「java计算器」java计算器程序

admin 2023-03-19 05:08:08 617

本篇文章给大家谈谈java计算器，以及java计算器程序对应的知识点，希望对各位有所帮助，不要忘了收藏本站喔。

本文目录一览：

1、用JAVA编写一个计算器
2、如何用JAVA语言编写计算器小程序？
3、用JAVA编写的计算器
4、用java实现一个简单的计算器。
5、用Java设计一个简单的计算器。

用JAVA编写一个计算器

import javax.swing.*;

import javax.swing.border.Border;

import java.awt.*;

import java.awt.event.ActionListener;

import java.awt.event.ActionEvent;

import java.math.BigDecimal;

import java.math.RoundingMode;

import java.util.HashMap;

/**

* 我的计算器。Cheshi 继承于 JFrame，是计算器的界面

c*/

public class Cheshi extends JFrame {

private Border border = BorderFactory.createEmptyBorder(5, 5, 5, 5);

private JTextField textbox = new JTextField("0");

private CalculatorCore core = new CalculatorCore();

private ActionListener listener = new ActionListener() {

public void actionPerformed(ActionEvent e) {

JButton b = (JButton) e.getSource();

String label = b.getText();

String result = core.process(label);

textbox.setText(result);

}

};

public Cheshi(String title) throws HeadlessException {

super(title); // 调用父类构造方法

setupFrame(); // 调整窗体属性

setupControls(); // 创建控件

}

private void setupControls() {

setupDisplayPanel(); // 创建文本面板

setupButtonsPanel(); // 创建按钮面板

}

// 创建按钮面板并添加按钮

private void setupButtonsPanel() {

JPanel panel = new JPanel();

panel.setBorder(border);

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

createButtons(panel, new String[]{

"7", "8", "9", "+", "C",

"4", "5", "6", "-", "CE",

"1", "2", "3", "*", "", // 空字符串表示这个位置没有按钮

"0", ".", "=", "/", ""

});

this.add(panel, BorderLayout.CENTER);

}

/**

* 在指定的面板上创建按钮

* @param panel 要创建按钮的面板

* @param labels 按钮文字

private void createButtons(JPanel panel, String[] labels) {

for (String label : labels) {

// 如果 label 为空，则表示创建一个空面板。否则创建一个按钮。

if (label.equals("")) {

panel.add(new JPanel());

} else {

JButton b = new JButton(label);

b.addActionListener(listener); // 为按钮添加侦听器

panel.add(b);

}

// 设置显示面板，用一个文本框来作为计算器的显示部分。

private void setupDisplayPanel() {

JPanel panel = new JPanel();

panel.setLayout(new BorderLayout());

panel.setBorder(border);

setupTextbox();

panel.add(textbox, BorderLayout.CENTER);

this.add(panel, BorderLayout.NORTH);

}

// 调整文本框

private void setupTextbox() {

textbox.setHorizontalAlignment(JTextField.RIGHT); // 文本右对齐

textbox.setEditable(false); // 文本框只读

textbox.setBackground(Color.white); // 文本框背景色为白色

}

// 调整窗体

private void setupFrame() {

this.setDefaultCloseOperation(EXIT_ON_CLOSE); // 当窗体关闭时程序结束

this.setLocation(100, 50); // 设置窗体显示在桌面上的位置

this.setSize(300, 200); // 设置窗体大小

this.setResizable(false); // 窗体大小固定

}

// 程序入口

public static void main(String[] args) throws Exception {

UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());

Cheshi frame = new Cheshi("我的计算器");

frame.setVisible(true); // 在桌面上显示窗体

}

/**

* 计算器核心逻辑。这个逻辑只能处理 1~2 个数的运算。

class CalculatorCore {

private String displayText = "0"; // 要显示的文本

boolean reset = true;

private BigDecimal number1, number2;

private String operator;

private HashMapString, Operator operators = new HashMapString, Operator();

private HashMapString, Processor processors = new HashMapString, Processor();

CalculatorCore() {

setupOperators();

setupProcessors();

}

// 为每种命令添加处理方式

private void setupProcessors() {

processors.put("[0-9]", new Processor() {

public void calculate(String command) {

numberClicked(command);

