Struts2 <s:iterator ><s:if> <s:esle>标签施用和jstl标签循环 _JavaScript

Struts2 <s:iterator ><s:if> <s:esle>标签使用和jstl标签循环

import java.io.Serializable;
@SuppressWarnings("all")
public class User implements Serializable{
	private int id;
	private String username;
	private String password;
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	public String getUsername() {
		return username;
	}
	public void setUsername(String username) {
		this.username = username;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
}

? ? Struts2 Action

public String list() throws Exception {
		 List list=new ArrayList();
		 User user=new User();
		 user.setPassword("admin123");
		 user.setUsername("张三");
		 list.add(user);
		 user=new User();
		 user.setPassword("admin123");
		 user.setUsername("李四");
		 list.add(user);
		 if(list!=null){
			 request.setAttribute("list", list);
			 return "userinfo";
		 }else{
			 return "input";
		 }
	}

? ?jsp页面

 <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@taglib prefix="s" uri="/struts-tags" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    
    <title>用户详情</title>
    
	<meta http-equiv="pragma" content="no-cache">
	<meta http-equiv="cache-control" content="no-cache">
	<meta http-equiv="expires" content="0">    
	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
	<meta http-equiv="description" content="This is my page">
	<!--
	<link rel="stylesheet" type="text/css" href="styles.css">
	-->

  </head>
  
  <body>
  <div align="center">
  jstl标签</br>
  	<c:choose>
    	<c:when test="${empty list}">
     			没有数据!<br>
     	</c:when>
     	<c:otherwise>
     		<c:forEach items="${list}" var="ls" >
     		 用户名：${ls["username"] }</br>
     		</c:forEach>
     	</c:otherwise>
     </c:choose>
     struts2标签</br>
       <s:iterator value="#request.list" var="ls" >
          <s:if test="#ls.username!=''"> <!--判断空串 -->
      		         <!--  用户名：<s:property value="username"/></br>方法一 -->
        		用户名：<s:property value="#ls.username"/><!--方法二 --></br>
     	  </s:if>
     	  <s:else>
     	  	  没有数据!<br>
     	  </s:else>
       </s:iterator>	
  
  </body>
</html>

?