JSTL 可以自己扩展,EL也是可以扩展的
1) 编写函数
package com.wicresoft.jpo.demo.el; import java.util.Collection; public class ELFunctions { // 函数必须是 public static 修饰 public static boolean contains(@SuppressWarnings("rawtypes") Collection collection, Object test) { if (collection == null || collection.isEmpty()) return false; return collection.contains(test); } }
2) el.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>myFunctions library</description> <display-name>JSTL functions</display-name> <tlib-version>1.1</tlib-version> <short-name>mfn</short-name> <uri>http://www.wicresoft.com/jsp/functions</uri> <function> <name>contains</name> <function-class>com.wicresoft.jpo.demo.el.ELFunctions</function-class> <function-signature>boolean contains(java.util.Collection,java.lang.Object)</function-signature> </function> </taglib>
3) el.tld 放在/WEB-INF/ 下即可
4) JSP 页面
<%@ taglib prefix="mfn" uri="http://www.wicresoft.com/jsp/functions" %> ${mfn:contains(form.xxx, yyy)