jsp实现网页计算器代码如下：只有两个jsp页面
myCal.jsp如下：
<%@ 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%>"> <title>My JSP 'myCal.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"> <!-- jsp页面中不可以直接使用script --> <script language="javascript"> <!-- //写一个函数判断是否两个数都有 function checkNum() { //判断num1 num2是否为空 if((form1.num1.value == "") || (form1.num2.value == "")) { window.alert("null,不能为空！"); return false; } //判断是否是数字 if(Math.round(form1.num1.value) != form1.num1.value && Math.round(form1.num2.value) != form1.num2.value) { window.alert("num1和num2不是一个数"); return false; } if(Math.round(form1.num1.value) != form1.num1.value) { window.alert("num1不是一个数"); return false; } if(Math.round(form1.num2.value) != form1.num2.value) { window.alert("num2不是一个数"); return false; } } --> </script> </head> <body> <form name="form1" action="calculator/myResult.jsp" method="post"> 请输入第一个数：<input type="text" name="num1"> <select name="flag"> <option value=+>+</option> <option value=->-</option> <option value=*>*</option> <option value=/>/</option> </select> 请输入第二个数：<input type="text" name="num2"> <input type="submit" value="计算" onclick="return checkNum();"> </form> </body> </html> myResult.jsp如下：
<%@ 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%>"> <title>My JSP 'myResult.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> <% //第1步接收到 第1个数 String s_num1 = request.getParameter("num1"); //第2步接收到 第2个数 String s_num2 = request.getParameter("num2"); //第3步接收到 运算符 String flag = request.getParameter("flag"); //第4步 计算 int num1 = Integer.parseInt(s_num1); int num2 = Integer.parseInt(s_num2); int result = 0; if(flag.equals("+")) { result = num1+num2; } else if(flag.equals("-")) { result = num1-num2; } else if(flag.equals("*")) { result = num1*num2; } else if(flag.equals("/")) { result = num1/num2; } //第5步 out.println("结果是:"+result); %> </body> </html> 虽然过程很简单但是有几个值得学习的地方：
如何判断输入的数据是不是数字：使用Math.round(form1.num1.value) != form1.num1.value 来判断；
如何获取操作值：设置name属性 flag实现。
希望本文所述对大家学习JSP编程有所帮助。
