Servlet之间的跳转

转向(Forward)

  转向是通过RequestDispatcher对象的forward(HttpServletRequest req, HttpServletResponse res)方法来实现的。RequestDispatcher可以通过HttpServletRequest的getRequestDispatcher()方法获得。
  getRequestDispatcher()方法的参数必须以"/"开始，"/"表示本Web应用程序的根目录

 

public class ForwardServlet extends HttpServlet{
 
   public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException{
       
       String destination = request.getParameter("destination");
       
       if("file".equals(destination)){
          RequestDispatcher d = request.getRequestDispatcher("/WEB-INF/web.xml");
          d.forward(request,response);
       }
       else if("jsp".equals(destination)){
          request.setAttribute("date",new Date());       //传递一个Date对象给JSP页面
          RequestDispatcher d = request.getRequestDispatcher("/forward.jsp");
          d.forward(request,response);
       }
       else{
          response.setCharacterEncoding("UTF-8");
          response.getWriter().println("缺少参数。用法："+request.getRequestURL() + "?destination=jsp或者file");
       }
   }
}