org.springframework.web.servlet.handler
Class AbstractHandlerMapping

java.lang.Object
  org.springframework.context.support.ApplicationObjectSupport
      org.springframework.web.context.support.WebApplicationObjectSupport
          org.springframework.web.servlet.handler.AbstractHandlerMapping

All Implemented Interfaces:

ApplicationContextAware, Ordered, ServletContextAware, HandlerMapping

Direct Known Subclasses:

AbstractUrlHandlerMapping

public abstract class AbstractHandlerMapping
extends WebApplicationObjectSupport
implements HandlerMapping, Ordered

Abstract base class for HandlerMapping implementations. Supports ordering, a default handler, and handler interceptors.

Note: This base class does not support exposure of the HandlerMapping.PATH_WITHIN_HANDLER_MAPPING_ATTRIBUTE. Support for this attribute is up to concrete subclasses, typically based on request URL mappings.

Since:

07.04.2003

Author:

Juergen Hoeller

See Also:

getHandlerInternal(javax.servlet.http.HttpServletRequest), setDefaultHandler(java.lang.Object), setInterceptors(java.lang.Object[]), HandlerInterceptor

Field Summary

Fields inherited from class org.springframework.context.support.ApplicationObjectSupport

logger

Fields inherited from interface org.springframework.web.servlet.HandlerMapping

PATH_WITHIN_HANDLER_MAPPING_ATTRIBUTE

Fields inherited from interface org.springframework.core.Ordered

HIGHEST_PRECEDENCE, LOWEST_PRECEDENCE

Constructor Summary

AbstractHandlerMapping()

Method Summary

protected HandlerInterceptor	adaptInterceptor(Object interceptor) Adapt the given interceptor object to the HandlerInterceptor interface.
protected void	extendInterceptors(List interceptors) Extension hook that subclasses can override to register additional interceptors, given the configured interceptors (see setInterceptors(java.lang.Object[])).
protected HandlerInterceptor[]	getAdaptedInterceptors() Return the adapted interceptors as HandlerInterceptor array.
Object	getDefaultHandler() Return the default handler for this handler mapping, or null if none.
HandlerExecutionChain	getHandler(HttpServletRequest request) Look up a handler for the given request, falling back to the default handler if no specific one is found.
protected HandlerExecutionChain	getHandlerExecutionChain(Object handler, HttpServletRequest request) Build a HandlerExecutionChain for the given handler, including applicable interceptors.
protected abstract Object	getHandlerInternal(HttpServletRequest request) Look up a handler for the given request, returning null if no specific one is found.
int	getOrder() Return the order value of this object, with a higher value meaning greater in terms of sorting.
protected void	initApplicationContext() Initializes the interceptors.
protected void	initInterceptors() Initialize the specified interceptors, adapting them where necessary.
void	setDefaultHandler(Object defaultHandler) Set the default handler for this handler mapping.
void	setInterceptors(Object[] interceptors) Set the interceptors to apply for all handlers mapped by this handler mapping.
void	setOrder(int order) Specify the order value for this HandlerMapping bean.

Methods inherited from class org.springframework.web.context.support.WebApplicationObjectSupport

getServletContext, getTempDir, getWebApplicationContext, initApplicationContext, initServletContext, isContextRequired, setServletContext

Methods inherited from class org.springframework.context.support.ApplicationObjectSupport

getApplicationContext, getMessageSourceAccessor, requiredContextClass, setApplicationContext

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AbstractHandlerMapping

public AbstractHandlerMapping()

Method Detail

setOrder

public final void setOrder(int order)

Specify the order value for this HandlerMapping bean.

Default value is Integer.MAX_VALUE, meaning that it's non-ordered.

See Also:

Ordered.getOrder()

getOrder

public final int getOrder()

Description copied from interface: Ordered

Return the order value of this object, with a higher value meaning greater in terms of sorting.

Normally starting with 0 or 1, with Ordered.LOWEST_PRECEDENCE indicating greatest. Same order values will result in arbitrary positions for the affected objects.

Higher value can be interpreted as lower priority, consequently the first object has highest priority (somewhat analogous to Servlet "load-on-startup" values).

Note that order values below 0 are reserved for framework purposes. Application-specified values should always be 0 or greater, with only framework components (internal or third-party) supposed to use lower values.

Specified by:

getOrder in interface Ordered

Returns:

the order value

See Also:

Ordered.LOWEST_PRECEDENCE

setDefaultHandler

public void setDefaultHandler(Object defaultHandler)

Set the default handler for this handler mapping. This handler will be returned if no specific mapping was found.

