本文实例讲述了Java swing实现的计算器功能。分享给大家供大家参考，具体如下：

package awtDemo;

import java.awt.*;

import java.awt.event.*;

import javax.swing.*;

import java.util.Vector;

public class Calculator {

String str1 = "0"; // 运算数1 初值一定为0 为了程序的安全

String str2 = "0"; // 运算数2

String signal = "+"; // 运算符

String result = "";// 结果

// 状态开关

int k1 = 1;// 开关1 用于选择输入方向 将要写入str2或 str2

int k2 = 1;// 开关2 符号键 次数 k2>1说明进行的是2+3-9+8 这样的多符号运算

int k3 = 1;// 开关3 str1 是否可以被清0 ==1时可以 !=1时不能被清0

int k4 = 1;// 开关4 str2 同上

int k5 = 1;// 开关5 控制小数点可否被录入 ==1时可以 !=1 输入的小数点被丢掉

JButton store; // 寄存器 记录 是否连续按下符号键

@SuppressWarnings("rawtypes")

Vector vt = new Vector(20, 10);

JFrame frame = new JFrame("脚本之家 - 计算器");

JTextField result_TextField = new JTextField(result, 20);// 20列

JButton clear_Button = new JButton("清除");

JButton button0 = new JButton("0");

JButton button1 = new JButton("1");

JButton button2 = new JButton("2");

JButton button3 = new JButton("3");

JButton button4 = new JButton("4");

JButton button5 = new JButton("5");

JButton button6 = new JButton("6");

JButton button7 = new JButton("7");

JButton button8 = new JButton("8");

JButton button9 = new JButton("9");

JButton button_Dian = new JButton(".");

JButton button_jia = new JButton("+");

JButton button_jian = new JButton("-");

JButton button_cheng = new JButton("*");

JButton button_chu = new JButton("/");

JButton button_dy = new JButton("=");

Calculator() {

button0.setMnemonic(KeyEvent.VK_0);// 等效键

// 其它 等效键 略,

result_TextField.setHorizontalAlignment(JTextField.RIGHT);// 文本框 右对齐

JPanel pan = new JPanel();

pan.setLayout(new GridLayout(4, 4, 5, 5));// 四行四列 边距为5像素

pan.add(button7);

pan.add(button8);

pan.add(button9);

pan.add(button_chu);

pan.add(button4);

pan.add(button5);

pan.add(button6);

pan.add(button_cheng);

pan.add(button1);

pan.add(button2);

pan.add(button3);

pan.add(button_jian);

pan.add(button0);

pan.add(button_Dian);

pan.add(button_dy);

pan.add(button_jia);

pan.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));// pan对象的边距

JPanel pan2 = new JPanel();

pan2.setLayout(new BorderLayout());

pan2.add(result_TextField, BorderLayout.WEST);

pan2.add(clear_Button, BorderLayout.EAST);

frame.setLocation(300, 200); // 主窗口 出现在位置

frame.setResizable(false); // 不能调大小

frame.getContentPane().setLayout(new BorderLayout());

frame.getContentPane().add(pan2, BorderLayout.NORTH);

frame.getContentPane().add(pan, BorderLayout.CENTER);

frame.pack();

frame.setVisible(true);

// 事件处理 程 序

// 数 字 键

class Listener implements ActionListener {

@SuppressWarnings("unchecked")

public void actionPerformed(ActionEvent e) {

String ss = ((JButton) e.getSource()).getText();

store = (JButton) e.getSource();

vt.add(store);

if (k1 == 1) {

if (k3 == 1) {

str1 = "";

k5 = 1;// 还原开关k5状态

}

str1 = str1 + ss;

k3 = k3 + 1;

result_TextField.setText(str1);// 显示

} else if (k1 == 2) {

if (k4 == 1) {

str2 = "";

k5 = 1; // 还原开关k5状态

}

str2 = str2 + ss;

k4 = k4 + 1;

result_TextField.setText(str2);

}

}

}

// 符 号

class Listener_signal implements ActionListener {

@SuppressWarnings("unchecked")

public void actionPerformed(ActionEvent e) {

String ss2 = ((JButton) e.getSource()).getText();

store = (JButton) e.getSource();

vt.add(store);

if (k2 == 1) {

k1 = 2;// 开关 k1 为1时,向数1写 为2时，向数2写

k5 = 1;

signal = ss2;

k2 = k2 + 1;// 按符号键的次数

} else {

int a = vt.size();

