The Spring Framework

## org.springframework.web.servlet.handler
Class SimpleMappingExceptionResolver

    java.lang.Object
      org.springframework.web.servlet.handler.SimpleMappingExceptionResolver

All Implemented Interfaces:
  Ordered, HandlerExceptionResolver

    public class SimpleMappingExceptionResolver

extends Object
implements HandlerExceptionResolver, Ordered

`HandlerExceptionResolver` implementation that allows for mapping exception class names to view names, either for a set of given handlers or for all handlers in the DispatcherServlet.

Error views are analogous to error page JSPs, but can be used with any kind of exception including any checked one, with fine-granular mappings for specific handlers.

Since:
  22.11.2003
Author:
  Juergen Hoeller
See Also:
  `DispatcherServlet`

Field Summary
`static String` `DEFAULT_EXCEPTION_ATTRIBUTE` The default name of the exception attribute: "exception".
`protected Log` `logger` Logger available to subclasses

Fields inherited from interface org.springframework.core.Ordered
`HIGHEST_PRECEDENCE, LOWEST_PRECEDENCE`

Constructor Summary
`SimpleMappingExceptionResolver()`

Method Summary
`protected void` `applyStatusCodeIfPossible(HttpServletRequest request, HttpServletResponse response, int statusCode)` Apply the specified HTTP status code to the given response, if possible (that is, if not executing within an include request).
`protected String` `buildLogMessage(Exception ex, HttpServletRequest request)` Build a log message for the given exception, occured during processing the given request.
`protected Integer` `determineStatusCode(HttpServletRequest request, String viewName)` Determine the HTTP status code to apply for the given error view.
`protected String` `determineViewName(Exception ex, HttpServletRequest request)` Determine the view name for the given exception, searching the `"exceptionMappings"`, using the `"defaultErrorView"` as fallback.
`protected ModelAndView` `doResolveException(HttpServletRequest request, HttpServletResponse response, Object handler, 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.
`protected String` `findMatchingViewName(Properties exceptionMappings, Exception ex)` Find a matching view name in the given exception mappings.
`protected int` `getDepth(String exceptionMapping, Exception ex)` Return the depth to the superclass matching.
`protected ModelAndView` `getModelAndView(String viewName, Exception ex)` Return a ModelAndView for the given view name and exception.
`protected ModelAndView` `getModelAndView(String viewName, Exception ex, HttpServletRequest request)` Return a ModelAndView for the given request, view name and exception.
`int` `getOrder()` Return the order value of this object, with a higher value meaning greater in terms of sorting.
`protected void` `logException(Exception ex, HttpServletRequest request)` Log the given exception at warn level, provided that warn logging has been activated through the `"warnLogCategory"` property.

`ModelAndView`

`resolveException(HttpServletRequest request, HttpServletResponse response, Object handler, 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(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse, java.lang.Object, java.lang.Exception)` template method.

`void` `setDefaultErrorView(String defaultErrorView)` Set the name of the default error view.
`void` `setDefaultStatusCode(int defaultStatusCode)` Set the default HTTP status code that this exception resolver will apply if it resolves an error view.
`void` `setExceptionAttribute(String exceptionAttribute)` Set the name of the model attribute as which the exception should be exposed.
`void` `setExceptionMappings(Properties mappings)` Set the mappings between exception class names and error view names.
`void` `setMappedHandlerClasses(Class[] mappedHandlerClasses)` Specify the set of classes that this exception resolver should apply to.
`void` `setMappedHandlers(Set mappedHandlers)` Specify the set of handlers that this exception resolver should apply to.
`void` `setOrder(int order)`
`void` `setWarnLogCategory(String loggerName)` Set the log category for warn logging.
`protected boolean` `shouldApplyTo(HttpServletRequest request, 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

### DEFAULT_EXCEPTION_ATTRIBUTE

    public static final String DEFAULT_EXCEPTION_ATTRIBUTE

  The default name of the exception attribute: "exception".

  See Also:
    Constant Field Values

### logger

    protected final Log logger

  Logger available to subclasses

Constructor Detail

### SimpleMappingExceptionResolver

    public SimpleMappingExceptionResolver()

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 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`

### setMappedHandlers

    public void setMappedHandlers(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(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(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, javax.servlet.http.HttpServletRequest)` method for custom logging.

  See Also:
    `LogFactory.getLog(String)`, `Logger.getLogger(String)`, `Logger.getLogger(String)`

### setExceptionMappings

    public void setExceptionMappings(Properties mappings)

  Set the mappings between exception class names and error view names. The exception class name can be a substring, with no wildcard support at present. A value of "ServletException" would match `javax.servlet.ServletException` and subclasses, for example.

  NB: Consider carefully how specific the pattern is, and whether to include package information (which isn't mandatory). For example, "Exception" will match nearly anything, and will probably hide other rules. "java.lang.Exception" would be correct if "Exception" was meant to define a rule for all checked exceptions. With more unusual exception names such as "BaseBusinessException" there's no need to use a FQN.

  Follows the same matching algorithm as RuleBasedTransactionAttribute and RollbackRuleAttribute.

