Struts2 ognl <s:sort ../>标签详解
先看最后目录结构：
给出源码：
sortTag.jsp:
<%@ page language="java" contentType="text/html; charset=gb2312"pageEncoding="gb2312"%><%@ taglib prefix="s" uri="/struts-tags"%><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><body><s:set name="frank" value="{'aefi','abc','world!','kkkkk'}" /><s:bean id="sort" name="action.SortComparator"></s:bean> <s:sort source="frank" comparator="sort"><s:iterator><tr><td><s:property /></td></tr></s:iterator></s:sort></body></html>解析：
<s:bean id="sort" name="action.SortComparator"></s:bean>即，关联相关的java类文件(此为比较器类SortComparator)。其中id属性可看作就是SortComparator的一个实例。若不加入bean标签，则出现异常：javax.servlet.jsp.JspException: comparator [null] does not implements Comparator interface由下面的"sort标签官网释义"，可知：sort标签中的comparator属性=比较器实例=bean的id属性值="sort"。
sort标签官网释义:
package action;import java.util.Comparator;public class SortComparator implements Comparator<Object> {public int compare(Object arg0, Object arg1) {return arg0.toString().compareTo(arg1.toString());}}<?xml version="1.0" encoding="gb2312"?><!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN" "http://struts.apache.org/dtds/struts-2.0.dtd"><struts> <constant name="struts.i18n.encoding" value="gb2312"/> <package name="OGNLTAG" extends="struts-default"> </package></struts>
abc aefi kkkkk world!