struts action list前端显示 NullPointerException

[younerest]

最近在学习struts2，遇到了个问题，下面是一个action


public class CustormerListAction extends ActionSupport{
private List<String>grouplist=new ArrayList<String>();
private group groupimpl;
private customer customerimpl;
........省略get set.......
@Override
public String execute() throws Exception {
String userid=(String)session.get("userid");
List<Groupmessage>gmsglist=groupimpl.findByOwnerid(Integer.parseInt(userid));
String hql2="from Customer customer where ";
int count=0;
for(Groupmessage g:gmsglist)
{
if(count==0)
{
hql2=hql2+"customer.groupmsg.groupId="+g.getGroupId();
}else
{
hql2=hql2+" or customer.groupmsg.groupId="+g.getGroupId();
}
count++;
}
List<Customer> customerlist=customerimpl.findCustomerBySql(hql2);
HttpSession session = request.getSession();
session.setAttribute("refreshaction","CustormerListAction.action");
session.setAttribute("noticemessage","正在导出用户列表，请稍后");
Thread.sleep(5000); request.setAttribute("custormerlist",customerlist);
return SUCCESS;
}

该action主要要实现的事从数据库里面取出customer放入custormerlist，然后在jsp页面显示，正常情况下是没有问题，但当我加入红色的这行，让程序sleep5秒的时候，就会报下面这个提示：
严重: Servlet.service() for servlet default threw exception
java.lang.NullPointerException
at org.apache.catalina.connector.Request.setAttribute(Request.java:1424)
at org.apache.catalina.connector.RequestFacade.setAttribute(RequestFacade.java:503)
at javax.servlet.ServletRequestWrapper.setAttribute(ServletRequestWrapper.java:284)
at com.text.Action.CustormerListAction.execute(CustormerListAction.java:58)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:404)
at com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:267)
at org.apache.struts2.interceptor.BackgroundProcess$1.run(BackgroundProcess.java:56)
at java.lang.Thread.run(Thread.java:619)
请大侠们看下是什么问题

[夜空中苦逼的程序员]

虽不知，但觉厉~~

[dengyulong]

at com.text.Action.CustormerListAction.execute(CustormerListAction.java:58) 58行是哪一行？ 是不是session失效了

[younerest]

[Quote=引用 2 楼 的回复:]
at com.text.Action.CustormerListAction.execute(CustormerListAction.java:58) 58行是哪一行？ 是不是session失效了
[/Quote]

58行是这一行
request.setAttribute("custormerlist",customerlist);

[五哥]

Thread.sleep(5000);
//到这里好像request已经为null了
System.out.println("request == " + request) ;//看看打印的结果

request.setAttribute("custormerlist",customerlist);
return SUCCESS;

[不关橙猫猫事的哦]

你的request哪来的？ServletActionContext.getRequest() ??

[younerest]

谢谢各位了，换了另一种方法解决了，用struts直接传值过去，不用request了。