接口 HandlerMapping
- 所有已知实现类:
AbstractHandlerMapping,AbstractMapBasedHandlerMapping,DefaultAnnotationHandlerMapping,ParameterHandlerMapping,PortletModeHandlerMapping,PortletModeParameterHandlerMapping
public interface HandlerMapping
Interface to be implemented by objects that define a mapping between requests and handler objects.This class can be implemented by application developers, although this is not necessary, as
PortletModeHandlerMapping,ParameterHandlerMappingandPortletModeParameterHandlerMappingare included in the framework. The first is the default if no HandlerMapping bean is registered in the portlet application context.HandlerMapping implementations can support mapped interceptors but do not have to. A handler will always be wrapped in a
HandlerExecutionChaininstance, optionally accompanied by someHandlerInterceptorinstances. The DispatcherPortlet will first call each HandlerInterceptor'spreHandlemethod in the given order, finally invoking the handler itself if allpreHandlemethods have returnedtrue.The ability to parameterize this mapping is a powerful and unusual capability of this Portlet MVC framework. For example, it is possible to write a custom mapping based on session state, cookie state or many other variables. No other MVC framework seems to be equally flexible.
Note: Implementations can implement the
Orderedinterface to be able to specify a sorting order and thus a priority for getting applied by DispatcherPortlet. Non-Ordered instances get treated as lowest priority.- 作者:
- John A. Lewis, Juergen Hoeller
- 另请参阅:
Ordered,AbstractHandlerMapping,PortletModeHandlerMapping,ParameterHandlerMapping,PortletModeParameterHandlerMapping
方法概要
所有方法 实例方法 抽象方法 修饰符和类型 方法 说明 HandlerExecutionChaingetHandler(PortletRequest request)Return a handler and any interceptors for this request.
方法详细资料
getHandler
HandlerExecutionChain getHandler(PortletRequest request) throws Exception
Return a handler and any interceptors for this request. The choice may be made on portlet mode, session state, or any factor the implementing class chooses.The returned HandlerExecutionChain contains a handler Object, rather than even a tag interface, so that handlers are not constrained in any way. For example, a HandlerAdapter could be written to allow another framework's handler objects to be used.
Returns
nullif no match was found. This is not an error. The DispatcherPortlet will query all registered HandlerMapping beans to find a match, and only decide there is an error if none can find a handler.- 参数:
request- current portlet request- 返回:
- a HandlerExecutionChain instance containing handler object and any interceptors, or null if no mapping found
- 抛出:
Exception- if there is an internal error