JAVA 编写计算器 要代码最简单的

学java的时候自己编的，很简单，能够连续输入计算式后进行计算

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import java.awt.BorderLayout;

import java.awt.Color;

import java.awt.FlowLayout;

import java.awt.Font;

import java.awt.GridLayout;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.text.NumberFormat;

import java.util.ArrayList;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JPanel;

import javax.swing.JTextField;

/**简易计算器，能够进行简单的计算

*

* @see 2008.12.9

*/

public class CalculatorA

implements ActionListener{

private JFrame frame;

private JTextField field;

private JButton[] allButtons;

private JButton clearButton;

// private JButton backButton;

String result="";//保存结果

StringBuilder sb = new StringBuilder();//保存要进行的计算式

int x = 0; //用来判断上一次的事件类型

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

ArrayListString arrayList = new ArrayListString();//保存计算式，通过方法进行运算

public CalculatorA(){

frame = new JFrame("我的计算器v1.1");

frame.setLocation(300,300);

field = new JTextField(25);

allButtons = new JButton[16];

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

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

}

clearButton = new JButton("CLEAR");

// backButton = new JButton("——");

init();

setFondAndColor();

addEventHander();

}

public void init(){

frame.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(field);

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

centerPanel.add(allButtons[i]);

}

southPanel.add(clearButton);

//southPanel.add(backButton);

frame.add(northPanel,BorderLayout.NORTH);

frame.add(centerPanel,BorderLayout.CENTER);

frame.add(southPanel,BorderLayout.SOUTH);

}

//设置输入字体

public void setFondAndColor(){

field.setFont(new Font("宋体",Font.BOLD,24));

field.setBackground(new Color(100,200,200));

field.setForeground(Color.RED);

//设置字体从右起始

field.setHorizontalAlignment(JTextField.RIGHT);

}

public void showMi(){

frame.pack();

frame.setResizable(false);

frame.setVisible(true);

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

public void addEventHander(){

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

allButtons[i].addActionListener(this);

}

clearButton.addActionListener(this);

// backButton.addActionListener(this);

}

@Override

public void actionPerformed(ActionEvent e) {

String str = e.getActionCommand();//取得当前事件返回的值

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

if(x == 0){ //当x为0时表示还没有进行输入

result=str;

sb.append(str);

field.setText(str);

x = 1;

}

else if(x == 1){

result = result +str;

sb.append(str);

field.setText(result);

x = 1;

}

else if(x == 2){

sb.delete(0,sb.length());

result = result+str;

sb.append(str);

field.setText(result);

x = 1;

}

else if(x == 3){

result = str;

sb.delete(0,sb.length());

arrayList.clear();

field.setText(str);

sb.append(str);

field.setText(str);

x = 1;

}

else if(x == 4){

result ="";

sb.delete(0,sb.length());

arrayList.clear();

result = str;

sb.append(str);

field.setText(str);

x = 1;

}

else{

result = result +str;

sb.append(str);

field.setText(result);

x = 1;

}

}

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

if(x == 0){

field.setText("");

x = 2;

}

else if(x == 1){

result = result + str;

arrayList.add(sb.toString());

arrayList.add(str);

sb.append(str);

field.setText(result);

x = 2;

}

else if(x == 2){

x = 2;

}

else if(x == 3){

field.setText(result+str);

arrayList.add(result);

arrayList.add(str);

result = result+str;

x = 2;

}

else if(x == 4){

result ="";

sb.delete(0,sb.length());

arrayList.clear();

x = 2;

}

else{

field.setText(result+str);

arrayList.add(result);

arrayList.add(str);

result = result+str;

x = 2;

}

}

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

if(x == 0){

field.setText("0");

arrayList.clear();

result = "0";

x = 3;

}

else if(x == 1){

try{

arrayList.add(sb.toString());

arrayList = getResult(arrayList);

result = arrayList.get(0);

field.setText(result);

arrayList.clear();

x = 3;

}catch(Exception e1){

field.setText("数据格式异常");

x = 0;

}

}

else if(x == 2){

field.setText("数据格式错误.....");

arrayList.clear();

x = 0;

}

else if(x == 3){

field.setText(result);

x = 3;

}

else if(x == 4){

result ="";

sb.delete(0,sb.length());

arrayList.clear();

x = 3;

}

else {

try{

arrayList.add(sb.toString());

arrayList = getResult(arrayList);

result = arrayList.get(0);

field.setText(result);

arrayList.clear();

x = 3;

}catch(Exception e1){

field.setText("数据格式异常");

x = 0;

}

}

}

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

arrayList.clear();

field.setText("0");

arrayList.add("0");

x = 4;

}

else{

if(result.length()1){

result = result.substring(0,result.length()-1);

if(sb.length()0){

sb.delete(sb.length()-1,sb.length());

}

else {

sb.delete(0,1);

}

field.setText(result);

x = 5;

}

else{

result = "";

sb.delete(0,sb.length());

arrayList.clear();

field.setText("0");

x = 0;

}

}

}

public static ArrayListString getResult(ArrayListString list){

String res = null;

String[] s = {"/","*","-","+"};

int i=0;

if(list.size()1){

for(;is.length;){

if(s[i].equals("/")){

for(int j=0;jlist.size();j++){

if(list.get(j).equals(s[i])){

res = Double.toString(Double.parseDouble(list.get(j-1))/Double.parseDouble(list.get(j+1)));

//本地的数据格式

NumberFormat nf = NumberFormat.getInstance();

res = nf.format(Double.parseDouble(res));

res = getChange(res);

list.set(j-1,res);

list.remove(j);

list.remove(j);

getResult(list);

}

}

i++;