Default is null, indicating no default handler.

getDefaultHandler

public Object getDefaultHandler()

Return the default handler for this handler mapping, or null if none.

setInterceptors

public void setInterceptors(Object[] interceptors)

Set the interceptors to apply for all handlers mapped by this handler mapping.

Supported interceptor types are HandlerInterceptor and WebRequestInterceptor.

Parameters:

interceptors - array of handler interceptors, or null if none

See Also:

adaptInterceptor(java.lang.Object), HandlerInterceptor, WebRequestInterceptor

initApplicationContext

protected void initApplicationContext()
                               throws BeansException

Initializes the interceptors.

Overrides:

initApplicationContext in class ApplicationObjectSupport

Throws:

ApplicationContextException - in case of initialization errors

BeansException - if thrown by ApplicationContext methods

See Also:

extendInterceptors(java.util.List), initInterceptors()

extendInterceptors

protected void extendInterceptors(List interceptors)

Extension hook that subclasses can override to register additional interceptors, given the configured interceptors (see setInterceptors(java.lang.Object[])).

Will be invoked before initInterceptors() adapts the specified interceptors into HandlerInterceptor instances.

The default implementation is empty.

Parameters:

interceptors - the configured interceptor List (never null), allowing to add further interceptors before as well as after the existing interceptors

initInterceptors

protected void initInterceptors()

Initialize the specified interceptors, adapting them where necessary.

See Also:

setInterceptors(java.lang.Object[]), adaptInterceptor(java.lang.Object)

adaptInterceptor

protected HandlerInterceptor adaptInterceptor(Object interceptor)

Adapt the given interceptor object to the HandlerInterceptor interface.

Supported interceptor types are HandlerInterceptor and WebRequestInterceptor. Each given WebRequestInterceptor will be wrapped in a WebRequestHandlerInterceptorAdapter. Can be overridden in subclasses.

Parameters:

interceptor - the specified interceptor object

Returns:

the interceptor wrapped as HandlerInterceptor

See Also:

HandlerInterceptor, WebRequestInterceptor, WebRequestHandlerInterceptorAdapter

getAdaptedInterceptors

protected final HandlerInterceptor[] getAdaptedInterceptors()

Return the adapted interceptors as HandlerInterceptor array.

Returns:

the array of HandlerInterceptors, or null if none

getHandler

public final HandlerExecutionChain getHandler(HttpServletRequest request)
                                       throws Exception

Look up a handler for the given request, falling back to the default handler if no specific one is found.

Specified by:

getHandler in interface HandlerMapping

Parameters:

request - current HTTP request

Returns:

the corresponding handler instance, or the default handler

Throws:

Exception - if there is an internal error

See Also:

getHandlerInternal(javax.servlet.http.HttpServletRequest)

getHandlerInternal

protected abstract Object getHandlerInternal(HttpServletRequest request)
                                      throws Exception

Look up a handler for the given request, returning null if no specific one is found. This method is called by getHandler(javax.servlet.http.HttpServletRequest); a null return value will lead to the default handler, if one is set.

Note: This method may also return a pre-built HandlerExecutionChain, combining a handler object with dynamically determined interceptors. Statically specified interceptors will get merged into such an existing chain.

Parameters:

request - current HTTP request

Returns:

the corresponding handler instance, or null if none found

Throws:

Exception - if there is an internal error

getHandlerExecutionChain

protected HandlerExecutionChain getHandlerExecutionChain(Object handler,
                                                         HttpServletRequest request)

Build a HandlerExecutionChain for the given handler, including applicable interceptors.

The default implementation simply builds a standard HandlerExecutionChain with the given handler and this handler mapping's common interceptors. Subclasses may override this in order to extend/rearrange the list of interceptors.

NOTE: The passed-in handler object may be a raw handler or a pre-built HandlerExecutionChain. This method should handle those two cases explicitly, either building a new HandlerExecutionChain or extending the existing chain.

For simply adding an interceptor, consider calling super.getHandlerExecutionChain and invoking HandlerExecutionChain.addInterceptor(org.springframework.web.servlet.HandlerInterceptor) on the returned chain object.

Parameters:

handler - the resolved handler instance (never null)

request - current HTTP request

Returns:

the HandlerExecutionChain (never null)

See Also:

getAdaptedInterceptors()