JSP:使用EL表達式調用java函數
使用一個例子
編寫一個使用JSP表達式語言的JSP程序，輸入一個數字，提交後輸出該數字的九九乘法表。
java代碼實現打印9*9乘法表 Solution.java
package method;
public class Solution {
public static String Mul99(int n){
String result="";
for(int i=1;i<=9;i++){
int temp=i*n;
result=result+i+" X "+n+"="+temp+"<br>";
}
return result;
}
public static void main(String[] args){
System.out.print(Mul99(4));
}
}
在WEB-INF下建立文件 utils.tld
<?xml version="1.0" encoding="UTF-8" ?>
<taglib xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd"
version="2.0">
<description>MY Util 1.1 functions library</description>
<display-name>MY Util functions</display-name>
<tlib-version>1.1</tlib-version>
<short-name>mfn</short-name>
<uri>http://www.inspuruptec.com/jsp/jstl/util</uri>
<function>
<description>
mul99
</description>
<name>mul</name>
<function-class>method.Solution</function-class>
<function-signature>java.lang.String Mul99(int)</function-signature>
<example>
</example>
</function>
</taglib>
99.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme() + "://"
+ request.getServerName() + ":" + request.getServerPort()
+ path + "/";
%>
<%@taglib uri="http://www.inspuruptec.com/jsp/jstl/util" prefix="fn"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP '99.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>
<center>
<form method="POST">
輸入一個數
<input type="text" name="num">
<br>
<input type="submit" value="99乘法" />
</form>
${fn:mul((param.num)) }
</center>
</body>
</html>