org.springframework.web.method.annotation

## Class ModelMethodProcessor

- java.lang.Object
- - org.springframework.web.method.annotation.ModelMethodProcessor

- All Implemented Interfaces:
    HandlerMethodArgumentResolver, HandlerMethodReturnValueHandler

      public class ModelMethodProcessor
      extends Object
      implements HandlerMethodArgumentResolver, HandlerMethodReturnValueHandler

  Resolves `Model` arguments and handles `Model` return values.

  A `Model` return type has a set purpose. Therefore this handler should be configured ahead of handlers that support any return value type annotated with `@ModelAttribute` or `@ResponseBody` to ensure they don't take over.

  Since:
    3.1
  Author:
    Rossen Stoyanchev

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `ModelMethodProcessor()`

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `void` | `handleReturnValue(Object returnValue, MethodParameter returnType, ModelAndViewContainer mavContainer, NativeWebRequest webRequest)` Handle the given return value by adding attributes to the model and setting a view or setting the `ModelAndViewContainer.setRequestHandled(boolean)` flag to `true` to indicate the response has been handled directly.
    `Object` | `resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer, NativeWebRequest webRequest, WebDataBinderFactory binderFactory)` Resolves a method parameter into an argument value from a given request.
    `boolean` | `supportsParameter(MethodParameter parameter)` Whether the given method parameter is supported by this resolver.
    `boolean` | `supportsReturnType(MethodParameter returnType)` Whether the given method return type is supported by this handler.

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Constructor Detail

    - #### ModelMethodProcessor

          public ModelMethodProcessor()

  - ### Method Detail

    - #### supportsParameter

          public boolean supportsParameter(MethodParameter parameter)

      Description copied from interface: `HandlerMethodArgumentResolver`
      Whether the given method parameter is supported by this resolver.
      Specified by:
        `supportsParameter` in interface `HandlerMethodArgumentResolver`
      Parameters:
        `parameter` - the method parameter to check
      Returns:
        `true` if this resolver supports the supplied parameter; `false` otherwise

    - #### resolveArgument

          public Object resolveArgument(MethodParameter parameter,
                               ModelAndViewContainer mavContainer,
                               NativeWebRequest webRequest,
                               WebDataBinderFactory binderFactory)
                                 throws Exception

      Description copied from interface: `HandlerMethodArgumentResolver`
      Resolves a method parameter into an argument value from a given request. A `ModelAndViewContainer` provides access to the model for the request. A `WebDataBinderFactory` provides a way to create a `WebDataBinder` instance when needed for data binding and type conversion purposes.
      Specified by:
        `resolveArgument` in interface `HandlerMethodArgumentResolver`
      Parameters:
        `parameter` - the method parameter to resolve. This parameter must have previously been passed to `HandlerMethodArgumentResolver.supportsParameter(org.springframework.core.MethodParameter)` and it must have returned `true`
        `mavContainer` - the ModelAndViewContainer for the current request
        `webRequest` - the current request
        `binderFactory` - a factory for creating `WebDataBinder` instances
      Returns:
        the resolved argument value, or `null`.
      Throws:
        `Exception` - in case of errors with the preparation of argument values

    - #### supportsReturnType

          public boolean supportsReturnType(MethodParameter returnType)

      Description copied from interface: `HandlerMethodReturnValueHandler`
      Whether the given method return type is supported by this handler.
      Specified by:
        `supportsReturnType` in interface `HandlerMethodReturnValueHandler`
      Parameters:
        `returnType` - the method return type to check
      Returns:
        `true` if this handler supports the supplied return type; `false` otherwise

    - #### handleReturnValue

          public void handleReturnValue(Object returnValue,
                               MethodParameter returnType,
                               ModelAndViewContainer mavContainer,
                               NativeWebRequest webRequest)
                                 throws Exception

      Description copied from interface: `HandlerMethodReturnValueHandler`
      Handle the given return value by adding attributes to the model and setting a view or setting the `ModelAndViewContainer.setRequestHandled(boolean)` flag to `true` to indicate the response has been handled directly.
      Specified by:
        `handleReturnValue` in interface `HandlerMethodReturnValueHandler`
      Parameters:
        `returnValue` - the value returned from the handler method
        `returnType` - the type of the return value. This type must have previously been passed to `HandlerMethodReturnValueHandler.supportsReturnType(org.springframework.core.MethodParameter)` and it must have returned `true`
        `mavContainer` - the ModelAndViewContainer for the current request
        `webRequest` - the current request
      Throws:
        `Exception` - if the return value handling results in an error