Request or response objects (Servlet API). Choose any specific request or response type, for example ServletRequest or HttpServletRequest.

Session object (Servlet API) of type HttpSession. An argument of this type enforces the presence of a corresponding session. As a consequence, such an argument is never null.

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/Portlet API.

java.util.Locale for the current request locale, determined by the most specific locale resolver available, in effect, the configured LocaleResolver / LocaleContextResolver in an MVC environment.

java.util.TimeZone (Java 6+) / java.time.ZoneId (on Java 8) for the time zone associated with the current request, as determined by a LocaleContextResolver.

java.io.InputStream / java.io.Reader for access to the request’s content. This value is the raw InputStream/Reader as exposed by the Servlet API.

java.io.OutputStream / java.io.Writer for generating the response’s content. This value is the raw OutputStream/Writer as exposed by the Servlet API.

org.springframework.http.HttpMethod for the HTTP request method.

java.security.Principal containing the currently authenticated user.

@PathVariable annotated parameters for access to URI template variables. See [mvc-ann-requestmapping-uri-templates].

@MatrixVariable annotated parameters for access to name-value pairs located in URI path segments. See [mvc-ann-matrix-variables].

@RequestParam annotated parameters for access to specific Servlet request parameters. Parameter values are converted to the declared method argument type. See [mvc-ann-requestparam].

@RequestHeader annotated parameters for access to specific Servlet request HTTP headers. Parameter values are converted to the declared method argument type. See [mvc-ann-requestheader].

@RequestBody annotated parameters for access to the HTTP request body. Parameter values are converted to the declared method argument type using HttpMessageConverters. See [mvc-ann-requestbody].

@RequestPart annotated parameters for access to the content of a "multipart/form-data" request part. See [mvc-multipart-forms-non-browsers] and [mvc-multipart].

@SessionAttribute annotated parameters for access to existing, permanent session attributes (e.g. user authentication object) as opposed to model attributes temporarily stored in the session as part of a controller workflow via @SessionAttributes.

@RequestAttribute annotated parameters for access to request attributes.

HttpEntity<?> parameters for access to the Servlet request HTTP headers and contents. The request stream will be converted to the entity body using HttpMessageConverters. See [mvc-ann-httpentity].

java.util.Map / org.springframework.ui.Model / org.springframework.ui.ModelMap for enriching the implicit model that is exposed to the web view.

org.springframework.web.servlet.mvc.support.RedirectAttributes to specify the exact set of attributes to use in case of a redirect and also to add flash attributes (attributes stored temporarily on the server-side to make them available to the request after the redirect). See [mvc-redirecting-passing-data] and [mvc-flash-attributes].

Command or form objects to bind request parameters to bean properties (via setters) or directly to fields, with customizable type conversion, depending on @InitBinder methods and/or the HandlerAdapter configuration. See the webBindingInitializer property on RequestMappingHandlerAdapter. Such command objects along with their validation results will be exposed as model attributes by default, using the command class name - e.g. model attribute "orderAddress" for a command object of type "some.package.OrderAddress". The ModelAttribute annotation can be used on a method argument to customize the model attribute name used.

org.springframework.validation.Errors / org.springframework.validation.BindingResult validation results for a preceding command or form object (the immediately preceding method argument).

org.springframework.web.bind.support.SessionStatus status handle for marking form processing as complete, which triggers the cleanup of session attributes that have been indicated by the @SessionAttributes annotation at the handler type level.

org.springframework.web.util.UriComponentsBuilder a builder for preparing a URL relative to the current request’s host, port, scheme, context path, and the literal part of the servlet mapping.

A ModelAndView object, with the model implicitly enriched with command objects and the results of @ModelAttribute annotated reference data accessor methods.

A Model object, with the view name implicitly determined through a RequestToViewNameTranslator and the model implicitly enriched with command objects and the results of @ModelAttribute annotated reference data accessor methods.

A Map object for exposing a model, with the view name implicitly determined through a RequestToViewNameTranslator and the model implicitly enriched with command objects and the results of @ModelAttribute annotated reference data accessor methods.

A View object, with the model implicitly determined through command objects and @ModelAttribute annotated reference data accessor methods. The handler method may also programmatically enrich the model by declaring a Model argument (see above).

A String value that is interpreted as the logical view name, with the model implicitly determined through command objects and @ModelAttribute annotated reference data accessor methods. The handler method may also programmatically enrich the model by declaring a Model argument (see above).

void if the method handles the response itself (by writing the response content directly, declaring an argument of type ServletResponse / HttpServletResponse for 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).

If the method is annotated with @ResponseBody, the return type is written to the response HTTP body. The return value will be converted to the declared method argument type using HttpMessageConverters. See [mvc-ann-responsebody].

An HttpEntity<?> or ResponseEntity<?> object to provide access to the Servlet response HTTP headers and contents. The entity body will be converted to the response stream using HttpMessageConverters. See [mvc-ann-httpentity].

An HttpHeaders object to return a response with no body.

A Callable<?> can be returned when the application wants to produce the return value asynchronously in a thread managed by Spring MVC.

A DeferredResult<?> can be returned when the application wants to produce the return value from a thread of its own choosing.

A ListenableFuture<?> can be returned when the application wants to produce the return value from a thread of its own choosing.

A ResponseBodyEmitter can be returned to write multiple objects to the response asynchronously; also supported as the body within a ResponseEntity.

An SseEmitter can be returned to write Server-Sent Events to the response asynchronously; also supported as the body within a ResponseEntity.

A StreamingResponseBody can be returned to write to the response OutputStream asynchronously; also supported as the body within a ResponseEntity.

Any other return type is considered to be a single model attribute to be exposed to the view, using the attribute name specified through @ModelAttribute at the method level (or the default attribute name based on the return type class name). The model is implicitly enriched with command objects and the results of @ModelAttribute annotated reference data accessor methods.