javabean实现小计算器

来源：互联网发布：饮食男女知乎编辑：程序博客网时间：2024/06/06 08:55

1、实现javabean

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package cn.csdn.web.domain;
import java.math.BigDecimal;
public class Calculate {
private Double firstNum;
private char operator;
private Double secondNum;
private Double result;
public Calculate() {
super();
}
public Double getFirstNum() {
return firstNum;
}
public void setFirstNum(Double firstNum) {
this.firstNum = firstNum;
}
public char getOperator() {
return operator;
}
public void setOperator(char operator) {
this.operator = operator;
}
public Double getSecondNum() {
return secondNum;
}
public void setSecondNum(Double secondNum) {
this.secondNum = secondNum;
}
public Double getResult() {
return result;
}
public void setResult(Double result) {
this.result = result;
}
public Double 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) {
System.out.println("除数不能为零");
} else {
this.result = this.firstNum / this.secondNum;
BigDecimal bigDecimal = new BigDecimal(this.result);
bigDecimal = bigDecimal.setScale(2, BigDecimal.ROUND_HALF_UP);
this.result = bigDecimal.doubleValue();
}
break;
default:
System.out.println("无法判断");
break;
}
return result;
}
}

package cn.csdn.web.domain;import java.math.BigDecimal;public class Calculate {private Double firstNum;private char operator;private Double secondNum;private Double result;public Calculate() {super();}public Double getFirstNum() {return firstNum;}public void setFirstNum(Double firstNum) {this.firstNum = firstNum;}public char getOperator() {return operator;}public void setOperator(char operator) {this.operator = operator;}public Double getSecondNum() {return secondNum;}public void setSecondNum(Double secondNum) {this.secondNum = secondNum;}public Double getResult() {return result;}public void setResult(Double result) {this.result = result;}public Double 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) {System.out.println("除数不能为零");} else {this.result = this.firstNum / this.secondNum;BigDecimal bigDecimal = new BigDecimal(this.result);bigDecimal = bigDecimal.setScale(2, BigDecimal.ROUND_HALF_UP);this.result = bigDecimal.doubleValue();}break;default:System.out.println("无法判断");break;}return result;}}

2、实现jsp页面

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<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme() + "://"
+ request.getServerName() + ":" + request.getServerPort()
+ path + "/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<style>
table {
border-collapse: collapse;
}
</style>
<title>My JSP 'calculate.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<div align="center">
<h1>
计算哭器简单实现
</h1>
<hr color="red">
<div>
<jsp:useBean id="calculate" class="cn.csdn.web.domain.Calculate"></jsp:useBean>
<jsp:setProperty property="*" name="calculate" />
<%
calculate.calculate();
%>
计算结果是：
<jsp:getProperty property="firstNum" name="calculate" />
<jsp:getProperty property="operator" name="calculate" />
<jsp:getProperty property="secondNum" name="calculate" />=
<jsp:getProperty property="result" name="calculate" />
</div>
<form action="./calculate.jsp" method="post">
<table border="1px">
<caption>
计算器
</caption>
<tr>
<td colspan="2"></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 selected="selected">
+
</option>
<option>
-
</option>
<option>
*
</option>
<option>
/
</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>
</div>
</body>
</html>

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