org.springframework.web.servlet.handler

## Class SimpleMappingExceptionResolver

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

- All Implemented Interfaces:
    Ordered, HandlerExceptionResolver

      public class SimpleMappingExceptionResolver
      extends AbstractHandlerExceptionResolver

  `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, Arjen Poutsma, Rossen Stoyanchev
  See Also:
    `DispatcherServlet`

- - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `static String` | `DEFAULT_EXCEPTION_ATTRIBUTE` The default name of the exception attribute: "exception".

    - ### Fields inherited from class org.springframework.web.servlet.handler.AbstractHandlerExceptionResolver

      `logger`

    - ### Fields inherited from interface org.springframework.core.Ordered

      `HIGHEST_PRECEDENCE, LOWEST_PRECEDENCE`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `SimpleMappingExceptionResolver()`

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `void` | `addStatusCode(String viewName, int statusCode)` An alternative to `setStatusCodes(Properties)` for use with Java-based configuration.
    `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 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, first checking against the `"excludedExecptions"`, then searching the `"exceptionMappings"`, and finally using the `"defaultErrorView"` as a 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.
    `Map<String,Integer>` | `getStatusCodesAsMap()` Returns the HTTP status codes provided via `setStatusCodes(Properties)`.
    `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 and if there is no status code mapping defined.
    `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` | `setExcludedExceptions(Class<?>... excludedExceptions)` Set one or more exceptions to be excluded from the exception mappings.
    `void` | `setStatusCodes(Properties statusCodes)` Set the HTTP status code that this exception resolver will apply for a given resolved error view.

    - ### Methods inherited from class org.springframework.web.servlet.handler.AbstractHandlerExceptionResolver

      `buildLogMessage, getOrder, logException, prepareResponse, preventCaching, resolveException, setMappedHandlerClasses, setMappedHandlers, setOrder, setPreventResponseCaching, setWarnLogCategory, shouldApplyTo`

    - ### 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

  - ### Constructor Detail

    - #### SimpleMappingExceptionResolver

          public SimpleMappingExceptionResolver()

  - ### Method Detail

    - #### 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.

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

    - #### setExcludedExceptions

          public void setExcludedExceptions(Class<?>... excludedExceptions)

      Set one or more exceptions to be excluded from the exception mappings. Excluded exceptions are checked first and if one of them equals the actual exception, the exception will remain unresolved.
      Parameters:
        `excludedExceptions` - one or more excluded exception types

    - #### 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.

    - #### setStatusCodes

          public void setStatusCodes(Properties statusCodes)

      Set the HTTP status code that this exception resolver will apply for a given resolved error view. Keys are view names; values are status codes.

      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, the default status code will be applied.

      See Also:
        `setDefaultStatusCode(int)`

    - #### addStatusCode

          public void addStatusCode(String viewName,
                                    int statusCode)

      An alternative to `setStatusCodes(Properties)` for use with Java-based configuration.

    - #### getStatusCodesAsMap

          public Map<String,Integer> getStatusCodesAsMap()

      Returns the HTTP status codes provided via `setStatusCodes(Properties)`. Keys are view names; values are status codes.

    - #### setDefaultStatusCode

          public void setDefaultStatusCode(int defaultStatusCode)

      Set the default HTTP status code that this exception resolver will apply if it resolves an error view and if there is no status code mapping defined.

      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 (`HttpServletResponse.SC_INTERNAL_SERVER_ERROR`) or 404 (`HttpServletResponse.SC_NOT_FOUND`)
      See Also:
        `setStatusCodes(Properties)`

    - #### 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`

    - #### 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.

      Specified by:
        `doResolveException` in class `AbstractHandlerExceptionResolver`
      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

    - #### determineViewName

          protected String determineViewName(Exception ex,
                                             HttpServletRequest request)

      Determine the view name for the given exception, first checking against the `"excludedExecptions"`, then searching the `"exceptionMappings"`, and finally using the `"defaultErrorView"` as a 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 excluded or 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.

    - #### determineStatusCode

          protected Integer determineStatusCode(HttpServletRequest request,
                                                String viewName)

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

      The default implementation returns the status code for the given view name (specified through the `statusCodes` property), or falls back to the `defaultStatusCode` if there is no match.

      Override this in a custom subclass to customize this behavior.

      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)`