org.springframework.web.method.annotation

Class ModelFactory

java.lang.Object

org.springframework.web.method.annotation.ModelFactory

public final class ModelFactory
extends Object

Provides methods to initialize the Model before controller method invocation and to update it afterwards.

On initialization, the model is populated with attributes from the session and by invoking methods annotated with @ModelAttribute.

On update, model attributes are synchronized with the session and also BindingResult attributes are added where missing.

Since:

3.1

Author:

Rossen Stoyanchev

Constructor Summary

Constructors

Constructor and Description
ModelFactory(List<InvocableHandlerMethod> invocableMethods, WebDataBinderFactory dataBinderFactory, SessionAttributesHandler sessionAttributesHandler) Create a new instance with the given @ModelAttribute methods.

Method Summary

Modifier and Type	Method and Description
static String	getNameForParameter(MethodParameter parameter) Derives the model attribute name for a method parameter based on: The parameter @ModelAttribute annotation value The parameter type
static String	getNameForReturnValue(Object returnValue, MethodParameter returnType) Derive the model attribute name for the given return value using one of: The method ModelAttribute annotation value The declared return type if it is more specific than Object The actual return value type
void	initModel(NativeWebRequest request, ModelAndViewContainer mavContainer, HandlerMethod handlerMethod) Populate the model in the following order: Retrieve "known" session attributes listed as @SessionAttributes.
void	updateModel(NativeWebRequest request, ModelAndViewContainer mavContainer) 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(List<InvocableHandlerMethod> invocableMethods,
                    WebDataBinderFactory dataBinderFactory,
                    SessionAttributesHandler sessionAttributesHandler)

Create a new instance with the given @ModelAttribute methods.

Parameters:

invocableMethods - the @ModelAttribute methods to invoke

dataBinderFactory - for preparation of BindingResult attributes

sessionAttributesHandler - for access to session attributes

Method Detail

initModel

public void initModel(NativeWebRequest request,
                      ModelAndViewContainer mavContainer,
                      HandlerMethod handlerMethod)
               throws Exception

Populate the model in the following order:

1. Retrieve "known" session attributes listed as @SessionAttributes.
2. Invoke @ModelAttribute methods
3. 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

mavContainer - a container with the model to be initialized

handlerMethod - the method for which the model is initialized

Throws:

Exception - may arise from @ModelAttribute methods

getNameForParameter

public static String getNameForParameter(MethodParameter parameter)

Derives the model attribute name for a method parameter based on:

1. The parameter @ModelAttribute annotation value
2. The parameter type

Returns:

the derived name; never null or an empty string

getNameForReturnValue

public static String getNameForReturnValue(Object returnValue,
                                           MethodParameter returnType)

Derive the model attribute name for the given return value using one of:

1. The method ModelAttribute annotation value
2. The declared return type if it is more specific than Object
3. The actual return value type

Parameters:

returnValue - the value returned from a method invocation

returnType - the return type of the method

Returns:

the model name, never null nor empty

updateModel

public void updateModel(NativeWebRequest request,
                        ModelAndViewContainer mavContainer)
                 throws Exception

Promote model attributes listed as @SessionAttributes to the session. Add BindingResult attributes where necessary.

Parameters:

request - the current request

mavContainer - contains the model to update

Throws:

Exception - if creating BindingResult attributes fails