener(){

public void actionPerformed(ActionEvent e) {

field.setText("");

}

});

for(int i=0;i16;i++)

{

final int in=i;

buttons[i].addActionListener(this);

// @Override

// public void actionPerformed(ActionEvent e) {

// System.out.print(e.getActionCommand());

// //System.out.print(str.substring(in, in+1));

// }

//

}

}

String num="";

String flag="";

//@Override

public void actionPerformed(ActionEvent e) {

String str=e.getActionCommand();

if(str.equals("=")){

Double a=Double.valueOf(num);

Double b=Double.valueOf(field.getText());

double sum=0;

if(flag.equals("+")){

sum=a+b;

field.setText(sum+"");

}

if(flag.equals("-")){

sum=a-b;

field.setText(""+sum);

}

if(flag.equals("*")){

sum=a*b;

field.setText(""+sum);

}

if(flag.equals("/")){

sum=a/b;

field.setText(""+sum);

}

System.out.println(a+flag+b+"="+sum);

}

else if(".0123456789".indexOf(str)!=-1){

String newtext=field.getText();

newtext+=str;

field.setText(newtext);

//System.out.print(str);

}

else if(str.matches("[+*-/]{1}")){

//else if("+-*/".indexOf(str)!=-1){

num=field.getText();

field.setText("");

flag=str;

// System.out.print(str);

}

}

public static void main(String[] args) {

new Counter().showMe();

}}

Q4: 用java.EE编写计算器程序代码

java EE是java企业级开发平台的意思，实在是看不出跟计算器这种小程序有什么关联。不知道楼主要找的是不是这个。

package ex1;

import java.awt.BorderLayout;

import java.awt.Color;

import java.awt.Dimension;

import java.awt.Font;

import java.awt.GridLayout;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.text.DecimalFormat;

import javax.swing.BorderFactory;

import javax.swing.ButtonGroup;

import javax.swing.JButton;

import javax.swing.JCheckBoxMenuItem;

import javax.swing.JFrame;

import javax.swing.JMenu;

import javax.swing.JMenuBar;

import javax.swing.JMenuItem;

import javax.swing.JPanel;

import javax.swing.JRadioButtonMenuItem;

import javax.swing.JTextField;

public class Calcutor extends JFrame {

private JTextField tf;

private JPanel panel1, panel2, panel3, panel4;

private JMenuBar myBar;

private JMenu menu1, menu2, menu3;

private JMenuItem editItem1, editItem2, help1, help2, help3;

private JRadioButtonMenuItem seeItem1, seeItem2;//单选框

private JCheckBoxMenuItem seeItem3;//复选框

private ButtonGroup bgb;

private String back;

private boolean IfResult = true, flag = false;

private String oper = "=";

private double result = 0;

private Num numActionListener;

private DecimalFormat df;

public Calcutor(){

super("科学计算器");//设置标题栏

df = new DecimalFormat("#.####");//保留四位小数

this.setLayout(new BorderLayout(10, 5));

panel1 = new JPanel(new GridLayout(1, 3, 10, 10));

panel2 = new JPanel(new GridLayout(5, 6, 5, 5));//5行6列

panel3 = new JPanel(new GridLayout(5, 1, 5, 5));

panel4 = new JPanel(new BorderLayout(5, 5));

/**

* 菜单栏

*/

myBar = new JMenuBar();

menu1 = new JMenu("编辑(E)");

menu2 = new JMenu("查看(V)");

menu3 = new JMenu("帮助(H)");

menu1.setFont(new Font("宋体", Font.PLAIN, 12));

menu2.setFont(new Font("宋体", Font.PLAIN, 12));

menu3.setFont(new Font("宋体", Font.PLAIN, 12));

/**

* 编辑栏

*/

editItem1 = new JMenuItem("复制(C) Ctrl+C");

editItem2 = new JMenuItem("粘贴(P) Ctrl+V");

editItem1.setFont(new Font("宋体",Font.PLAIN,12));

editItem2.setFont(new Font("宋体",Font.PLAIN,12));

/**

* 查看栏

*/

seeItem1 = new JRadioButtonMenuItem("科学型(T)");

seeItem2 = new JRadioButtonMenuItem("标准型(S)");

seeItem3 = new JCheckBoxMenuItem("数字分组(I)");

seeItem1.setFont(new Font("宋体",Font.PLAIN,12));

seeItem2.setFont(new Font("宋体",Font.PLAIN,12));

seeItem3.setFont(new Font("宋体",Font.PLAIN,12));

