一：View cal.jsp
1 <%@page language="java" contentType="text/html; charset=utf-8"
2 pageEncoding="utf-8"%>
3 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
4 <html>
5 <head>
6 <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
7 <title>采用三目运算符获取运算符</title>
8 </head>
9 <body>
10 <form action="CalServlet" method="post" >
11 操作数1：<input type="text" name="num1" value="${requestScope.newCal.num1}"><br>
12 运算： <input type="radio" name="op" value="+" ${requestScope.newCal.op=="+"? "checked": " "}>+
13 <input type="radio" name="op" value="-" ${requestScope.newCal.op=="-"? "checked" : " "}>-
14 <input type="radio" name="op" value="*" ${requestScope.newCal.op=="*"? "checked" : " "}>*
15 <input type="radio" name="op" value="/" ${requestScope.newCal.op=="/"? "checked" : " "}>/<br>
16 操作数2：<input type="text" name="num2" value="${requestScope.newCal.num2}"><br>
17 <input type="submit" value="计算" ><br>
18 结果：<input type="text" value="${requestScope.newResult}">
19 </form>
20 </body>
21 </html>
二：Model Calculator.java
1 package nuc.sw.cal.bean;
2
3 public class Calculator {
4 private float num1;
5 private String op;
6 private float num2;
7 public float getNum1() {
8 return num1;
9 }
10 public void setNum1(float num1) {
11 this.num1 = num1;
12 }
13 public String getOp() {
14 return op;
15 }
16 public void setOp(String op) {
17 this.op = op;
18 }
19 public float getNum2() {
20 return num2;
21 }
22 public void setNum2(float num2) {
23 this.num2 = num2;
24 }
25
26 }
三：CalServlet.java
1 package nuc.sw.cal.servlet;
2
3 import java.io.IOException;
4 import javax.servlet.ServletException;
5 import javax.servlet.http.HttpServlet;
6 import javax.servlet.http.HttpServletRequest;
7 import javax.servlet.http.HttpServletResponse;
8
9 import nuc.sw.cal.bean.Calculator;
10
11 /**
12 * Servlet implementation class CalServlet
13 */
14 public class CalServlet extends HttpServlet {
15 private static final long serialVersionUID = 1L;
16
17 /**
18 * @see HttpServlet#HttpServlet()
19 */
20 public CalServlet() {
21 super();
22 // TODO Auto-generated constructor stub
23 }
24
25 /**
26 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
27 */
28 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
29 // TODO Auto-generated method stub
30 response.getWriter().append("Served at: ").append(request.getContextPath());
31 }
32
33 /**
34 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
35 */
36 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
37 // TODO Auto-generated method stub
38
39 //form中method若由get改变为post,只需在doPost里调用doGet方法doGet(request, response);就可以，不需要重新写方法。
40 //第一次请求为Get 之后为Post
41
42 //接受表单提交的数据，并将数据封装在bean中
43 Calculator cal=new Calculator();
44
45 cal.setNum1(Float.parseFloat(request.getParameter("num1")));
46 cal.setOp(request.getParameter("op"));
47 cal.setNum2(Float.parseFloat(request.getParameter("num2")));
48
49 float result=0;
50 switch(cal.getOp().charAt(0)){
51 //根据运算符做相应的操作
52 case ‘+‘:
53 result=cal.getNum1()+cal.getNum2();
54 break;
55 case ‘-‘:
56 result=cal.getNum1()-cal.getNum2();
57 break;
58 case ‘*‘:
59 result=cal.getNum1()*cal.getNum2();
60 break;
61 case ‘/‘:
62 result=cal.getNum1()/cal.getNum2();
63 }
64
65 //将对象和结果保存到request域中
66 //之后的模型中时常会用到传递 整个对象
67 request.setAttribute("newCal",cal);
68 request.setAttribute("newResult",result);
69 //以服务器端跳转页面
70 request.getRequestDispatcher("cal.jsp").forward(request, response);
71
72 /*
73 1.服务器端跳转 作用域为request 有返回结果而且地址栏改变，变为现页面 请求转发
74 request.getRequestDispatcher("cal.jsp").forward(request, response);
75 2.客户端跳转（2次请求） 作用域为session 无返回结果而且地址栏不变，仍是前一个页面 请求重定向
76 request.sendRedirect("cal.jsp");
77 */
78 }
79
80 }
四：项目建立结果及运行结果：
时间： 2024-11-08 13:20:57