Question

I’m migrate application to the new JavaEE6 standard. And annotation is very easy to use when creating new filters. I only need to add a @WebFilter annotation to my POJO classes and it works well.

What confused me is: all filters with the annotation would be automatically loaded by the container. This is not desired sometimes. I may create a set of filters and different webapp would choose to use only subset of these filters. So the question I have: is there an easy way to enable / disable filters based on different deployment, while still allow me to use the simple WebFilter annotation for each filter class?

I found this article when searching on this top:
Dynamically registering WebFilter with Java EE 6

But this article seems to suggest not using annotations on each filter class, and load them via a ServletContextListener directly referencing each filter class. It doesn’t seem to be an optimal solution.

Thank you,

Answer 1

That’s not possible.

Your best bet is to extend the filters with a check on some web.xml context param, or a VM argument, or an environment variable which indicates that the filter should not be used.

E.g.

@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
    if ("true".equals(System.getProperty("com.example.DISABLE_FILTER"))) {
        chain.doFilter(request, response);
        return;
    }

    // Original filter code here.
}

which can be disabled by supplying VM argument -Dcom.example.DISABLE_FILTER=true.