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();
}
}
import java.awt.BorderLayout; import java.awt.Color; 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.JOptionPane; import javax.swing.JPanel; import javax.swing.JTextField; import javax.swing.border.TitledBorder; //导包 public class Jisuanqi extends JFrame implements ActionListener { //继承JFrame 实现事件监听 private JTextField reasult; private JButton btn1, btn2, btn3, btn4, btn5, btn6, btn7, btn8, btn9, btn0, btnAC, btnAdd, btnSub, btnReasult, btnD, btnAbout, btnCancel; private boolean add, sub, end, s, c; private String str; private double num1, num2; public Jisuanqi() { //构造属性 JPanel p1 = new JPanel(); JPanel p2 = new JPanel(); JPanel p3 = new JPanel(); TitledBorder tb = new TitledBorder("输出"); tb.setTitleColor(Color.BLUE); //标题边框底端线 设置颜色 btnAbout = new JButton(" 关于 "); btnCancel = new JButton("Cancel"); //两个按钮 btnCancel.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent ee) { System.exit(0); } }); //给Cancel添加事件监听 当鼠标点击时 程序结束 btnAbout.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent ee) { JOptionPane.showMessageDialog(null, "黄盖！！", "消息", JOptionPane.INFORMATION_MESSAGE); } //给“关于”添加事件监听 当鼠标点击时 弹出对话框 显示黄盖 }); p3.add(btnAbout); p3.add(btnCancel); // JPanel p4=new JPanel(); // JPanel p5=new JPanel(); // reasult.setBorder(tb); reasult = new JTextField("0", 20); reasult.setEditable(false); //设置不能修改 reasult.setHorizontalAlignment(JTextField.RIGHT); // 设置文本的水平对齐方式。 reasult.setForeground(Color.BLUE); //颜色 p1.setBorder(tb); p1.add(reasult); btn0 = new JButton("0"); btn0.addActionListener(this); btn1 = new JButton("1"); btn1.addActionListener(this); btn2 = new JButton("2"); btn2.addActionListener(this); btn3 = new JButton("3"); btn3.addActionListener(this); btn4 = new JButton("4"); btn4.addActionListener(this); btn5 = new JButton("5"); btn5.addActionListener(this); btn6 = new JButton("6"); btn6.addActionListener(this); btn7 = new JButton("7"); btn7.addActionListener(this); btn8 = new JButton("8"); btn8.addActionListener(this); btn9 = new JButton("9"); btn9.addActionListener(this); btnD = new JButton("."); btnD.addActionListener(this); btnD.setForeground(Color.RED); btnAC = new JButton("AC"); btnAC.addActionListener(this); btnAC.setBackground(Color.PINK); btnAdd = new JButton("+"); btnAdd.addActionListener(this); btnAdd.setForeground(Color.BLUE); btnSub = new JButton("—"); btnSub.addActionListener(this); btnSub.setForeground(Color.BLUE); btnReasult = new JButton("="); btnReasult.addActionListener(this); btnReasult.setForeground(Color.RED); //事件监听 + 颜色 p2.add(btn1); p2.add(btn2); p2.add(btn3); p2.add(btn4); p2.add(btn5); p2.add(btn6); p2.add(btn7); p2.add(btn8); p2.add(btn9); p2.add(btn0); p2.add(btnD); p2.add(btnAC); p2.add(btnAdd); p2.add(btnSub); p2.add(btnReasult); //面板上添加按钮 p2.setLayout(new GridLayout(5, 3)); //面板上设置对齐方式 add(p1, BorderLayout.NORTH); add(p2, BorderLayout.CENTER); add(p3, BorderLayout.SOUTH); //将p1 p2 p3 面板对象添加到JFrame } public void num(int i) { String s = null; s = String.valueOf(i); if (end) { // 如果数字输入结束，则将文本框置零，重新输入 reasult.setText("0"); end = false; } if ((reasult.getText()).equals("0")) { // 