org.springframework.web.servlet.handler

Class AbstractHandlerExceptionResolver

java.lang.Object

org.springframework.web.servlet.handler.AbstractHandlerExceptionResolver

All Implemented Interfaces:

Ordered, HandlerExceptionResolver

Direct Known Subclasses:

AbstractHandlerMethodExceptionResolver, AnnotationMethodHandlerExceptionResolver, DefaultHandlerExceptionResolver, ResponseStatusExceptionResolver, SimpleMappingExceptionResolver

public abstract class AbstractHandlerExceptionResolver
extends java.lang.Object
implements HandlerExceptionResolver, Ordered

Abstract base class for HandlerExceptionResolver implementations.

Provides a set of mapped handlers that the resolver should map to, and the Ordered implementation.

Since:

3.0

Author:

Arjen Poutsma, Juergen Hoeller

Field Summary

Fields

Modifier and Type	Field and Description
private static java.lang.String	HEADER_CACHE_CONTROL
private static java.lang.String	HEADER_EXPIRES
private static java.lang.String	HEADER_PRAGMA
protected Log	logger Logger available to subclasses
private java.lang.Class<?>[]	mappedHandlerClasses
private java.util.Set<?>	mappedHandlers
private int	order
private boolean	preventResponseCaching
private Log	warnLogger

Fields inherited from interface org.springframework.core.Ordered

HIGHEST_PRECEDENCE, LOWEST_PRECEDENCE

Constructor Summary

Constructors

Constructor and Description
AbstractHandlerExceptionResolver()

Method Summary

Modifier and Type	Method and Description
protected java.lang.String	buildLogMessage(java.lang.Exception ex, HttpServletRequest request) Build a log message for the given exception, occurred during processing the given request.
protected abstract ModelAndView	doResolveException(HttpServletRequest request, HttpServletResponse response, java.lang.Object handler, java.lang.Exception ex) Actually resolve the given exception that got thrown during on handler execution, returning a ModelAndView that represents a specific error page if appropriate.
int	getOrder() Return the order value of this object, with a higher value meaning greater in terms of sorting.
protected void	logException(java.lang.Exception ex, HttpServletRequest request) Log the given exception at warn level, provided that warn logging has been activated through the "warnLogCategory" property.
protected void	prepareResponse(java.lang.Exception ex, HttpServletResponse response) Prepare the response for the exceptional case.
protected void	preventCaching(HttpServletResponse response) Prevents the response from being cached, through setting corresponding HTTP headers.
ModelAndView	resolveException(HttpServletRequest request, HttpServletResponse response, java.lang.Object handler, java.lang.Exception ex) Checks whether this resolver is supposed to apply (i.e.
void	setMappedHandlerClasses(java.lang.Class<?>[] mappedHandlerClasses) Specify the set of classes that this exception resolver should apply to.
void	setMappedHandlers(java.util.Set<?> mappedHandlers) Specify the set of handlers that this exception resolver should apply to.
void	setOrder(int order)
void	setPreventResponseCaching(boolean preventResponseCaching) Specify whether to prevent HTTP response caching for any view resolved by this HandlerExceptionResolver.
void	setWarnLogCategory(java.lang.String loggerName) Set the log category for warn logging.
protected boolean	shouldApplyTo(HttpServletRequest request, java.lang.Object handler) Check whether this resolver is supposed to apply to the given handler.

Methods inherited from class java.lang.Object

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

Field Detail

HEADER_PRAGMA

private static final java.lang.String HEADER_PRAGMA

See Also:

Constant Field Values

HEADER_EXPIRES

private static final java.lang.String HEADER_EXPIRES

See Also:

Constant Field Values

HEADER_CACHE_CONTROL

private static final java.lang.String HEADER_CACHE_CONTROL

See Also:

Constant Field Values

logger

protected final Log logger

Logger available to subclasses

order

private int order

mappedHandlers

private java.util.Set<?> mappedHandlers

mappedHandlerClasses

private java.lang.Class<?>[] mappedHandlerClasses

warnLogger

private Log warnLogger

preventResponseCaching

private boolean preventResponseCaching

Constructor Detail

AbstractHandlerExceptionResolver

public AbstractHandlerExceptionResolver()

Method Detail

setOrder

public void setOrder(int order)

getOrder

public 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, with Integer.MAX_VALUE indicating the greatest value. Same order values will result in arbitrary positions for the affected objects.

Higher values can be interpreted as lower priority. As a consequence, the object with the lowest value has highest priority (somewhat analogous to Servlet "load-on-startup" values).

Specified by:

getOrder in interface Ordered

Returns:

the order value

setMappedHandlers

public void setMappedHandlers(java.util.Set<?> mappedHandlers)

Specify the set of handlers that this exception resolver should apply to. The exception mappings and the default error view will only apply to the specified handlers.

