Difference between RequestDispatcher and sendRedirect method .

Question

Hello What is the basic difference between RequestDispatcher and sendRedirect method ?

Vikas Mishra · Answer

Hi.. Ervin for the difference you may follow the following link....... http://www.roseindia.net/help/java/s/forward-vs-redirect.shtml I sure that this help in understanding the basic difference ........ thanks........

Prabhu Raja · Answer

Hi RequestDispatcher forward method pass the control of the request to another servlet or jsp without telling anything about the request dispatch to the client browser. Therefore client browser don't know whether the returned resource is from an another servlet/jsp or not. sendRedirect method stop further processing of the request and send http status code 301 and URL of the location to be redirected to the client browser in the response header. Server does not have control of this request after sending the redirect related HTTP header to the client browser. Client browser sees http status 301 and then it know it should send a new request to the url in Location http header which is set by server. and Client browser sends a new request to the new URL and it will be processed by the server as another normal request. Therefore request dispatch happens completely in the server side. But sendRedirect is handle through the client browser. For more reference : Click Here

Satyapriya Nayak · Answer

Hi Ervin Normal 0 response.sendRedirect(): This is complete new request to browser. Request is not maintained so data stored in request object not available to redirect page. You have to store data in session to get in the redirect jsp. You can pass data like response.sendRedirect(/abc.jsp?name=satya). Then in the abc.jsp you have to get name using request.getParameter(name); This is fresh call to server. For example .. you forwarded from /login to login.jsp in the browser you can see /login.jsp.... requestDispatcher.forward() : This not new request. Just transfer the content to forwarded jsp. You can store data in request and able to get in redirect jsp. For example .. you forwarded from /login to login.jsp in the browser you can see /login .... Disadvantage - browser refresh call to /loginj again. may be duplicate data submit. Also refer the below link http://www.roseindia.net/help/java/s/forward-vs-redirect.shtml