Shiro 的 ShiroFilterFactoryBean 在设置 ChainDefinitionMap 最多 12 条的限制如何破？

先上代码：

ShiroFilterFactoryBean  shiroFilterFactoryBean = new  ShiroFilterFactoryBean();

shiroFilterFactoryBean.setSecurityManager(securityManager);

shiroFilterFactoryBean.setLoginUrl("/login/login");
shiroFilterFactoryBean.setSuccessUrl("/index");
shiroFilterFactoryBean.setUnauthorizedUrl("/403");

Map<String, String> filterChainDefinitionMap = new  HashMap<String, String>();
filterChainDefinitionMap.put("/favicon.ico", "anon");
filterChainDefinitionMap.put("/css/**", "anon");
filterChainDefinitionMap.put("/js/**", "anon");
filterChainDefinitionMap.put("/lib/**", "anon");
filterChainDefinitionMap.put("/mock/**", "anon");
filterChainDefinitionMap.put("/images/**", "anon");
filterChainDefinitionMap.put("/captcha/**", "anon");
filterChainDefinitionMap.put("/login/**", "anon");
filterChainDefinitionMap.put("/register/**", "anon");
filterChainDefinitionMap.put("/plugin/**" , "anon");
filterChainDefinitionMap.put("/logout", "logout");
filterChainDefinitionMap.put("/**", "authc");
shiroFilterFactoryBean.setFilterChainDefinitionMap(filterChainDefinitionMap);
return  shiroFilterFactoryBean;

在 filterChainDefinitionMap 下面最多可以配置 12 条验证规则，如果我再添加一条就会出问题，比如 images 下的图片也将会被要求验证才能访问。

现在请问下这种情况有没有什么办法可以解决？