}

});

processors.put("\\.", new Processor() {

public void calculate(String command) {

dotClicked();

}

});

processors.put("=", new Processor() {

public void calculate(String command) {

equalsClicked();

}

});

processors.put("[+\\-*/]", new Processor() {

public void calculate(String command) {

operatorClicked(command);

}

});

processors.put("C", new Processor() {

public void calculate(String command) {

clearClicked();

}

});

processors.put("CE", new Processor() {

public void calculate(String command) {

clearErrorClicked();

}

});

}

// 为每种 operator 添加处理方式

private void setupOperators() {

operators.put("+", new Operator() {

public BigDecimal process(BigDecimal number1, BigDecimal number2) {

return number1.add(number2);

}

});

operators.put("-", new Operator() {

public BigDecimal process(BigDecimal number1, BigDecimal number2) {

return number1.subtract(number2);

}

});

operators.put("*", new Operator() {

public BigDecimal process(BigDecimal number1, BigDecimal number2) {

return number1.multiply(number2);

}

});

operators.put("/", new Operator() {

public BigDecimal process(BigDecimal number1, BigDecimal number2) {

return number1.divide(number2, 30, RoundingMode.HALF_UP);

}

});

}

// 根据命令处理。这里的命令实际上就是按钮文本。

public String process(String command) {

for (String pattern : processors.keySet()) {

if (command.matches(pattern)) {

processors.get(pattern).calculate(command);

break;

}

return displayText;

}

// 当按下 CE 时

private void clearErrorClicked() {

if (operator == null) {

number1 = null;

} else {

number2 = null;

}

displayText = "0";

reset = true;

}

// 当按下 C 时，将计算器置为初始状态。

private void clearClicked() {

number1 = null;

number2 = null;

operator = null;

displayText = "0";

reset = true;

}

// 当按下 = 时

private void equalsClicked() {

calculateResult();

number1 = null;

number2 = null;

operator = null;

reset = true;

}

// 计算结果

private void calculateResult() {

number2 = new BigDecimal(displayText);

Operator oper = operators.get(operator);

if (oper != null) {

BigDecimal result = oper.process(number1, number2);

displayText = result.toString();

}

// 当按下 +-*/ 时（这里也可以扩展成其他中间操作符）

private void operatorClicked(String command) {

if (operator != null) {

calculateResult();

}

number1 = new BigDecimal(displayText);

operator = command;

reset = true;

}

// 当按下 . 时

private void dotClicked() {

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

displayText += ".";

} else if (reset) {

displayText = "0.";

}

reset = false;

}

// 当按下 0-9 时

private void numberClicked(String command) {

if (reset) {

displayText = command;

} else {

displayText += command;

}

reset = false;

}

// 运算符处理接口

interface Operator {

BigDecimal process(BigDecimal number1, BigDecimal number2);

}

// 按钮处理接口

interface Processor {

void calculate(String command);

}

如何用JAVA语言编写计算器小程序？

具体代码如下：

import javax.swing.*;

import java.awt.event.*;

import java.awt.*;

public class Calculator extends JFrame implements ActionListener {

private JFrame jf;

private JButton[] allButtons;

private JButton clearButton;

private JTextField jtf;

public Calculator() {

//对图形组件实例化

jf=new JFrame("任静的计算器1.0：JAVA版");

jf.addWindowListener(new WindowAdapter(){

public void windowClosing(){

System.exit(0);

}

});

allButtons=new JButton[16];

clearButton=new JButton("清除");

jtf=new JTextField(25);

jtf.setEditable(false);

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

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

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

}

public void init(){

//完成布局

jf.setLayout(new BorderLayout());

JPanel northPanel=new JPanel();

JPanel centerPanel=new JPanel();

JPanel southPanel=new JPanel();

northPanel.setLayout(new FlowLayout());

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

southPanel.setLayout(new FlowLayout());

northPanel.add(jtf);

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

centerPanel.add(allButtons[i]);