If no handlers and handler classes are set, the exception mappings and the default error view will apply to all handlers. This means that a specified default error view will be used as fallback for all exceptions; any further HandlerExceptionResolvers in the chain will be ignored in this case.

setMappedHandlerClasses

public void setMappedHandlerClasses(java.lang.Class<?>[] mappedHandlerClasses)

Specify the set of classes that this exception resolver should apply to. The exception mappings and the default error view will only apply to handlers of the specified type; the specified types may be interfaces and superclasses of handlers as well.

If no handlers and handler classes are set, the exception mappings and the default error view will apply to all handlers. This means that a specified default error view will be used as fallback for all exceptions; any further HandlerExceptionResolvers in the chain will be ignored in this case.

setWarnLogCategory

public void setWarnLogCategory(java.lang.String loggerName)

Set the log category for warn logging. The name will be passed to the underlying logger implementation through Commons Logging, getting interpreted as log category according to the logger's configuration.

Default is no warn logging. Specify this setting to activate warn logging into a specific category. Alternatively, override the logException(java.lang.Exception, HttpServletRequest) method for custom logging.

See Also:

org.apache.commons.logging.LogFactory#getLog(String), org.apache.log4j.Logger#getLogger(String), Logger.getLogger(String)

setPreventResponseCaching

public void setPreventResponseCaching(boolean preventResponseCaching)

Specify whether to prevent HTTP response caching for any view resolved by this HandlerExceptionResolver.

Default is "false". Switch this to "true" in order to automatically generate HTTP response headers that suppress response caching.

resolveException

public ModelAndView resolveException(HttpServletRequest request,
                                     HttpServletResponse response,
                                     java.lang.Object handler,
                                     java.lang.Exception ex)

Checks whether this resolver is supposed to apply (i.e. the handler matches in case of "mappedHandlers" having been specified), then delegates to the doResolveException(HttpServletRequest, HttpServletResponse, java.lang.Object, java.lang.Exception) template method.

Specified by:

resolveException in interface HandlerExceptionResolver

Parameters:

request - current HTTP request

response - current HTTP response

handler - the executed handler, or null if none chosen at the time of the exception (for example, if multipart resolution failed)

ex - the exception that got thrown during handler execution

Returns:

a corresponding ModelAndView to forward to, or null for default processing

shouldApplyTo

protected boolean shouldApplyTo(HttpServletRequest request,
                                java.lang.Object handler)

Check whether this resolver is supposed to apply to the given handler.

The default implementation checks against the specified mapped handlers and handler classes, if any.

Parameters:

request - current HTTP request

handler - the executed handler, or null if none chosen at the time of the exception (for example, if multipart resolution failed)

Returns:

whether this resolved should proceed with resolving the exception for the given request and handler

See Also:

setMappedHandlers(java.util.Set<?>), setMappedHandlerClasses(java.lang.Class<?>[])

logException

protected void logException(java.lang.Exception ex,
                            HttpServletRequest request)

Log the given exception at warn level, provided that warn logging has been activated through the "warnLogCategory" property.

Calls buildLogMessage(java.lang.Exception, HttpServletRequest) in order to determine the concrete message to log. Always passes the full exception to the logger.

Parameters:

ex - the exception that got thrown during handler execution

request - current HTTP request (useful for obtaining metadata)

See Also:

setWarnLogCategory(java.lang.String), buildLogMessage(java.lang.Exception, HttpServletRequest), org.apache.commons.logging.Log#warn(Object, Throwable)

buildLogMessage

protected java.lang.String buildLogMessage(java.lang.Exception ex,
                                           HttpServletRequest request)

Build a log message for the given exception, occurred during processing the given request.

Parameters:

ex - the exception that got thrown during handler execution

request - current HTTP request (useful for obtaining metadata)

Returns:

the log message to use

prepareResponse

protected void prepareResponse(java.lang.Exception ex,
                               HttpServletResponse response)

Prepare the response for the exceptional case.

The default implementation prevents the response from being cached, if the "preventResponseCaching" property has been set to "true".

Parameters:

ex - the exception that got thrown during handler execution

response - current HTTP response

See Also:

preventCaching(HttpServletResponse)

preventCaching

protected void preventCaching(HttpServletResponse response)

Prevents the response from being cached, through setting corresponding HTTP headers. See http://www.mnot.net/cache_docs.

Parameters:

response - current HTTP response

doResolveException

protected abstract ModelAndView doResolveException(HttpServletRequest request,
                                                   HttpServletResponse response,
                                                   java.lang.Object handler,
                                                   java.lang.Exception ex)

Actually resolve the given exception that got thrown during on handler execution, returning a ModelAndView that represents a specific error page if appropriate.

May be overridden in subclasses, in order to apply specific exception checks. Note that this template method will be invoked after checking whether this resolved applies ("mappedHandlers" etc), so an implementation may simply proceed with its actual exception handling.

Parameters:

request - current HTTP request

response - current HTTP response

handler - the executed handler, or null if none chosen at the time of the exception (for example, if multipart resolution failed)

ex - the exception that got thrown during handler execution

Returns:

a corresponding ModelAndView to forward to, or null for default processing