自定义JSTL EL函数-优快云博客

JSTL的Functions标签库提供的函数有限，如果需要，可以自行开发el函数。

Function.java：

public class Function {

	public static String makeSecondUpperCase(String str){
		return str.substring(0,1)+str.substring(1,2).toUpperCase()+str.substring(2);
	}
	
	public static String cutLastChar(String str){
		return str.substring(0,str.length()-1);
	}
}

myfn.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>JSTL 1.1 functions library</description>
  <display-name>JSTL functions</display-name>
  <tlib-version>1.1</tlib-version>
  <short-name>f</short-name>
  <uri>www.dragon.com</uri>

  <function>
    <name>makeSecondUpperCase</name>
    <function-class>com.function.Function</function-class>
    <function-signature>String makeSecondUpperCase(java.lang.String)</function-signature>
  </function>
  
  <function>
    <name>cutLastChar</name>
    <function-class>com.function.Function</function-class>
    <function-signature>String cutLastChar(java.lang.String)</function-signature>
  </function>
  
  </taglib>

test.jsp：

<%@ page contentType="text/html;charset=UTF-8" pageEncoding="UTF-8"%>
<%@ taglib prefix="func" uri="www.dragon.com" %>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
${func:makeSecondUpperCase("abcdefg")}<br>
${func:cutLastChar("abcdefg")}
</body>
</html>

自定义el函数