How to create my own filter with Spring MVC?

Question

I use Spring MVC (4.0.1) as a backend for rest services and angularjs as frontend.

every request to my server backend has a http-header with a session id

I c

Answer 1

Below is the filter to perform the logic you have mentioned

@WebFilter("/*")
public class AuthTokenFilter implements Filter {

    @Override
    public void destroy() {
        // ...
    }

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

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        String xHeader = ((HttpServletRequest)request).getHeader("X-Auth-Token");
        if(getPermission(xHeader)) {
            chain.doFilter(request, response);
        } else {
            request.getRequestDispatcher("401.html").forward(request, response);
        }
    }
}

And you got it right, the spring config should be following.

public class MyWebInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {
    @Override
    protected Filter[] getServletFilters() {
        return new Filter[]{new AuthTokenFilter()};
    }
}