}

else if(s[i].equals("*")){

for(int j=0;jlist.size();j++){

if(list.get(j).equals(s[i])){

res = Double.toString(Double.parseDouble(list.get(j-1))*Double.parseDouble(list.get(j+1)));

NumberFormat nf = NumberFormat.getInstance();

res = nf.format(Double.parseDouble(res));

res = getChange(res);

list.set(j-1,res);

list.remove(j);

list.remove(j);

getResult(list);

}

}

i++;

}

else if(s[i].equals("-")){

for(int j=0;jlist.size();j++){

if(list.get(j).equals(s[i])){

res = Double.toString(Double.parseDouble(list.get(j-1))-Double.parseDouble(list.get(j+1)));

NumberFormat nf = NumberFormat.getNumberInstance();

res = nf.format(Double.parseDouble(res));

res = getChange(res);

list.set(j-1,res);

list.remove(j);

list.remove(j);

getResult(list);

}

}

i++;

}

else {

for(int j=0;jlist.size();j++){

if(list.get(j).equals(s[i])){

res = Double.toString(Double.parseDouble(list.get(j-1))+Double.parseDouble(list.get(j+1)));

NumberFormat nf = NumberFormat.getInstance();

res = nf.format(Double.parseDouble(res));

res = getChange(res);

list.set(j-1,res);

list.remove(j);

list.remove(j);

getResult(list);

}

}

i++;

}

}

}

return list;

}

//对数字字符串进行排除不必要符号

public static String getChange(String res){

String s_temp = "";

char[] c = new char[res.length()];

for(int k=0;kc.length;k++){

c[k] = res.charAt(k);

}

for(int k=0;kc.length;k++){

if((c[k]= '0' c[k]= '9')|| c[k] == '.'){

s_temp += c[k];

}

}

return s_temp;

}

public static void main(String[] args){

new CalculatorA().showMi();

}

}

java 计算器代码

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);

}

}

java代码题 给出一段英文句子，让你把句子里的每个单词(无缩写形式) 出现次数计算出来！

等我，就写出来

import java.io.*;

import java.util.HashMap;

import java.util.Map.Entry;

public class Test {

/**

* @param args

*/

public static void main(String[] args) {

// TODO Auto-generated method stub

try {

BufferedReader br = new BufferedReader(new FileReader("C:\\text.txt"));//我就不写有界面的了，这个参数就是你英文句子文件所在位置

String sentence = null;

HashMapString,Integer map = new HashMapString, Integer();

while((sentence = br.readLine())!=null){

sentence = sentence.replaceAll("[\\pP'$']", "");

String[] words = sentence.split(" ");

for(String word:words){

if(map.get(word)==null)

map.put(word, 1);

else map.put(word, map.get(word)+1);

}

}

java.util.IteratorEntryString, Integer iter = map.entrySet().iterator();

while(iter.hasNext()){

Entry entry = (Entry) iter.next();

System.out.println(entry.getKey()+" "+entry.getValue());

}

} catch (FileNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}

JAVA计算器相关代码求大神｛详解｝

我给你找找

package com.bj.calcultor;

import java.awt.Frame;

import java.awt.GridLayout;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.awt.event.WindowAdapter;

import java.awt.event.WindowEvent;

import javax.swing.JButton;

import javax.swing.JPanel;

import javax.swing.JTextField;

public class Calcultor extends Frame implements ActionListener {

public static void main(String[] args) {//定义主方

new Calcultor();//创建匿名对象，并调用test()方法;

}

//定义按钮名称

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

JButton [] button=new JButton[arr.length];

JButton reset = new JButton("CE");

JTextField display = new JTextField(20);

//创建窗口，定义组件

//执行窗口事件:关闭窗口

private class WindowCloser extends WindowAdapter {

public void windowClosing(WindowEvent we) {

System.exit(0);

}

}

public Calcultor(){

super("计算器");//定义标题

//定义面板容器，并布局

JPanel jpanel=new JPanel(new GridLayout(4,4));

//添加按钮，并给按钮添加名称

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

button[i]= new JButton(arr[i]);

jpanel.add(button[i]);

}

JPanel panel2 = new JPanel();

panel2.add("Northr", display);

display.setEnabled(false);

panel2.add("East", reset);

this.add("North", panel2);

this.add("Center", jpanel);

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

addWindowListener(new WindowCloser());

setVisible(true);

setSize(400,400);

pack();

button[i].addActionListener(this);

reset.addActionListener(this);

display.addActionListener(this);

}

}

@Override

public void actionPerformed(ActionEvent e) {//定义事件

// TODO Auto-generated method stub

Object target=e.getSource();

String lable=e.getActionCommand();

if(target==reset){

handleReset();

}else if("0123456789.".indexOf(lable)0){

handleNumber(lable);

}else{

hadleOperator(lable);

}

}

boolean isFirstDigit=true;

private void hadleOperator(String key) {

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

number += Double.valueOf(display.getText());

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

number -= Double.valueOf(display.getText());

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

number *= Double.valueOf(display.getText());

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

number /= Double.valueOf(display.getText());

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

number =Double.valueOf(display.getText());

}

display.setText(String.valueOf(number));

operator=key;

isFirstDigit=true;

}

private void handleNumber(String key) {

if(true){

display.setText(key);//把键值设置为文本框内容

}else if(key.equals(".") display.getText().indexOf(".")0){

display.setText(display.getText()+".");//把文本框内容设置：display.getText()+"."

}else if(!key.equals(".")){

display.setText(display.getText() + key);//把文本框内容设置：display.getText()+key

isFirstDigit=false;

}

}

private void handleReset() {

display.setText("0");

isFirstDigit=true;

operator="=";

}

String operator="=";

Double number=0.0;

}

当前标题：java共词计算代码 java计算公式字符串
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