  Parameters:
    `mappings` - exception patterns (can also be fully qualified class names) as keys, and error view names as values
  See Also:
    `RuleBasedTransactionAttribute`, `RollbackRuleAttribute`

### setDefaultErrorView

    public void setDefaultErrorView(String defaultErrorView)

  Set the name of the default error view. This view will be returned if no specific mapping was found.

  Default is none.

### setDefaultStatusCode

    public void setDefaultStatusCode(int defaultStatusCode)

  Set the default HTTP status code that this exception resolver will apply if it resolves an error view.

  Note that this error code will only get applied in case of a top-level request. It will not be set for an include request, since the HTTP status cannot be modified from within an include.

  If not specified, no status code will be applied, either leaving this to the controller or view, or keeping the servlet engine's default of 200 (OK).

  Parameters:
    `defaultStatusCode` - HTTP status code value, for example 500 (SC_INTERNAL_SERVER_ERROR) or 404 (SC_NOT_FOUND)
  See Also:
    `HttpServletResponse.SC_INTERNAL_SERVER_ERROR`, `HttpServletResponse.SC_NOT_FOUND`

### setExceptionAttribute

    public void setExceptionAttribute(String exceptionAttribute)

  Set the name of the model attribute as which the exception should be exposed. Default is "exception".

  This can be either set to a different attribute name or to `null` for not exposing an exception attribute at all.

  See Also:
    `DEFAULT_EXCEPTION_ATTRIBUTE`

### resolveException

    public ModelAndView resolveException(HttpServletRequest request,
                                         HttpServletResponse response,
                                         Object handler,
                                         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(javax.servlet.http.HttpServletRequest, javax.servlet.http.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,
                                    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[])`

### doResolveException

    protected ModelAndView doResolveException(HttpServletRequest request,
                                              HttpServletResponse response,
                                              Object handler,
                                              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

### logException

    protected void logException(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, javax.servlet.http.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, javax.servlet.http.HttpServletRequest)`, `Log.warn(Object, Throwable)`

### buildLogMessage

    protected String buildLogMessage(Exception ex,
                                     HttpServletRequest request)

  Build a log message for the given exception, occured 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

### determineViewName

    protected String determineViewName(Exception ex,
                                       HttpServletRequest request)

  Determine the view name for the given exception, searching the `"exceptionMappings"`, using the `"defaultErrorView"` as fallback.

  Parameters:
    `ex` - the exception that got thrown during handler execution
    `request` - current HTTP request (useful for obtaining metadata)
  Returns:
    the resolved view name, or `null` if none found

### findMatchingViewName

    protected String findMatchingViewName(Properties exceptionMappings,
                                          Exception ex)

  Find a matching view name in the given exception mappings.

  Parameters:
    `exceptionMappings` - mappings between exception class names and error view names
    `ex` - the exception that got thrown during handler execution
  Returns:
    the view name, or `null` if none found
  See Also:
    `setExceptionMappings(java.util.Properties)`

### getDepth

    protected int getDepth(String exceptionMapping,
                           Exception ex)

  Return the depth to the superclass matching.

  0 means ex matches exactly. Returns -1 if there's no match. Otherwise, returns depth. Lowest depth wins.

  Follows the same algorithm as `RollbackRuleAttribute`.

### determineStatusCode

    protected Integer determineStatusCode(HttpServletRequest request,
                                          String viewName)

  Determine the HTTP status code to apply for the given error view.

  The default implementation always returns the specified `"defaultStatusCode"`, as a common status code for all error views. Override this in a custom subclass to determine a specific status code for the given view.

  Parameters:
    `request` - current HTTP request
    `viewName` - the name of the error view
  Returns:
    the HTTP status code to use, or `null` for the servlet container's default (200 in case of a standard error view)
  See Also:
    `setDefaultStatusCode(int)`, `applyStatusCodeIfPossible(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse, int)`

### applyStatusCodeIfPossible

    protected void applyStatusCodeIfPossible(HttpServletRequest request,
                                             HttpServletResponse response,
                                             int statusCode)

  Apply the specified HTTP status code to the given response, if possible (that is, if not executing within an include request).

  Parameters:
    `request` - current HTTP request
    `response` - current HTTP response
    `statusCode` - the status code to apply
  See Also:
    `determineStatusCode(javax.servlet.http.HttpServletRequest, java.lang.String)`, `setDefaultStatusCode(int)`, `HttpServletResponse.setStatus(int)`

### getModelAndView

    protected ModelAndView getModelAndView(String viewName,
                                           Exception ex,
                                           HttpServletRequest request)

  Return a ModelAndView for the given request, view name and exception.

  The default implementation delegates to `getModelAndView(String, Exception)`.

  Parameters:
    `viewName` - the name of the error view
    `ex` - the exception that got thrown during handler execution
    `request` - current HTTP request (useful for obtaining metadata)
  Returns:
    the ModelAndView instance

### getModelAndView

    protected ModelAndView getModelAndView(String viewName,
                                           Exception ex)

  Return a ModelAndView for the given view name and exception.

  The default implementation adds the specified exception attribute. Can be overridden in subclasses.

  Parameters:
    `viewName` - the name of the error view
    `ex` - the exception that got thrown during handler execution
  Returns:
    the ModelAndView instance
  See Also:
    `setExceptionAttribute(java.lang.String)`

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