config/src/main/java/org/springframework/security/config/http/HttpConfigurationBuilder.java
private void createServletApiFilter(BeanReference authenticationManager) {
		final String ATT_SERVLET_API_PROVISION = "servlet-api-provision";
		final String DEF_SERVLET_API_PROVISION = "true";

		String provideServletApi = httpElt.getAttribute(ATT_SERVLET_API_PROVISION);
		if (!StringUtils.hasText(provideServletApi)) {
			provideServletApi = DEF_SERVLET_API_PROVISION;
		}

		if ("true".equals(provideServletApi)) {
			servApiFilter = GrantedAuthorityDefaultsParserUtils.registerWithDefaultRolePrefix(pc, SecurityContextHolderAwareRequestFilterBeanFactory.class);
			servApiFilter.getPropertyValues().add("authenticationManager",
					authenticationManager);
		}
	}
private void createServletApiFilter(BeanReference authenticationManager) {
		final String ATT_SERVLET_API_PROVISION = "servlet-api-provision";
		final String DEF_SERVLET_API_PROVISION = "true";

		String provideServletApi = httpElt.getAttribute(ATT_SERVLET_API_PROVISION);
		if (!StringUtils.hasText(provideServletApi)) {
			provideServletApi = DEF_SERVLET_API_PROVISION;
		}

		if ("true".equals(provideServletApi)) {
			servApiFilter = GrantedAuthorityDefaultsParserUtils.registerWithDefaultRolePrefix(pc, SecurityContextHolderAwareRequestFilterBeanFactory.class);
			servApiFilter.getPropertyValues().add("authenticationManager",
					authenticationManager);
		}
	}
Adds the servlet-api integration filter if required