How can we disable a guice filter at runtime or on application startup?

Question

I have multiple filters defined in my Google guice application. But is there a way I can disable certain filters at runtime or on application startup?

  bind(MyService.class).to(MyServiceImpl.class);
  filter("/*").through(MyFilter.class);
  filter("/myservlet").through(MyServletFilter.class);

In the code above there are 2 filters registered; what I want is to enable/disable these filters or modify the filter chain based up some configuration like:

filters.to.disable=my.app.package.MyFilter,my.app.package.MyServletFilter

Let me know if you have any inputs or suggestions. Thanks !

Answer 1

I believe there is no built-in method to do it, but you could create your own utility which would accept filters.to.disable value and use it to check if the filter is enabled. E.g.:

class FilterDisabler {
    private final Set<String> disabledFilterClasses;

    @Inject
    FilterDisabler(Set<String> disabledFilterClasses) {
        this.disabledFilterClasses = disabledFilterClasses;
    }

    boolean isDisabled(Class<?> clz) {
        return disabledFilterClasses.contains(clz.getName());
    }
}

class MyFilter implements Filter {

    private final FilterDisabler filterDisabler;

    @Inject
    MyFilter(FilterDisabler filterDisabler) {
        this.filterDisabler = filterDisabler;
    }

    @Override
    public void doFilter(
        ServletRequest request,
        ServletResponse response,
        FilterChain chain
    ) throws IOException, ServletException {
        if (filterDisabler.isDisabled(this.getClass())) {
            chain.doFilter(request, response);
            return;
        }
        // filter logic
    }
}