ExceptionHandler

Annotation for handling exceptions in specific handler classes and/or handler methods.

Handler methods which are annotated with this annotation are allowed to have very flexible signatures. They may have parameters of the following types, in arbitrary order:

• An exception argument: declared as a general Exception or as a more specific exception. This also serves as a mapping hint if the annotation itself does not narrow the exception types through its #value().
• Request and/or response objects (typically from the Servlet API). You may choose any specific request/response type, e.g. javax.servlet.ServletRequest / javax.servlet.http.HttpServletRequest.
• Session object: typically javax.servlet.http.HttpSession. 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.
• org.springframework.web.context.request.WebRequest or org.springframework.web.context.request.NativeWebRequest. Allows for generic request parameter access as well as request/session attribute access, without ties to the native Servlet API.
• java.util.Locale for the current request locale (determined by the most specific locale resolver available, i.e. the configured org.springframework.web.servlet.LocaleResolver in a Servlet environment).
• java.io.InputStream / java.io.Reader for access to the request's content. This will be the raw InputStream/Reader as exposed by the Servlet API.
• java.io.OutputStream / java.io.Writer for generating the response's content. This will be the raw OutputStream/Writer as exposed by the Servlet API.
• org.springframework.ui.Model as an alternative to returning a model map from the handler method. Note that the provided model is not pre-populated with regular model attributes and therefore always empty, as a convenience for preparing the model for an exception-specific view.

The following return types are supported for handler methods:

• A ModelAndView object (from Servlet MVC).
• A org.springframework.ui.Model object, with the view name implicitly determined through a org.springframework.web.servlet.RequestToViewNameTranslator.
• A java.util.Map object for exposing a model, with the view name implicitly determined through a org.springframework.web.servlet.RequestToViewNameTranslator.
• A org.springframework.web.servlet.View object.
• A String value which is interpreted as view name.
• ResponseBody annotated methods (Servlet-only) to set the response content. The return value will be converted to the response stream using org.springframework.http.converter.HttpMessageConverter.
• An org.springframework.http.HttpEntity or org.springframework.http.ResponseEntity object (Servlet-only) to set response headers and content. The ResponseEntity body will be converted and written to the response stream using org.springframework.http.converter.HttpMessageConverter.
• void if the method handles the response itself (by writing the response content directly, declaring an argument of type javax.servlet.ServletResponse / javax.servlet.http.HttpServletResponse for that purpose) or if the view name is supposed to be implicitly determined through a org.springframework.web.servlet.RequestToViewNameTranslator (not declaring a response argument in the handler method signature).

In Servlet environments, you can combine the ExceptionHandler annotation with ResponseStatus, to define the response status for the HTTP response.

Author
Arjen Poutsma

Author
Juergen Hoeller

Since
3.0

See Also
org.springframework.web.context.request.WebRequest

Constructors

Properties