Acegi里一个很奇怪的方法调用

看Acegi源码时,发现这么一段有些奇怪的代码.

 protected Filter[] obtainAllDefinedFilters() {
        Iterator cads = this.filterInvocationDefinitionSource.getConfigAttributeDefinitions();
        Set list = new LinkedHashSet();

        while (cads.hasNext()) {
            ConfigAttributeDefinition attribDef = (ConfigAttributeDefinition) cads.next();
            Filter[] filters = obtainAllDefinedFilters(attribDef);

            for (int i = 0; i < filters.length; i++) {
                list.add(filters[i]);
            }
        }

        return (Filter[]) list.toArray(new Filter[0]);
 }

红色的代码为什么不直写成: return obtainAllDefinedFilters(attribDef);呢? 毕竟 obtainAllDefinedFilters本身就是返回一个Filter数组,为什么那个方法里还有再重复的加到一个List中,再把list转为数组呢？　

是Acegi开发小组粗心的过?还是有意为之?

 

下面是红色代码调用的那个方法:

 

private Filter[] obtainAllDefinedFilters(ConfigAttributeDefinition configAttributeDefinition) {
        List list = new Vector();
        Iterator attributes = configAttributeDefinition.getConfigAttributes();

        while (attributes.hasNext()) {
            ConfigAttribute attr = (ConfigAttribute) attributes.next();
            String filterName = attr.getAttribute();

            if (filterName == null) {
                throw new IllegalArgumentException("Configuration attribute: '" + attr
                    + "' returned null to the getAttribute() method, which is invalid when used with FilterChainProxy");
            }

            if (!filterName.equals(TOKEN_NONE)) {
                list.add(this.applicationContext.getBean(filterName, Filter.class));
            }
        }

        return (Filter[]) list.toArray(new Filter[list.size()]);
    }