java.lang.Objectorg.acegisecurity.util.FilterChainProxy

All Implemented Interfaces:

Filter, InitializingBean, ApplicationContextAware

public class FilterChainProxy
extends Object
implements Filter, InitializingBean, ApplicationContextAware

Delegates Filter requests to a list of Spring-managed beans.

通过一系列的由spring托管的beans ，代理过滤请求。
FilterChainProxy 通过在web.xml中定义的FilterToBeanProxy 被加载，FilterChainProxy 将会通过init(FilterConfig), destroy() and doFilter(ServletRequest, ServletResponse, FilterChain)调用，调用每一个在其中定义的过滤器。

The FilterChainProxy is loaded via a standard FilterToBeanProxy declaration in web.xml. FilterChainProxy will then pass init(FilterConfig), destroy() and doFilter(ServletRequest, ServletResponse, FilterChain) invocations through to each Filter defined against FilterChainProxy.

 
    FilterChainProxy  是通过一个标准的FilterInvocationDefinitionSource 来实现配置的，每个可能的FilterChainProxy应该服务的URI模式都必须进入
            第一个搭配的URI模式将会被用来定义处理请求的所有的过滤器，就是说只适配第一组过滤器，后面的其他过滤器将无效。
FilterChainProxy is configured using a standard FilterInvocationDefinitionSource. Each possible URI pattern that FilterChainProxy should service must be entered. The first matching URI pattern located by FilterInvocationDefinitionSource for a given request will be used to define all of the Filters that apply to that request. NB: This means you must put most specific URI patterns at the top of the list, and ensure all Filters that should apply for a given URI pattern are entered against the respective entry. The FilterChainProxy will not iterate the remainder of the URI patterns to locate additional Filters. The FilterInvocationDefinitionSource described the applicable URI pattern to fire the filter chain, followed by a list of configuration attributes. Each configuration attribute's ConfigAttribute.getAttribute() corresponds to a bean name that is available from the application context.

FilterChainProxy respects normal handling of Filters that elect not to call Filter.doFilter(javax.servlet.ServletRequest, javax.servlet.ServletResponse, javax.servlet.FilterChain), in that the remainder of the origial or FilterChainProxy-declared filter chain will not be called.

It is particularly noted the Filter lifecycle mismatch between the servlet container and IoC container. As per FilterToBeanProxy JavaDocs, we recommend you allow the IoC container to manage lifecycle instead of the servlet container. By default the FilterToBeanProxy will never call this class' init(FilterConfig) and destroy() methods, meaning each of the filters defined against FilterInvocationDefinitionSource will not be called. If you do need your filters to be initialized and destroyed, please set the lifecycle initialization parameter against the FilterToBeanProxy to specify servlet container lifecycle management.

If a filter name of TOKEN_NONE is used, this allows specification of a filter pattern which should never cause any filters to fire.