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

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search.jsp代码

<% List<Employee> employees =(List<Employee>)request.getAttribute("employeeList"); %>

servlet代码

public void service(HttpServletRequest request, HttpServletResponse response) throws IOException {response.setContentType("text/html;charset=utf-8");PrintWriter pw = response.getWriter();try {EmployeeDAO dao = (EmployeeDAO) Factory.getInstance("EmployeeDAO");List<Employee> employees = dao.findAll();//结果传到jsprequest.setAttribute("employeeList", employees);List<Employee> list =(List<Employee>)request.getAttribute("employeeList");//System.out.println(list.size());//response.sendRedirect("search.jsp");request.getRequestDispatcher("search.jsp").forward(request,response);} catch (Exception e1) {e1.printStackTrace();}}

问题的原因是，之前采用了sendRedirect进行重定向，而应该采用
request.getRequestDispatcher("search.jsp").forward(request,response);
查了一下这两者的区别：
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

转自：http://www.cnblogs.com/phpzxh/archive/2010/02/01/1661137.html

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