Question

I’m trying to create a simulation for our web Portal and need to add custom HTTP headers. I am to assume the user has already been authenticated and these headers are just for storing user information (ie, “test-header: role=user; oem=blahblah; id=123;”).

I’ve setup a filter to extract the header information but I can’t find a way to inject the header information. They don’t want it to be stored in cookies and maybe they will want to setup a global filter to include the headers on every page; is it possible to do something like this with the filter interface or through any other methods?

Answer 1

Maybe you can store that information in the session:

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * @author rodrigoap
 * 
 */
public class UserInfoFilter implements Filter {

    /**
     * @see javax.servlet.Filter#destroy()
     */
    public void destroy() {
        // TODO
    }

    /**
     * @see javax.servlet.Filter#doFilter(javax.servlet.ServletRequest,
     *      javax.servlet.ServletResponse, javax.servlet.FilterChain)
     */
    public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain filterChain) throws IOException, ServletException {
        if (!(request instanceof HttpServletRequest))
            throw new ServletException("Can only process HttpServletRequest");
        if (!(response instanceof HttpServletResponse))
            throw new ServletException("Can only process HttpServletResponse");
        HttpServletRequest httpRequest = (HttpServletRequest) request;
        HttpServletResponse httpResponse = (HttpServletResponse) response;

        httpRequest.getSession().setAttribute("role", "user");
        httpRequest.getSession().setAttribute("id", "123");
                filterChain.doFilter(request, response);
    }

    /**
     * @see javax.servlet.Filter#init(javax.servlet.FilterConfig)
     */
    public void init(FilterConfig filterConfig) throws ServletException {
        // TODO
    }

}