package bean;
public class CalculatorBean {
private double firstNum;
private double secondNum;
private char operator='+';
private double result;
public double getFirstNum() {
return firstNum;
}
public void setFirstNum(double firstNum) {
this.firstNum = firstNum;
}
public double getSecondNum() {
return secondNum;
}
public void setSecondNum(double secondNum) {
this.secondNum = secondNum;
}
public char getOperator() {
return operator;
}
public void setOperator(char operator) {
this.operator = operator;
}
public double getResult() {
return result;
}
public void setResult(double result) {
this.result = result;
}
public void calculate(){
switch(this.operator){
case'+':{
this.result=this.firstNum+this.secondNum;
break;
}
case'-':{
this.result=this.firstNum-this.secondNum;
break;
}
case'*':{
this.result=this.firstNum*this.secondNum;
break;
}
case'/':{
if(this.secondNum==0)
{
throw new RuntimeException("被除数不能为0！");
}
this.result=this.firstNum/this.secondNum;
break;
}
default:
throw new RuntimeException("对不起，输入的运算符非法!");
}
}
}
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
</head>
<body>
<jsp:useBean id="CalculatorBean" class="bean.CalculatorBean">
</jsp:useBean>
<jsp:setProperty name="CalculatorBean" property="*" />
<%
CalculatorBean.calculate();
%>
<br />
<hr>
<br /> 计算的结果是：
<jsp:getProperty name="CalculatorBean" property="firstNum" />
<jsp:getProperty name="CalculatorBean" property="operator" />
<jsp:getProperty name="CalculatorBean" property="secondNum" />
=
<jsp:getProperty name="CalculatorBean" property="result" />
<br />
<hr>
<br />
<form action="/calculator/index.jsp" method="post"
style="text-align: center">
<table border="1" width="50%">
<tr style="text-align: center">
<td colspan="2">简单计算器</td>
<td></td>
</tr>
<tr>
<td>第一个参数</td>
<td><input type="text" name="firstNum">
</td>
</tr>
<tr>
<td>运算符</td>
<td><select name="operator">
<option value="+">+</option>
<option value="-">-</option>
<option value="*">*</option>
<option value="/">/</option>
</select></td>
</tr>
<tr>
<td>第二个参数</td>
<td><input type="text" name="secondNum">
</td>
</tr>
<tr>
<td colspan="2"><input type="submit" value="计 算">
</td>
</tr>
</table>
</form>
</body>
</html>
