自定义jstl方法

	/**
	 * 自定义函数库实现
	 * @author Administrator
	 *
	 */
	public class MyFunctions {
		
		/**
		 * 方法必须是public静态的
		 * @param name
		 * @return
		 */
		public static String sayHello(String name) {
			return "Hello " + name;
		}
	}


	myfunctions.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 functions library</description>
  <display-name>my functions</display-name>
  <tlib-version>1.0</tlib-version>
  <short-name>my</short-name>
  <uri>http://www.bjsxt.com/functions</uri>
  
  <function>
    <name>sayHello</name>
    <function-class>com.bjsxt.struts.MyFunctions</function-class>
    <function-signature>java.lang.String sayHello(java.lang.String)</function-signature>
  </function>
  
</taglib>



	<%@ taglib prefix="fn"  uri="http://java.sun.com/jsp/jstl/functions"%>
	<%@ taglib prefix="my" uri="http://www.bjsxt.com/functions"%>   


		<h1>测试函数库</h1>
	<hr>
	hello.length(jsp脚本):<%=((String)request.getAttribute("hello")).length() %><br>
	hello.length(jstl函数库取长度，函数调用在el表达式中，前缀+冒号+函数名):${fn:length(hello) }<br>
	list.size:${fn:length(list) }<br>
	sayHello:${my:sayHello("Tom") }<br>
	sayHello:${my:sayHello(name) }<br>