功能概述
可以實現兩個數的加、減、乘、除、平均數運算！
實現樣式
代碼
代碼結構
代碼實現
JavaBean
package bean;
/**
* @ClassName Score
* @Description TODO
* @Author L
* @Date 2020.06.28 17:32
* @Version 1.0
* @Remark
**/
public class Calculator {
private String firstNum;
private String secondNum;
private String operator;
private double result;
public String getFirstNum() {
return firstNum;
}
public void setFirstNum(String firstNum) {
this.firstNum = firstNum;
}
public String getSecondNum() {
return secondNum;
}
public void setSecondNum(String secondNum) {
this.secondNum = secondNum;
}
public String getOperator() {
return operator;
}
public void setOperator(String operator) {
this.operator = operator;
}
public double getResult() {
return result;
}
public void setResult(double result) {
this.result = result;
}
public double calc(){
double fir = Double.parseDouble(firstNum);
double sec = Double.parseDouble(secondNum);
if (operator.equals("+")){
result = fir + sec;
} else if(operator.equals("-")){
result = fir - sec;
} else if(operator.equals("*")){
result = fir * sec;
} else if(operator.equals("/")){
result = fir / sec;
} else if(operator.equals("avg")){
result = (fir + sec) / 2;
}
return result;
}
}
JSP頁面
<%@ page import="bean.Calculator" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%-- id="id" class="bean 編譯的類" scope="bean 作用域" --%>
<jsp:useBean id="calc" scope="request" class="bean.Calculator">
<%-- name="bean的id" property="屬性名" --%>
<jsp:setProperty name="calc" property="*" />
</jsp:useBean>
<html>
<head>
<title>簡易計算器</title>
</head>
<body>
<%
// 接收方法的返回值
String result = "0.0";
try{
if (calc.getOperator().equals("avg")){
result = "平均數 = "+ calc.calc();
}
// 1 + 1 = 2
result = calc.getFirstNum() + calc.getOperator() + calc.getSecondNum() +"="+ calc.calc();
}catch (Exception e){
result = e.getMessage();
}
%>
<div align="center">
<form action="Calc.jsp" method="get">
<table border="1">
<tr>
<td>計算</td>
<td>輸入值</td>
</tr>
<tr>
<td>第一個數</td>
<td><input type="text" name="firstNum" /></td>
</tr>
<tr>
<td>運算符號</td>
<td>
<select name="operator">
<option value="+">+</option>
<option value="-">-</option>
<option value="*">*</option>
<option value="/">/</option>
<option value="avg">平均數</option>
</select>
</td>
</tr>
<tr>
<td>第二個數</td>
<td><input type="text" name="secondNum" /></td>
</tr>
<td>結果</td>
<td><input type="text" value=<%= result%> /></td>
</tr>
</tr>
<td colspan="2" align="center">
<input type="submit" value="提交" />
</td>
</tr>
</table>
</form>
</div>
</body>
</html>
web.xml配置
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
version="4.0">
<!--設置啓動頁面-->
<welcome-file-list>
<welcome-file>Calc.jsp</welcome-file>
</welcome-file-list>
</web-app>
總結
- jsp標籤
- javabean的創建