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。
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