如果文本框的内容为零，则覆盖文本框的内容 reasult.setText(s); } else { // 如果文本框的内容不为零，则在内容后面添加数字 str = reasult.getText() + s; reasult.setText(str); } }/* * * String s=null; * * s=String.valueOf(i); * * str=reasult.getText()+s; * * reasult.setText(str); * * } */ public void actionPerformed(ActionEvent e) { if (e.getSource() == btn1) num(1); else if (e.getSource() == btn2) num(2); else if (e.getSource() == btn3) num(3); else if (e.getSource() == btn4) num(4); else if (e.getSource() == btn5) num(5); else if (e.getSource() == btn6) num(6); else if (e.getSource() == btn7) num(7); else if (e.getSource() == btn8) num(8); else if (e.getSource() == btn9) num(9); else if (e.getSource() == btn0) num(0); else if (e.getSource() == btnAdd) { sign(1); btnD.setEnabled(true); } else if (e.getSource() == btnSub) { sign(2); btnD.setEnabled(true); } else if (e.getSource() == btnAC) { btnD.setEnabled(true); reasult.setText("0"); } else if (e.getSource() == btnD) { str = reasult.getText(); str += "."; reasult.setText(str); btnD.setEnabled(false); } else if (e.getSource() == btnReasult) { btnD.setEnabled(true); num2 = Double.parseDouble(reasult.getText()); if (add) { num1 = num1 + num2; } else if (sub) { num1 = num1 - num2; } reasult.setText(String.valueOf(num1)); end = true; } } public void sign(int s) { if (s == 1) { add = true; sub = false; } else if (s == 2) { add = false; sub = true; } num1 = Double.parseDouble(reasult.getText()); end = true; } //设计计算的过程 public static void main(String[] args) { Jisuanqi j = new Jisuanqi(); j.setTitle("+/-简易计算器"); j.setLocation(500, 280); j.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //默认关闭可以关闭程序 j.setResizable(false); j.pack(); j.setVisible(true); } } 这个计算机，绝对让你满意
主要涉及的知识点: 类的写法, 以及方法的调用 .建议多做练习. 如果有看不懂的地方. 可以继续追问,一起讨论.
参考代码如下
//Number类
class Number {
private int n1;//私有的整型数据成员n1
private int n2;//私有的整型数据成员n2
// 通过构造函数给n1和n2赋值
public Number(int n1, int n2) {
this.n1 = n1;
this.n2 = n2;
}
// 加法
public int addition() {
return n1 + n2;
}
// 减法
public int subtration() {
return n1 - n2;
}
// 乘法
public int multiplication() {
return n1 * n2;
}
// 除法 (可能除不尽,所以使用double作为返回类型)
public double division() {
return n1 * 1.0 / n2; // 通过n1*1.0 把计算结果转换成double类型.
}
}
//Exam4 类
public class Exam4{
public static void main(String[] args) {
Number number=new Number(15, 6);//创建Number类的对象
//下面的是调用方法得到返回值进行输出显示
System.out.println("加法"+number.addition());
System.out.println("减法"+number.subtration());
System.out.println("乘法"+number.multiplication());
System.out.println("除法"+number.division());
}
}
用java写的计算器的程序，主要是通过控制台输入，主要方法是使用scanner类来接收用户从键盘输入的一个算式，通过分解算式，存入两个字符串，判断中间的的符号，进行相应计算，如下代码：
System.out.println("-----------------------------------");
System.out.println("请输入一个算术表达式，如：45*23");
Scanner in = new Scanner(System.in);//接收用户从键盘输入的字符
String str = in.nextLine();
StringBuffer buffer = new StringBuffer();//保存左侧的数字
StringBuffer buffer1 = new StringBuffer();//保存右侧的数字
char t = ' ';//保存运算符
for (int i = 0; i str.length(); i++) {
if (str.charAt(i) == '+' || str.charAt(i) == '-'
|| str.charAt(i) == '*' || str.charAt(i) == '/') {
t = str.charAt(i);//识别是什么运算符
for (int j = i + 1; j str.length(); j++) {
