java - Servlet: Cannot forward after response has been committed

Question

I'm working on servlet page that renders content based on geo-location, and I want to use both sendRedirect and forward together; e.g; you browse example.com/aPage.jsp from France; first I want the servlet to redirect you to example.com/fr/aPage.jsp and then forward you to the resources page.

This is what I have in my servlet:

public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  ....
  response.sendRedirect(REDIRECT_URL_BASED_ON_GEO);
  // after redirect forward the resources page
  RequestDispatcher view = request.getRequestDispatcher(RESOURCES_PAGE);
  view.forward(request, response);
  ...
}

But I get:

java.lang.IllegalStateException: Cannot forward after response has been committed

I know the error appears because I can't use both sendRedirect and forward one after another, but I don't know how to achieve what I want (as described above) without this.

any help?

Answer 1

 response.sendRedirect(REDIRECT_URL_BASED_ON_GEO);
  // after redirect forward the resources page

After that line , Your response start writing to clinet.

And you are trying to add additional data to it.

The server has already finished writing the response header and is writing the body of the content, and which point you are trying to write more to the header - of course it cant rewind.

So,Thumb rule while dealing with servlet is

Finish your logic before redirect or forward add return statement.So execution ends there .