Servlet-- request forwarding / redirection

One or two jump method difference:

classification	Request forwarding	Redirect
Object ownership	request	response
url	/ Connection name	/ Application name / connection name
Jump range	This application	This application or external
The browser address	constant	Variety
Transfer request	Transfer request	Re-request
speed	fast	slow

 Second, the request is forwarded:

　　（1）request.getRequestDispatcher("/BServlet").forward(request, response);

　　（2）request.getRequestDispatcher("/BServlet").includ(request, response);

　　　　// If a forward jump back response of the output is not performed;

　　　　// and use include to jump, then include the servlet executed, and then returns to the original output servlet execution response (if any);

　　important point:

　　(1) must be a jump in the current application;

　　(2) url must be the shortest path to the resource;

　　　　// For the servlet is urlparrent; for html html page name is .html

　　Address unchanged (3) forward; is a request;

 Third, the redirection:

　　// response code 302: indicates redirection;

　　1. redirected created:

　　　　(1) setting the status code and the response header;

 　　　　       response.setStatus(302);

　　　　        response.setHeader("Location", "http://www.baidu.com");

　　　　( 2 ) the sendRedirect () Method:

　　　　　　response.sendRedirect("http://www.baidu.com");

　　　　　　　//response.sendRedirect("/hello/BServlet");

　　2. Redirect Summary:

　　(1) is twice redirected request;

　　(2) redirect url is not limited to this application, it may be other applications;

　　(3 do not use the post) redirection response.getWriter () or response.getOutputStream () output data;