/**

* 帮助栏

*/

help1 = new JMenuItem("帮助主题(H)");

help2 = new JMenuItem("关于计算器(A)");

help1.setFont(new Font("宋体",Font.PLAIN,12));

help2.setFont(new Font("宋体",Font.PLAIN,12));

bgb = new ButtonGroup();//选项组

menu1.add(editItem1);

menu1.add(editItem2);

menu2.add(seeItem1);

menu2.add(seeItem2);

menu2.addSeparator();//添加一条分割线

menu2.add(seeItem3);

menu3.add(help1);

menu3.addSeparator();//添加一条分割线

menu3.add(help2);

myBar.add(menu1);

myBar.add(menu2);

myBar.add(menu3);

this.setJMenuBar(myBar);

numActionListener = new Num();//实现数字监听

/**

* 文本域，即为计算器的屏幕显示区域

*/

tf = new JTextField();

tf.setEditable(false);//文本区域不可编辑

tf.setBackground(Color.white);//文本区域的背景色

tf.setHorizontalAlignment(JTextField.RIGHT);//文字右对齐

tf.setText("0");

tf.setBorder(BorderFactory.createLoweredBevelBorder());

init();//对计算器进行初始化

}

/**

* 初始化操作

* 添加按钮

*/

private void init(){

addButton(panel1, "Backspace", new Clear(), Color.red);

addButton(panel1, "CE", new Clear(), Color.red);

addButton(panel1, "C", new Clear(), Color.red);

addButton(panel2, "1/x", new Signs(), Color.magenta);

addButton(panel2, "log", new Signs(), Color.magenta);

addButton(panel2, "7", numActionListener, Color.blue);

addButton(panel2, "8", numActionListener, Color.blue);

addButton(panel2, "9", numActionListener, Color.blue);

addButton(panel2, "÷", new Signs(), Color.red);

addButton(panel2, "n!", new Signs(), Color.magenta);

addButton(panel2, "sqrt", new Signs(), Color.magenta);

addButton(panel2, "4", numActionListener, Color.blue);

addButton(panel2, "5", numActionListener, Color.blue);

addButton(panel2, "6", numActionListener, Color.blue);

addButton(panel2, "×", new Signs(), Color.red);

addButton(panel2, "sin", new Signs(), Color.magenta);

addButton(panel2, "x^2", new Signs(), Color.magenta);

addButton(panel2, "1", numActionListener, Color.blue);

addButton(panel2, "2", numActionListener, Color.blue);

addButton(panel2, "3", numActionListener, Color.blue);

addButton(panel2, "-", new Signs(), Color.red);

addButton(panel2, "cos", new Signs(), Color.magenta);

addButton(panel2, "x^3", new Signs(), Color.magenta);

addButton(panel2, "0", numActionListener, Color.blue);

addButton(panel2, "-/+", new Clear(), Color.blue);

addButton(panel2, ".", new Dot(), Color.blue);

addButton(panel2, "+", new Signs(), Color.red);

addButton(panel2, "tan", new Signs(), Color.magenta);

addButton(panel2, "%", new Signs(), Color.magenta);

addButton(panel2, "π", numActionListener, Color.orange);

addButton(panel2, "e", numActionListener, Color.orange);

addButton(panel2, "′″", new Signs(), Color.orange);

addButton(panel2, "=", new Signs(), Color.red);

JButton btns = new JButton("计算器");

btns.setBorder(BorderFactory.createLoweredBevelBorder());

btns.setEnabled(false);//按钮不可操作

btns.setPreferredSize(new Dimension(20, 20));

panel3.add(btns);//加入按钮

addButton(panel3, "MC", null, Color.red);

addButton(panel3, "MR", null, Color.red);

addButton(panel3, "MS", null, Color.red);

addButton(panel3, "M+", null, Color.red);

panel4.add(panel1, BorderLayout.NORTH);

panel4.add(panel2, BorderLayout.CENTER);

this.add(tf, BorderLayout.NORTH);

this.add(panel3, BorderLayout.WEST);

this.add(panel4);

pack();

this.setResizable(false);//窗口不可改变大小

this.setLocation(300, 200);

this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

/**

* 统一设置按钮的的使用方式

* @param panel

* @param name

* @param action

* @param color

*/

private void addButton(JPanel panel, String name, ActionListener action, Color color){

JButton bt = new JButton(name);

panel.add(bt);//在面板上增加按钮

bt.setForeground(color);//设置前景（字体）颜色

bt.addActionListener(action);//增加监听事件

}

/**

* 计算器的基础操作（+ - × ÷）

* @param x

*/

private void getResult (double x){

if(oper == "+"){result += x;}

else if(oper == "-"){result -= x;}

else if(oper == "×"){result *= x;}

else if(oper == "÷"){result /= x;}

else if(oper == "="){result = x;}

tf.setText(df.format(result));

}

/**

* 运算符号的事件监听

*/

class Signs implements ActionListener{

public void actionPerformed(ActionEvent e) {

/*

* 用ActionEvent对象的getActionCommand()方法

* 取得与引发事件对象相关的字符串

*/

String str = e.getActionCommand();

