一个关于ArrayList的问题，求大虾帮我看看错在那里？
ArrayList   list=(ArrayList)request.getAttribute( "list ");
String   error=(String)request.getAttribute( "error ");
if(list==null)
{  
  if(error==null)
  {
        list=bean.getList( "select   *   from   sp ",1);
  }
}

------解决方案--------------------
Object obj1 = request.getAttribute( "list ");
Object obj2 = request.getAttribute( "error ");
List list = null;
String error = null;
if(obj1 == null){
if(obj2 == null){
list=bean.getList( "select * from sp ",1);
}else{
error=(String)obj2;
}
}else{
list=(List)obj1;
}