Question

I found this to achieve this job:

Cache-Control: private The next higher directive is “cache-control:
private”. It instructs proxies in the path not to cache the page. But
it permits browsers to cache the page. Proxies are shared resources
used by multiple users, and this directive tells them not to cache the
response. Browsers, as we have already noted, may still cache the
page.

But how can I add this to request header? These cache issues are relevant with response header. So what should I do to add this parameter to request header?

Thanks.

Answer 1

If you are using Servlets, then you can add / set the required response (not request) HTTP header.

Simple example.

import javax.servlet.ServletException;
import java.io.IOException;

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class SomeServlet extends HttpServlet {

    protected void doGet(HttpServletRequest request, HttpServletResponse response)
                    throws ServletException, IOException {
        // some code here

        response.setHeader("Cache-Control", "private");

        // some code here
    }
}

Or you may use response.addHeader("Cache-Control", "private").

It’s just that when using setHeader(), then if the header had already been set, the new value overwrites the previous one.

See Java EE API here:
void addHeader(String name, String value)
void setHeader(String name, String value)