FilterContext crash course

MyResponseFilter.java

final class MyResponseFilter
    implements ResponseFilter
{
    @Override
    public FilterContext filter( FilterContext ctx )
        throws FilterException
    {
        if ( somethingMagicHappens )
        {
            RequestBuilder authRequestBuilder = new RequestBuilder( "POST" )
                                                        .setUrl( "http://my.rest.server/" );

            for ( Cookie cookie : cookiesRegistry.get( "XXX" ) )
            {
                authRequestBuilder.addCookie( cookie );
            }

            for ( Parameter parameter : storedParams.getParameters() )
            {
                authRequestBuilder.addParameter( parameter.getName(), parameter.getValue() );
            }

            return new FilterContext.FilterContextBuilder()
                                .request( authRequestBuilder.build() )
                                .asyncHandler( ctx.getAsyncHandler() )
                                .build();
        }

        return ctx;

    }

}