jsp页面request.getAttribute("employeeList") 为null

Question

search.jsp代码
<% List employees =(List)request.getAttribute("employeeList"); %>
servlet代码
List employees = dao.findAll();
//结果传到jsp
request.setAttribute("employeeList", employees);
List list =(List)request.getAttribute("employeeList");
// System.out.println(list.size());
response.sendRedirect("search.jsp");

Answer 1

知道原因了，应该用 request.getRequestDispatcher("search.jsp").forward(request,response);

request.getRequestDispatcher()是请求转发，前后页面共享一个request ;
response.sendRedirect()是重新定向，前后页面不是一个request。