buffer1.append(str.charAt(j));
}
break;
} else {
buffer.append(str.charAt(i));
}
}
String c = buffer.toString();
String d = buffer1.toString();
double a = Double.parseDouble(c);
double b = Double.parseDouble(d);
double sum = 0;
if (t == '+') {
sum = a + b;
}
if (t == '-') {
sum = a - b;
}
if (t == '*') {
sum = a * b;
}
if (t == '/') {
sum = a / b;
}
System.out.println("程序运算...");
System.out.println(c+t+d+"="+sum);
System.out.print("-----------------------------------");
运行结果如下：
import java.awt.*;
import java.awt.event.*;
public class lvhaiya{
int tmp,sum,sum1,sum2=1,sum3=1;
String a,b,c,d;String s="";
Frame f=new Frame("计算器");
private String[]name={
"0","1","2","3","4","5","6","7","8","9","+","-","*","/","=","空格"
};
public Button[] button=new Button[name.length];
TextField t=new TextField("",30);
Panel p=new Panel();
Panel p1=new Panel();
Color color=new Color(100,170,90);
public lvhaiya(){
p1.setLayout(new GridLayout(5,5));
for(int i=0;iname.length;i++){
button[i]=new Button(name[i]);
p1.add(button[i]);
}
p.setLayout(new FlowLayout(FlowLayout.LEFT));
p.setBackground(color);
p.add(t);
f.add(p,BorderLayout.NORTH);
f.add(p1,BorderLayout.SOUTH);
f.pack();
f.setVisible(true);
f.addWindowListener( new WindowClose());
t.setText("0.");
for(int i=0;iname.length;i++){
button[i].addActionListener(new ButtonEventl());
}
}
public static void main(String[]args){
new lvhaiya();
}
class WindowClose extends WindowAdapter{
public void windouClosing(WindowEvent e){
System.exit(0);
}
}
class ButtonEventl implements ActionListener{
public void actionPerformed(ActionEvent e)throws ArithmeticException{
String command=e.getActionCommand();
if(command.equals("+")){
sum=Integer.parseInt(t.getText())+sum;
t.setText(String.valueOf(sum));
a=t.getText();
s="";
}
else if(command.equals("-")){
sum1=Integer.parseInt(t.getText());
b=t.getText();
s="";
}
else if(command.equals("*")){
sum2=Integer.parseInt(t.getText())*sum2;
t.setText(String.valueOf(sum2));
c=t.getText();
s="";
}
else if(command.equals("/")){
sum3=Integer.parseInt(t.getText());
d=t.getText();
s="";
}
else if(command.equals("=")){
if(a!=null){
t.setText(String.valueOf(sum+tmp));
}
if(b!=null){
t.setText(String.valueOf(sum1-tmp));
}
if(c!=null){
t.setText(String.valueOf(sum2*tmp));
}
try{
if(d!=null){
t.setText(String.valueOf(sum3/tmp));
}
}
catch(ArithmeticException a){
t.setText("除数不能为零");
}
}
else if(command.equals("空格")){
sum=0;
a=null;
b=null;
c=null;
d=null;
sum1=0;
sum2=1;
sum3=1;
tmp=0;
t.setText("0");
s="";
}
else{
s=s+command;
t.setText(s);
tmp=Integer.parseInt(s);
}
}
}
}
//按钮可以自己美化一下 希望可以帮到你
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;public class CaculatorA {
private JFrame jf;
private JButton[] jbs;
private JTextField jtf;
private JButton clear;
private double num1,num2,jieguo;
private char c;
/**
* 构造方法实例化属性
*
*/
public CaculatorA(){
jf=new JFrame("我的计算器v1.0");
jtf=new JTextField(20);
clear=new JButton("clear");
jbs=new JButton[16];
String str="123+456-789*0./=";
for(int i=0; istr.length(); i++){
jbs[i]=new JButton(str.charAt(i)+"");
}
init();
addEventHandler();
// setFont();
// setColor();
showMe();
}
/**