From WebSecurityConfigurerAdapter.init(WebSecurity)
:
public void init(final WebSecurity web) throws Exception {
final HttpSecurity http = getHttp();
web
.addSecurityFilterChainBuilder(http)
.postBuildAction(new Runnable() {
public void run() {
FilterSecurityInterceptor securityInterceptor = http.getSharedObject(FilterSecurityInterceptor.class);