如果缺少配置，则重定向到安装程序

Question

I'm trying to create a basic java web app using servlet 3.0. Now, my application needs to run through a basic setup page/form so it knows where to store config files etc. What would be a good way to implement this?

I was thinking of a filter, but since i cant do a redirect, that seems like the wrong way.

Suggestions?

Answer 1

Seems to me that a Filter would be a great approach to what you're trying to accomplish:

@WebFilter
public class ConfigFilter implements Filter {
    @Inject
    private SessionBean session;

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        String requestURI = ((HttpServletRequest) request).getRequestURI();
        if(!session.hasConfig() && !requestURI.startsWith("/configWizard.xhtml")) {
            ((HttpServletResponse) response).sendRedirect("/configWizard.xhtml");
        }
        else {
            chain.doFilter(request, response);
        }
    }

    @Override
    public void destroy() {
    }

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    }
}