Java实现四则运算计算器
Java实现四则运算计算器，支持带有括号的四则运算，以及求余，取倒数，开平方。原理比较简单，界面可能比较粗糙，读者仅供参考，可以自行进行修改。
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.Stack;
import javax.swing.*;
import javax.xml.soap.Text;
public class Calculator extends JFrame{
Stack priStack=new Stack();
Stack numStack=new Stack();
public Calculator() {
Container c=getContentPane();
Font font = new Font("宋体",Font.BOLD,15);
this.setLayout(new GridLayout(4,1));
JTextField jt=new JTextField("0");
JTextField jt1=new JTextField("");
jt.setFont(font);jt1.setFont(font);
jt1.setHorizontalAlignment(JTextField.RIGHT);
jt.setHorizontalAlignment(JTextField.RIGHT);
JButton data0=new JButton("0");
JButton data1=new JButton("1");
JButton data2=new JButton("2");
JButton data3=new JButton("3");
JButton data4=new JButton("4");
JButton data5=new JButton("5");
JButton data6=new JButton("6");
JButton data7=new JButton("7");
JButton data8=new JButton("8");
JButton data9=new JButton("9");
JButton left=new JButton("(");
JButton l1=new JButton("1/x");
JButton l2=new JButton(" ");
JButton l3=new JButton(" ");
JButton right=new JButton(")");
JButton point=new JButton(".");
JButton sqrt1=new JButton("sqrt");
JButton mod=new JButton("%");
JButton puls=new JButton("+");
JButton minus=new JButton("-");
JButton equ=new JButton("=");
JButton mul=new JButton("*");
JButton dvd=new JButton("/");
JButton DEC=new JButton("清零");
JButton back=new JButton("退格");
JPanel jp=new JPanel();
jp.setLayout(new GridLayout(3,5,5,5));
jp.add(data7);jp.add(data8);
jp.add(data9);jp.add(puls);jp.add(back);
jp.add(data4);
jp.add(data5);jp.add(data6);
jp.add(minus);jp.add(DEC); jp.add(data1);
jp.add(data2);jp.add(data3);
jp.add(mul);jp.add(sqrt1);
JPanel jpp=new JPanel();
jpp.setLayout(new GridLayout(2,5,5,5));
jpp.add(point);jpp.add(equ);jpp.add(data0);
jpp.add(dvd);jpp.add(mod);
jpp.add(left);jpp.add(right);
jpp.add(l1); jpp.add(l2); jpp.add(l3);
c.add(jt);c.add(jt1);c.add(jp);c.add(jpp);
this.setSize(400,500);
this.setTitle("计算器");
this.setVisible(true);
this.setResizable(false);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
sqrt1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0)
{
if(jt.getText().equals("0")) {
jt.requestFocus();
}else {
String str=jt.getText();
double t1=Double.parseDouble(str);
t1=Math.sqrt(t1);
str=String.valueOf(t1);
jt1.setText(str);
}
}
});
l1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0)
{
if(jt.getText().equals("0")) {
jt.requestFocus();
}else {
String str=jt.getText();
double t1=Double.parseDouble(str);
t1=1/t1;
str=String.valueOf(t1);
jt1.setText(str);
}
}
});
mod.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if(jt.getText().equals("0")) {
jt.requestFocus();
}else {
String str=jt.getText();
jt.setText(str+"%");
}
}
});
data0.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if(jt.getText().equals("0")) {
jt.requestFocus();
}else {
String str=jt.getText();
jt.setText(str+"0");
}
}
});
data1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if(jt.getText().equals("0")) {
jt.requestFocus();
jt.setText("");
jt.setText("1");
}else {
String str=jt.getText();
jt.setText(str+"1");
}
}
});
data2.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if(jt.getText().equals("0")) {
jt.requestFocus();
jt.setText("");
jt.setText("2");
}else {
String str=jt.getText();
jt.setText(str+"2");
}
}
});
data3.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if(jt.getText().equals("0")) {
jt.requestFocus();
jt.setText("");
jt.setText("3");
}else {
String str=jt.getText();
jt.setText(str+"3");
}
}
});
data4.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if(jt.getText().equals("0")) {
jt.requestFocus();
jt.setText("");
jt.setText("4");
}else {
String str=jt.getText();
jt.setText(str+"4");
}
}
});
data5.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if(jt.getText().equals("0")) {
jt.requestFocus();
jt.setText("");
jt.setText("5");
}else {
String str=jt.getText();
jt.setText(str+"5");
}
}
});
data6.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if(jt.getText().equals("0")) {
jt.requestFocus();
jt.setText("");
jt.setText("6");
}else {
String str=jt.getText();
jt.setText(str+"6");
}
}
});
data7.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if(jt.getText().equals("0")) {
jt.requestFocus();
jt.setText("");
jt.setText("7");
}else {
String str=jt.getText();
jt.setText(str+"7");
}
}
});
data8.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if(jt.getText().equals("0")) {
jt.requestFocus();
