Workaround for relative location headers via sendRedirect() for Wildfly and other containers

RelativeRedirectsFilter.java

@WebFilter(urlPatterns = "/*")
public class RelativeRedirectsFilter implements Filter {

  @Override
  public void doFilter( ServletRequest request, ServletResponse response, FilterChain chain )
    throws IOException, ServletException {

    chain.doFilter( request, new RelativeRedirectResponse( (HttpServletResponse) response ) );

  }

  private static class RelativeRedirectResponse extends HttpServletResponseWrapper {

    public RelativeRedirectResponse( HttpServletResponse response ) {
      super( response );
    }

    @Override
    public void sendRedirect( String location ) throws IOException {

      if( location.startsWith( "/" ) ) {
        setStatus( 302 );
        setHeader( "Location", location );
      }
      else {
        super.sendRedirect( location );
      }

    }
  }

}