jstl fn函数

1:在jsp中处理字符串的函数.fn()函数.要使用必须先引用标准的函数声明.
<%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %>
2.fn.contains(string,substring)
    fn.containsIgnoreCase(string,substring)
    fn.endsWith(string,suffix),
    fn.escapeXml(string)
      fn.indexOf(string,substring)
    fn.join(array,separator)
    fn.length(item)
    fn.replace(string,before,after)
    fn.split(string,separator)
    fn.startsWith(string,prefix)
    fn.substring(string,begin,after)
    fn.substringBefor(string ,substring)
    fn.substringAfter(string,substring)
    fn.toLowerCase(string)
    fn.toUpperCase(string)
    fn.toTrim(string)