jt.setText("");
jt.setText("8");
}else {
String str=jt.getText();
jt.setText(str+"8");
}
}
});
data9.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if(jt.getText().equals("0")) {
jt.requestFocus();
jt.setText("");
jt.setText("9");
}else {
String str=jt.getText();
jt.setText(str+"9");
}
}
});
point.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if(jt.getText().equals("0")) {
jt.requestFocus();
jt.setText("");
jt.setText(".");
}else {
String str=jt.getText();
jt.setText(str+".");
}
}
});
puls.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if(jt.getText().equals("0")) {
jt.requestFocus();
jt.setText("");
jt.setText("+");
}else {
String str=jt.getText();
jt.setText(str+"+");
}
}
});
minus.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if(jt.getText().equals("0")) {
jt.requestFocus();
jt.setText("");
jt.setText("-");
}else {
String str=jt.getText();
jt.setText(str+"-");
}
}
});
left.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if(jt.getText().equals("0")) {
jt.requestFocus();
jt.setText("");
jt.setText("(");
}else {
String str=jt.getText();
jt.setText(str+"(");
}
}
});
right.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if(jt.getText().equals("0")) {
jt.requestFocus();
jt.setText("");
jt.setText(")");
}else {
String str=jt.getText();
jt.setText(str+")");
}
}
});
mul.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if(jt.getText().equals("0")) {
jt.requestFocus();
jt.setText("");
jt.setText("*");
}else {
String str=jt.getText();
jt.setText(str+"*");
}
}
});
dvd.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if(jt.getText().equals("0")) {
jt.requestFocus();
jt.setText("");
jt.setText("/");
}else {
String str=jt.getText();
jt.setText(str+"/");
}
}
});
//清零
DEC.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
jt.setText("0");
jt1.setText("");
}
});
equ.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
String str=jt.getText();
str=str+"#";
String temp;
StringBuffer tempNum = new StringBuffer();
StringBuffer string = new StringBuffer().append(str);
while (string.length() != 0) {
temp = string.substring(0, 1);
string.delete(0, 1);
if (!isNum(temp)) {
if (!"".equals(tempNum.toString())) {
double num =Double.parseDouble(tempNum.toString());
numStack.push(num);
tempNum.delete(0, tempNum.length());
}
while (!compare(temp.charAt(0)) && (!priStack.empty())) {
double a = (double) numStack.pop();
double b = (double) numStack.pop();
char ope = priStack.pop();
double result = 0;
switch (ope) {
case '+':
BigDecimal a1=new BigDecimal(Double.toString(a));
BigDecimal b1=new BigDecimal(Double.toString(b));
result =b1.add(a1).doubleValue();
numStack.push(result);
break;
case '-':
BigDecimal a111=new BigDecimal(Double.toString(a));
BigDecimal b111=new BigDecimal(Double.toString(b));
result =b111.subtract(a111).doubleValue();
numStack.push(result);
break;
case '*':
BigDecimal a11=new BigDecimal(Double.toString(a));
BigDecimal b11=new BigDecimal(Double.toString(b));
result =b11.multiply(a11).doubleValue();
numStack.push(result);
break;
case '/':
BigDecimal a1111=new BigDecimal(Double.toString(a));
BigDecimal b1111=new BigDecimal(Double.toString(b));
result=b1111.divide(a1111).doubleValue();
numStack.push(result);
break;
case '%':
result = b %a;
numStack.push(result);
break;
}
}
if (temp.charAt(0) != '#') {
priStack.push(new Character(temp.charAt(0)));
if (temp.charAt(0) == ')') {
priStack.pop();
priStack.pop();
}
}
} else
tempNum = tempNum.append(temp);
}
double t=numStack.pop();
jt1.setText(String.valueOf(t));
}
} );
back.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
String text=jt.getText();
int i=text.length();
if(i>0) {
text=text.substring(0,i-1);
if(text.length()==0) jt.setText("0");
else jt.setText(text);
}
}
});
}
private boolean isNum(String temp) {
return temp.matches("[0,1,2,3,4,5,6,7,8,9,.]");
}
private boolean compare(char str) {
if (priStack.empty()) {
return true;
}
char last = (char) priStack.lastElement();
if (last == '(') {
return true;
}
switch (str) {
case '#':
return false;
case '(':
return true;
case ')':
return false;
case '*': {
if (last == '+' || last == '-')
return true;
else
return false;
}
case '/': {
if (last == '+' || last == '-')
return true;
else
return false;
}
case '%': {
if (last == '+' || last == '-')
return true;
else
return false;
}
case '+':
return false;
case '-':
return false;
}
return true;
}
public static void main(String []args) {
Calculator c=new Calculator();
}
}