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

```
public final class ModelFactory
extends Object
```
Assist with initialization of the Model before controller method invocation and with updates to it after the invocation.
On initialization the model is populated with attributes temporarily stored in the session and through the invocation of @ModelAttribute methods.
On update model attributes are synchronized with the session and also BindingResult attributes are added if missing.
Since:
3.1
Author:
Rossen Stoyanchev

Constructor Summary

Constructors
Constructor	Description
`ModelFactory(List<InvocableHandlerMethod> handlerMethods, WebDataBinderFactory binderFactory, SessionAttributesHandler attributeHandler)`	Create a new instance with the given `@ModelAttribute` methods.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`static String`	`getNameForParameter(MethodParameter parameter)`	Derive the model attribute name for the given method parameter based on a `@ModelAttribute` parameter annotation (if present) or falling back on parameter type based conventions.
`static String`	`getNameForReturnValue(Object returnValue, MethodParameter returnType)`	Derive the model attribute name for the given return value.
`void`	`initModel(NativeWebRequest request, ModelAndViewContainer container, HandlerMethod handlerMethod)`	Populate the model in the following order: Retrieve "known" session attributes listed as `@SessionAttributes`.
`void`	`updateModel(NativeWebRequest request, ModelAndViewContainer container)`	Promote model attributes listed as `@SessionAttributes` to the session.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - ModelFactory
```
public ModelFactory(@Nullable
                    List<InvocableHandlerMethod> handlerMethods,
                    WebDataBinderFactory binderFactory,
                    SessionAttributesHandler attributeHandler)
```
    Create a new instance with the given @ModelAttribute methods.
    Parameters:
    handlerMethods - the @ModelAttribute methods to invoke
    binderFactory - for preparation of BindingResult attributes
    attributeHandler - for access to session attributes
- Method Detail
  - initModel
```
public void initModel(NativeWebRequest request,
                      ModelAndViewContainer container,
                      HandlerMethod handlerMethod)
               throws Exception
```
    Populate the model in the following order:
    Retrieve "known" session attributes listed as @SessionAttributes.
    Invoke @ModelAttribute methods
    Find @ModelAttribute method arguments also listed as @SessionAttributes and ensure they're present in the model raising an exception if necessary.
    Parameters:
    request - the current request
    container - a container with the model to be initialized
    handlerMethod - the method for which the model is initialized
    Throws:
    Exception - may arise from @ModelAttribute methods
  - updateModel
```
public void updateModel(NativeWebRequest request,
                        ModelAndViewContainer container)
                 throws Exception
```
    Promote model attributes listed as @SessionAttributes to the session. Add BindingResult attributes where necessary.
    Parameters:
    request - the current request
    container - contains the model to update
    Throws:
    Exception - if creating BindingResult attributes fails
  - getNameForParameter
```
public static String getNameForParameter(MethodParameter parameter)
```
    Derive the model attribute name for the given method parameter based on a @ModelAttribute parameter annotation (if present) or falling back on parameter type based conventions.
    Parameters:
    parameter - a descriptor for the method parameter
    Returns:
    the derived name
    See Also:
    Conventions.getVariableNameForParameter(MethodParameter)
  - getNameForReturnValue
```
public static String getNameForReturnValue(@Nullable
                                           Object returnValue,
                                           MethodParameter returnType)
```
    Derive the model attribute name for the given return value. Results will be based on:
    the method ModelAttribute annotation value
    the declared return type if it is more specific than Object
    the actual return value type
    Parameters:
    returnValue - the value returned from a method invocation
    returnType - a descriptor for the return type of the method
    Returns:
    the derived name (never null or empty String)

Class ModelFactory

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

ModelFactory

Method Detail

initModel

updateModel

getNameForParameter

getNameForReturnValue