1 <%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> 2 <%@ taglib prefix="s" uri="/struts-tags"%> 3 4 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 5 <html> 6 <head> 7 <title>My JSP 'login.jsp' starting page</title> 8 9 <meta http-equiv="pragma" content="no-cache"> 10 <meta http-equiv="cache-control" content="no-cache"> 11 <meta http-equiv="expires" content="0"> 12 13 </head> 14 15 <body> 16 <s:if test="#session.username==null"> 17 <s:text name="struts.myssh.login"/> 18 <hr> 19 <s:form action="Login" method="post"> 20 ${log_err} 21 <s:textfield name="username" key="struts.myssh.name" size="20" /> 22 <s:password name="password" key="struts.myssh.password" size="20" /> 23 <s:submit key="struts.myssh.login" /> 24 </s:form> 25 </s:if> 26 <s:else> 27 ${session.username} 28 </s:else> 29 </body> 30 </html>
通过<s:if></if>标签判断session.username(用户名)是否存在，如果存在显示标签内的模块内容，如果不存在，显示<s:else></s:else>标签内的模块内容。