}

southPanel.add(clearButton);

jf.add(northPanel,BorderLayout.NORTH);

jf.add(centerPanel,BorderLayout.CENTER);

jf.add(southPanel,BorderLayout.SOUTH);

addEventHandler();

}

//添加事件监听

public void addEventHandler(){

jtf.addActionListener(this);

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

allButtons[i].addActionListener(this);

}

clearButton.addActionListener(new ActionListener(){

public void actionPerformed(ActionEvent e) {

// TODO Auto-generated method stub

Calculator.this.jtf.setText("");

}

});

}

//事件处理

public void actionPerformed(ActionEvent e) {

//在这里完成事件处理使计算器可以运行

String action=e.getActionCommand();

if(action=="+"||action=="-"||action=="*"||action=="/"){

}

public void setFontAndColor(){

Font f=new Font("宋体",Font.BOLD,24);

jtf.setFont(f);

jtf.setBackground(new Color(0x8f,0xa0,0xfb));

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

allButtons[i].setFont(f);

allButtons[i].setForeground(Color.RED);

}

public void showMe(){

init();

setFontAndColor();

jf.pack();

jf.setVisible(true);

jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

public static void main(String[] args){

new Calculator().showMe();

}

用JAVA编写的计算器

package main;

import java.awt.Button;

import java.awt.Color;

import java.awt.GridLayout;

import java.awt.Panel;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.math.BigDecimal;

import javax.swing.JFrame;

import javax.swing.JTextField;

public class Calculator extends JFrame implements ActionListener {

static Panel pan = new Panel();

static JTextField textField = new JTextField("0");

static Button b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, bp, ba, bs, bm, bd,

be, bc, bt, bf, bh;

private StringBuffer temp = new StringBuffer("");

private String optValue = "0";

private String optType="";

private boolean isChoiseOptType=true;

public void init() {

b0 = new Button("0");

b0.addActionListener(this);

b1 = new Button("1");

b1.addActionListener(this);

b2 = new Button("2");

b2.addActionListener(this);

b3 = new Button("3");

b3.addActionListener(this);

b4 = new Button("4");

b4.addActionListener(this);

b5 = new Button("5");

b5.addActionListener(this);

b6 = new Button("6");

b6.addActionListener(this);

b7 = new Button("7");

b7.addActionListener(this);

b8 = new Button("8");

b8.addActionListener(this);

b9 = new Button("9");

b9.addActionListener(this);

bp = new Button(".");

bp.addActionListener(this);

ba = new Button("+");

ba.addActionListener(this);

bs = new Button("-");

bs.addActionListener(this);

bm = new Button("*");

bm.addActionListener(this);

bd = new Button("/");

bd.addActionListener(this);

be = new Button("=");

be.addActionListener(this);

bc = new Button("c");

bc.addActionListener(this);

bt = new Button("退格");

bt.addActionListener(this);

bf = new Button("1/x");

bf.addActionListener(this);

bh = new Button("+/-");

bh.addActionListener(this);

this.setTitle("计算机");

this.setLayout(null);

this.setSize(260, 300);

this.setResizable(false);

GridLayout grid = new GridLayout(4, 5);

pan.setLayout(grid);

pan.setBounds(20, 60, 150, 120);

textField.setBounds(20, 35, 150, 20);

textField.setBackground(Color.cyan);

textField.setHorizontalAlignment(textField.RIGHT);

textField.setEditable(false);

pan.add(b1);

pan.add(b2);

pan.add(b3);

pan.add(ba);

pan.add(bc);

pan.add(b4);

pan.add(b5);

pan.add(b6);

pan.add(bs);

pan.add(bt);

pan.add(b7);

pan.add(b8);

pan.add(b9);

pan.add(bm);

pan.add(bf);

pan.add(b0);

pan.add(bh);

pan.add(bp);

pan.add(bd);

pan.add(be);

this.add(textField);

this.add(pan);

}

public static void main(String[] args) {

Calculator frm = new Calculator();

frm.init();

frm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

frm.setVisible(true);

}

@SuppressWarnings("static-access")

@Override

public void actionPerformed(ActionEvent e) {

String value="0";

if (e.getSource().equals(b0)) {

this.temp.append(b0.getLabel());