Spring Security内置过滤器的维护方法

CopyFilterOrderRegistration filterOrderRegistration = new CopyFilterOrderRegistration();
        // 获取内置过滤器  此方法并未提供
        Map<String, Integer> filterToOrder = filterOrderRegistration.getFilterToOrder();
        TreeMap<Integer, String> orderToFilter = new TreeMap<>();
        filterToOrder.forEach((name, order) -> orderToFilter.put(order,name));
        orderToFilter.forEach((order,name) -> System.out.println(" 顺序：" + order+" 类名：" + name ));

 void put(Class<? extends Filter> filter, int position) {
  String className = filter.getName();
        // 如果这个类已经注册就忽略
  if (this.filterToOrder.containsKey(className)) {
   return;
  }
        // 如果没有注册就注册顺序。
  this.filterToOrder.put(className, position);
 }

  Integer getOrder(Class<?> clazz) {
        // 如果类Class 或者 父类Class 名为空就返回null
        while (clazz != null) {
            Integer result = this.filterToOrder.get(clazz.getName());
            // 如果获取到顺序值就返回
            if (result != null) {
                return result;
            }
            // 否则尝试去获取父类的顺序值
            clazz = clazz.getSuperclass();
        }
        return null;
    }

 private HttpSecurity addFilterAtOffsetOf(Filter filter, int offset, Class<? extends Filter> registeredFilter) {
        // 首先会根据registeredFilter的顺序和偏移值来计算filter的
  int order = this.filterOrders.getOrder(registeredFilter) + offset;
        // filter添加到集合中待排序
  this.filters.add(new OrderedFilter(filter, order));
        // filter注册到 FilterOrderRegistration
  this.filterOrders.put(filter.getClass(), order);
  return this;
 }

 @Override
 public HttpSecurity addFilterAfter(Filter filter, Class<? extends Filter> afterFilter) {
  return addFilterAtOffsetOf(filter, 1, afterFilter);
 }

 @Override
 public HttpSecurity addFilter(Filter filter) {
  Integer order = this.filterOrders.getOrder(filter.getClass());
  if (order == null) {
   throw new IllegalArgumentException("The Filter class " + filter.getClass().getName()
     + " does not have a registered order and cannot be added without a specified order. Consider using addFilterBefore or addFilterAfter instead.");
  }
  this.filters.add(new OrderedFilter(filter, order));
  return this;
 }

// filters
private List<OrderedFilter> filters = new ArrayList<>(); 
//排序
this.filters.sort(OrderComparator.INSTANCE);