@Target(value=METHOD) @Retention(value=RUNTIME) @Documented public @interface ExceptionHandler
Handler methods which are annotated with this annotation are allowed to have very flexible signatures. They may have arguments of the following types, in arbitrary order:
RenderRequest. Note that in the Portlet case, an explicitly declared action/render argument is also used for mapping specific request types onto a handler method (in case of no other information given that differentiates between action and render requests).
PortletSession. An argument of this type will enforce the presence of a corresponding session. As a consequence, such an argument will never be
null. Note that session access may not be thread-safe, in particular in a Servlet environment: Consider switching the
"synchronizeOnSession"flag to "true" if multiple requests are allowed to access a session concurrently.
NativeWebRequest. Allows for generic request parameter access as well as request/session attribute access, without ties to the native Servlet/Portlet API.
Localefor the current request locale (determined by the most specific locale resolver available, i.e. the configured
LocaleResolverin a Servlet environment and the portal locale in a Portlet environment).
Readerfor access to the request's content. This will be the raw InputStream/Reader as exposed by the Servlet/Portlet API.
Writerfor generating the response's content. This will be the raw OutputStream/Writer as exposed by the Servlet/Portlet API.
The following return types are supported for handler methods:
ModelAndViewobject (Servlet MVC or Portlet MVC).
Modelobject, with the view name implicitly determined through a
Mapobject for exposing a model, with the view name implicitly determined through a
Stringvalue which is interpreted as view name.
@ResponseBodyannotated methods (Servlet-only) to set the response content. The return value will be converted to the response stream using message converters.
ResponseEntity<?>object (Servlet-only) to set response headers and content. The ResponseEntity body will be converted and written to the response stream using message converters.
voidif the method handles the response itself (by writing the response content directly, declaring an argument of type
RenderResponsefor that purpose) or if the view name is supposed to be implicitly determined through a
RequestToViewNameTranslator(not declaring a response argument in the handler method signature; only applicable in a Servlet environment).
In Servlet environments, you can combine the
@ResponseStatus, to define the response status
for the HTTP response.
Note: In Portlet environments,
ExceptionHandler annotated methods
will only be called during the render and resource phases - just like
HandlerExceptionResolver beans would.
Exceptions carried over from the action and event phases will be invoked during
the render phase as well, with exception handler methods having to be present
on the controller class that defines the applicable render method.