JSP开发模式2（计算器）

Posted 2020-08-05 Jone雄大

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CalculatorBean————————————————————————————————————————————

public class CalculatorBean {
   private String firstNum;
   private String sencondNum;
   private String operator;
   private Double result=0.0;

   public Double getResult() {
       return result;
   }
   public void setResult(Double result) {
       this.result = result;
   }
   public String getFirstNum() {
       return firstNum;
   }
   public void setFirstNum(String firstNum) {
       this.firstNum = firstNum;
   }
   public String getSencondNum() {
       return sencondNum;
   }
   public void setSencondNum(String sencondNum) {
       this.sencondNum = sencondNum;
   }
   public String getOperator() {
       return operator;
   }
   public void setOperator(String operator) {
       this.operator = operator;
   }
   public void calculate(){
       Double fisrt =Double.valueOf(firstNum);
       Double sencond =Double.valueOf(sencondNum);
       if("+".equals(operator)){
           this.result=fisrt+sencond;
       }else if("-".equals(operator)){
           this.result=fisrt-sencond;
       }else if("*".equals(operator)){
           this.result=fisrt*sencond;
       }else if("/".equals(operator)){
           this.result=fisrt/sencond;
       }
   }
   }

——————————————————————————————————————————————————————

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import com.lovo.javaBean.CalculatorBean;

/**
* Servlet implementation class CalculatorServlet
*/
@WebServlet("/CalculatorServlet.do")
public class CalculatorServlet extends HttpServlet {
   private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public CalculatorServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

   /**
   * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
   */
   protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
       doPost(request, response);
   }

   /**
   * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
   */
   protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
       request.setCharacterEncoding("UTF-8");
       //获取表单数据
       String num1=request.getParameter("num1");
       String num2=request.getParameter("num2");
       String zifu= request.getParameter("zifu");

       CalculatorBean calculatorBean= new CalculatorBean();

       calculatorBean.setFirstNum(num1);
       calculatorBean.setSencondNum(num2);
       calculatorBean.setOperator(zifu);


       calculatorBean.calculate();
       //将JavaBean对象存放到Session对象中
       HttpSession session = request.getSession();
       session.setAttribute("calculatorBean", calculatorBean);

       //控制页面转发
       request.getRequestDispatcher("newCal.jsp").forward(request, response);
   }

}

————————————————————————————————————————————————————

<%@page import="com.lovo.javaBean.CalculatorBean"%>
<%@ page language= "java" contentType="text/html;charset=UTF-8" %>
<html>
   <head>
       <meta charset="utf-8">
       <title>计算器</title>
   </head>
   <body>
   <hr>
   <%
   CalculatorBean calculatorBean = (CalculatorBean)session.getAttribute("calculatorBean");
   if(calculatorBean!=null){
       out.println(calculatorBean.getFirstNum()+calculatorBean.getOperator()+calculatorBean.getSencondNum()+"="+calculatorBean.getResult());
   }
   %>
   <form action="CalculatorServlet.do" method="post">
       <table border = 1 align="center">
       <tr>
       <td>操作数1：<input type="text" name="num1"></td>
       </tr>
       <tr>
       <td>字符：
              <select name="zifu" id="">
                    <option value="+">+</option>
                    <option value="-">-</option>
                    <option value="*">*</option>
                    <option value="/">/</option>
               </select>
           </td>
       </tr>
       <tr>
       <td>操作数2：<input type="text" name="num2"></td>
       </tr>
       <tr>
       <td colspan="2"> <input type="submit" value="结果"></td>
       </tr>
       </table>
       </form>
   </body>
</html>

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