struts2中从页面传到action然后再传到页面数据怎么显示不出来？

大家帮忙帮我看看吧。谢谢
首先是一个recSuc.jsp页面
<center> <font color="red">用户详细信息</font>
    <table cellpadding="0" cellspacing="0" align="center" border="0" width="80%">
     <thead>
       <tr align="center">
          <th>账号</th>
          <th>姓名</th>
          <th>口令</th>
          <th>性别</th>
          <th>年龄</th>
          <th>爱好</th>  
          <th>操作</th>
        </tr>
     </thead>    <tbody>
          <s:iterator id="mylist" value="#request.list">
         <tr align="center">
          <td><s:property value="#mylist.userId"/></td>
          <td><s:property value="#mylist.userName"/></td>
          <td><s:property value="#mylist.userPwd"/></td>
          <td><s:property value="#mylist.userSex"/></td>
          <td><s:property value="#mylist.userAge"/></td>
          <td><s:property value="#mylist.userFav"/></td>
          <td>
           <!-- 
          <a href="update.jsp">修改</a>
           -->
      
          <a href='<s:url action="edit"><s:param name="userId" value="#mylist.userId"></s:param></s:url>'>修改</a>          <a href='<s:url action="delete"><s:param name="userId" value="userId"></s:param></s:url>'>删除</a>
          <a href='<s:url action="insert"><s:param name="userId" value="userId"></s:param></s:url>'>添加</a>
             </td>
         </tr>
        </s:iterator>当我点击修改操作时，传到action中，执行方面edit，
private static final long serialVersionUID = 1L;
    private User user;
    private List<User> list;
private String userId;
public List<User> getList() {
return list;
}
public void setList(List<User> list) {
this.list = list;
}
public String getUserId() {
return userId;
}
public void setUserId(String userId) {
this.userId = userId;
}
public User getUser() {
return user;
}
public void setUser(User user) {
this.user = user;
} private UserService service;
public UserService getService() {
   return service;
}
public void setService(UserService service) {
   this.service = service;
}

@SuppressWarnings("unchecked")
public String login() throws Exception 
{
User u=null;
u=this.service.login(user.getUserId(),user.getUserPwd());
System.out.println("u ="+u);
if(u!=null){
Map request = (Map)ActionContext.getContext().get("request");
 list = this.service.findAll();
if(list!=null){
request.put("list", list);
return SUCCESS;
}
}
return INPUT;
}

public String Edit(){
user=(User)this.service.edit(Integer.parseInt(userId));
return SUCCESS;
}
public String update(){
User u=new User();
u.setUserId(Integer.parseInt(userId));
u.setUserName(user.getUserName());
u.setUserPwd(user.getUserPwd());
u.setUserSex(user.getUserSex());
u.setUserAge(user.getUserAge());
u.setUserFav(user.getUserFav());
this.service.update(u);
return SUCCESS;
}

}
执行完edit方法后，进入update.jsp.在执行update方法。
update.jsp代码如下
<center>
        <font color="red">用户信息修改</font>
       <s:form action="update" method="post">
        <s:textfield name="user.userName" label="姓名"/>
        <s:textfield name="user.userPwd" label="口号" />
        <s:textfield name="user.userSex" label="性别" />
        <s:textfield name="user.userAge" label="年龄" />
        <s:textfield name="user.userFav" label="爱好"/>
        <s:submit></s:submit>
       </s:form>
  </center>
在跳进action执行update.最后在跳进recSuc.jsp页面。但是问题来了，当进入update.jsp页面时，数据显示不出来。怎么回事呀！大家帮帮忙呀1