web计算器javabean和jsp实现了一下

来源：互联网发布：工程套定额软件编辑：程序博客网时间：2024/06/08 03:45

本质是jsp向jsp传值

jsp：useBean

jsp：setProperty

useBean里面的id和setProperty里面的nam是同一个类对象

setPriperty里面的param就是request.getParam

package com.jingitan.domain;import java.math.BigDecimal;public class Calculator { private String firstNum="0";private char operator ='+';private String secondNum="0";private String result;public String getFirstNum() {return firstNum;}public void setFirstNum(String firstNum) {this.firstNum = firstNum;}public char getOperator() {return operator;}public void setOperator(char operator) {this.operator = operator;}public String getSecondNum() {return secondNum;}public void setSecondNum(String secondNum) {this.secondNum = secondNum;}public String getResult() {return result;}public void setResult(String result) {this.result = result;}public void calculate(){BigDecimal first=new BigDecimal(this.firstNum);BigDecimal second=new BigDecimal(this.secondNum);switch(this.operator){case '+':{this.result=first.add(second).toString();break;}case '-':{this.result=first.subtract(second).toString();break;}case '*':{this.result=first.multiply(second).toString();break;}case '/':{this.result=first.divide(second).toString();break;}}}}

JSP

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8" contentType="text/html; charset=UTF-8"%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>        <title>Calculator</title>  </head style>    <body style="text-align:center;">    <jsp:useBean id="calculator" class="com.jingitan.domain.Calculator" scope="page"></jsp:useBean>  <jsp:setProperty name="calculator" property="*" ></jsp:setProperty>    <%  try{  calculator.calculate();  }catch(Exception e){  out.print(e.getMessage());  }     %> <br/>--------------------------------------------------------------------------------------------------------------------<br> <jsp:getProperty property="firstNum" name="calculator"/> <jsp:getProperty property="operator" name="calculator"/> <jsp:getProperty property="secondNum" name="calculator"/> = <jsp:getProperty property="result" name="calculator"/> <br/>--------------------------------------------------------------------------------------------------------------------<br>    <form action="/Calculate/index.jsp" method="post">    <table width="40%" border="1">        <tr>              <td colspan="2">简单的计算器</td>        </tr>            <tr>              <td>第一个参数</td>              <td>                  <input type="text" name="firstNum">              </td>        </tr>              <tr>          <td>操作符</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>