JButton c = (JButton) vt.get(a - 2);

if (!(c.getText().equals("+"))

&& !(c.getText().equals("-"))

&& !(c.getText().equals("*"))

&& !(c.getText().equals("/")))

{

cal();

str1 = result;

k1 = 2;// 开关 k1 为1时,向数1写 为2时，向数2写

k5 = 1;

k4 = 1;

signal = ss2;

}

k2 = k2 + 1;

}

}

}

// 清除

class Listener_clear implements ActionListener {

@SuppressWarnings("unchecked")

public void actionPerformed(ActionEvent e) {

store = (JButton) e.getSource();

vt.add(store);

k5 = 1;

k2 = 1;

k1 = 1;

k3 = 1;

k4 = 1;

str1 = "0";

str2 = "0";

signal = "";

result = "";

result_TextField.setText(result);

vt.clear();

}

}

// 等 于

class Listener_dy implements ActionListener {

@SuppressWarnings("unchecked")

public void actionPerformed(ActionEvent e) {

store = (JButton) e.getSource();

vt.add(store);

cal();

k1 = 1; // 还原开关k1状态

// str1=result;

k2 = 1;

k3 = 1;// 还原开关k3状态

k4 = 1; // 还原开关k4状态

str1 = result; // 为7+5=12 +5=17 这种计算做准备

}

}

// 小数点

class Listener_xiaos implements ActionListener {

@SuppressWarnings("unchecked")

public void actionPerformed(ActionEvent e) {

store = (JButton) e.getSource();

vt.add(store);

if (k5 == 1) {

String ss2 = ((JButton) e.getSource()).getText();

if (k1 == 1) {

if (k3 == 1) {

str1 = "";

k5 = 1; // 还原开关k5状态

}

str1 = str1 + ss2;

k3 = k3 + 1;

result_TextField.setText(str1);// 显示

} else if (k1 == 2) {

if (k4 == 1) {

str2 = "";

k5 = 1; // 还原开关k5状态

}

str2 = str2 + ss2;

k4 = k4 + 1;

result_TextField.setText(str2);

}

}

k5 = k5 + 1;

}

}

// 注册 监听器

Listener_dy jt_dy = new Listener_dy();

Listener jt = new Listener();// 临听数字键

Listener_signal jt_signal = new Listener_signal();// 临 听符 号键

Listener_clear jt_c = new Listener_clear(); // 清除键

Listener_xiaos jt_xs = new Listener_xiaos();// 小数点 键

button7.addActionListener(jt);

button8.addActionListener(jt);

button9.addActionListener(jt);

button_chu.addActionListener(jt_signal);

button4.addActionListener(jt);

button5.addActionListener(jt);

button6.addActionListener(jt);

button_cheng.addActionListener(jt_signal);

button1.addActionListener(jt);

button2.addActionListener(jt);

button3.addActionListener(jt);

button_jian.addActionListener(jt_signal);

button0.addActionListener(jt);

button_Dian.addActionListener(jt_xs);

button_dy.addActionListener(jt_dy);

button_jia.addActionListener(jt_signal);

clear_Button.addActionListener(jt_c);

// 关闭事件处理程序

frame.addWindowListener(new WindowAdapter() {

public void windowClosing(WindowEvent e) {

System.exit(0);

}

});

}

// 计 算

public void cal() {

double a2;// 运算数1

double b2;// 运算数2

String c = signal;// 运算符

double result2 = 0;// 结果

if (c.equals("")) {

result_TextField.setText("请输入运算符");

} else {

if (str1.equals(".")) // 字符串 "." 转换成double型数据时 会出错 所以手工转

str1 = "0.0";

if (str2.equals("."))

str2 = "0.0";

a2 = Double.valueOf(str1).doubleValue();

b2 = Double.valueOf(str2).doubleValue();

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

result2 = a2 + b2;

}

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

result2 = a2 - b2;

}

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

result2 = a2 * b2;

}

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

if (b2 == 0) {

result2 = 0;

} else {

result2 = a2 / b2;

}

}

result = ((new Double(result2)).toString());

result_TextField.setText(result);

}

}

@SuppressWarnings("unused")

public static void main(String[] args) {

// 界面风格，可以去除

try {

UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");

} catch (Exception e) {

e.printStackTrace();

}

Calculator cal = new Calculator();

}

}

运行效果：

PS：这里再为大家推荐几款计算工具供大家进一步参考借鉴：

希望本文所述对大家java程序设计有所帮助。