jfinal2.1+jsp,前台取值报错?报错

@JFinal 你好，想跟你请教个问题：我用jfinal2.1+jsp写程序，后台语句是：

public void useradmin() {  
  List<Users> list = Users.dao.find("select a.*,b.role_name,c.org_name from users a left join role b on a.role = b.role_id left join orgs c on a.org_id = c.org_id ");
  setAttr("userList", list);  
render("/system/useradmin.jsp");

}

前台语句是：

<c:forEach items="${userList}" var="user">
<tr >

<td style="text-align: center;">${user.user_id}
　</td>
<td style="text-align: center;">
　</td>
<td style="text-align: center;">　</td>
<td style="text-align: center;"></td>
<td style="text-align: center;"> 
  　
</td>

</tr> 
</c:forEach>

users的Model

@SuppressWarnings("serial")
public class Users extends BaseUsers<Users> {
public static final Users dao = new Users();
}

报错：

Caused by: javax.el.PropertyNotFoundException: Property 'user_id' not found on type com.post.common.model.Users
at javax.el.BeanELResolver$BeanProperties.get(BeanELResolver.java:238)
at javax.el.BeanELResolver$BeanProperties.access$400(BeanELResolver.java:191)
at javax.el.BeanELResolver.property(BeanELResolver.java:324)
at javax.el.BeanELResolver.getValue(BeanELResolver.java:81)
at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:54)
at org.apache.el.parser.AstValue.getValue(AstValue.java:123)
at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:182)
at org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate(PageContextImpl.java:897)
at org.apache.jsp.system.useradmin_jsp._jspx_meth_c_005fforEach_005f0(useradmin_jsp.java:235)
at org.apache.jsp.system.useradmin_jsp._jspService(useradmin_jsp.java:182)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:723)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:388)
... 27 more

我很奇怪，com.post.common.model.Users对应的表users有user_id这个字段的，为什么提示

Caused by: javax.el.PropertyNotFoundException: Property 'user_id' not found on type com.post.common.model.Users