Package org.springframework.web.method.annotation

Class ModelFactory

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

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 Details

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 Details

initModel

public void initModel(NativeWebRequest request,
 ModelAndViewContainer container,
 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

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:

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 - a descriptor for the return type of the method

Returns:

the derived name (never null or empty String)