/* sqrt求平方根 */

if(str.equals("sqrt")){

double i = Double.parseDouble(tf.getText());

if(i=0){

/*

* String.valueOf() 转换为字符串

* df.format() 按要求保留四位小数

* Math.sqrt() 求算数平方根

*/

tf.setText(String.valueOf(df.format(Math.sqrt(i))));

}

else{

tf.setText("负数不能开平方根");

}

}

/* log求常用对数 */

else if(str.equals("log")){

double i = Double.parseDouble(tf.getText());

if(i0){

tf.setText(String.valueOf(df.format(Math.log(i))));

}else{

tf.setText("负数不能求对数");

}

}

/* %求百分比 */

else if(str.equals("%")){

tf.setText(df.format(Double.parseDouble(tf.getText()) / 100));

}

/* 1/x求倒数 */

else if(str.equals("1/x")){

if(Double.parseDouble(tf.getText()) == 0){

tf.setText("除数不能为零");

}else{

tf.setText(df.format(1 / Double.parseDouble(tf.getText())));

}

}

/* sin求正弦函数 */

else if(str.equals("sin")){

double i = Double.parseDouble(tf.getText());

tf.setText(String.valueOf(df.format(Math.sin(i))));

}

/* cos求余弦函数 */

else if(str.equals("cos")){

double i = Double.parseDouble(tf.getText());

tf.setText(String.valueOf(df.format(Math.cos(i))));

}

/* tan求正切函数 */

else if(str.equals("tan")){

double i = Double.parseDouble(tf.getText());

tf.setText(String.valueOf(df.format(Math.tan(i))));

}

/* n!求阶乘 */

else if(str.equals("n!")){

double i = Double.parseDouble(tf.getText());

if((i%2==0)||(i%2==1))//判断为整数放进行阶乘操作

{

int j = (int)i;//强制类型转换

int result=1;

for(int k=1;k=j;k++)

result *= k;

tf.setText(String.valueOf(result));

}

else

{

tf.setText("无法进行阶乘");

}

}

/* x^2求平方 */

else if(str.equals("x^2")){

double i = Double.parseDouble(tf.getText());

tf.setText(String.valueOf(df.format(i*i)));

}

/* x^3求立方 */

else if(str.equals("x^3")){

double i = Double.parseDouble(tf.getText());

tf.setText(String.valueOf(df.format(i*i*i)));

}

/* ′″角度转换 */

/**

* 将角度值转换成弧度值，方便三角函数的计算

*/

else if(str.equals("′″")){

double i = Double.parseDouble(tf.getText());

tf.setText(String.valueOf(i/180*Math.PI));

}

else{

if(flag){

IfResult = false;

}

if(IfResult){

oper = str;

}else{

getResult(Double.parseDouble(tf.getText()));

oper = str;

IfResult = true;

}

}

}

}

/**

* 清除按钮的事件监听

*/

class Clear implements ActionListener{

public void actionPerformed(ActionEvent e) {

/*

* 用ActionEvent对象的getActionCommand()方法

* 取得与引发事件对象相关的字符串

*/

String str = e.getActionCommand();

if(str == "C"){

tf.setText("0");

IfResult = true;

result = 0;

}else if(str == "-/+"){

double i = 0 - Double.parseDouble(tf.getText().trim());

tf.setText(df.format(i));

}else if(str == "Backspace"){

if(Double.parseDouble(tf.getText()) 0){

if(tf.getText().length() 1){

tf.setText(tf.getText().substring(0, tf.getText().length() - 1));

//使用退格删除最后一位字符

}else{

tf.setText("0");

IfResult = true;

}

}else{

if(tf.getText().length() 2){

tf.setText(tf.getText().substring(0, tf.getText().length() - 1));

}else{

tf.setText("0");

IfResult = true;

}

}

}else if(str == "CE"){

tf.setText("0");

IfResult = true;

}

}

}

/**

* 数字输入的事件监听

*/

class Num implements ActionListener{

public void actionPerformed(ActionEvent e) {

String str = e.getActionCommand();

if(IfResult){

tf.setText("");

IfResult = false;

}

if(str=="π")

{

tf.setText(String.valueOf(Math.PI));

}

else if(str=="e")

{

tf.setText(String.valueOf(Math.E));

}

else{

tf.setText(tf.getText().trim() + str);

if(tf.getText().equals("0")){

tf.setText("0");

IfResult = true;

flag = true;

}

}

}

}

/**

* 小数点的事件监听

*/

class Dot implements ActionListener{

public void actionPerformed(ActionEvent e) {

IfResult = false;

if(tf.getText().trim().indexOf(".") == -1){

tf.setText(tf.getText() + ".");

}

}

}

/**

* main方法

*/

public static void main(String[] args) {

new Calcutor().setVisible(true);

}

}

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