Spring MVC 3 Action 支持的参数

请求类型

Handler methods that are annotated with @RequestMapping can have very flexible signatures. They may have arguments of the following types, in arbitrary order (except for validation results, which need to follow right after the corresponding command object, if desired):

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

• 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.

  Note

  Session access may not be thread-safe, in particular in a Servlet environment. Consider setting theAnnotationMethodHandlerAdapter's "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/Portlet API.

• java.util.Locale for the current request locale, determined by the most specific locale resolver available, in effect, the configured LocaleResolver in a Servlet environment.

• 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.

• @PathVariable annotated parameters for access to URI template variables. See Section 15.3.2.1, “URI Templates”.

• @RequestParam annotated parameters for access to specific Servlet request parameters. Parameter values are converted to the declared method argument type. See Section 15.3.2.4, “Binding request parameters to method parameters with @RequestParam”.

• @RequestHeader annotated parameters for access to specific Servlet request HTTP headers. Parameter values are converted to the declared method argument type.

• @RequestBody annotated parameters for access to the HTTP request body. Parameter values are converted to the declared method argument type using HttpMessageConverters. See Section 15.3.2.5, “Mapping the request body with the @RequestBody annotation”.

• 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 Section 15.3.2.7, “Using HttpEntity<?>”.

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

• Command or form objects to bind parameters to: as bean properties or fields, with customizable type conversion, depending on@InitBinder methods and/or the HandlerAdapter configuration. See the webBindingInitializer property onAnnotationMethodHandlerAdapter. Such command objects along with their validation results will be exposed as model attributes by default, using the non-qualified command class name in property notation. For example, "orderAddress" for type "mypackage.OrderAddress". Specify a parameter-level ModelAttribute annotation for declaring a specific model attribute name.

• 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.

  返回类型：

  • 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 typeServletResponse / HttpServletResponse for that purpose) or if the view name is supposed to be implicitly determined through aRequestToViewNameTranslator (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 Section 15.3.2.6, “Mapping the response body with the @ResponseBody annotation”.

  • A HttpEntity<?> or ResponseEntity<?> object to access to the Servlet reponse HTTP headers and contents. The entity body will be converted to the response stream using HttpMessageConverters. See Section 15.3.2.7, “Using HttpEntity<?>”.

  • 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.