org.springframework.web.method.annotation

Class SessionAttributesHandler

java.lang.Object

org.springframework.web.method.annotation.SessionAttributesHandler

public class SessionAttributesHandler
extends java.lang.Object

Manages controller-specific session attributes declared via @SessionAttributes. Actual storage is delegated to a SessionAttributeStore instance.

When a controller annotated with @SessionAttributes adds attributes to its model, those attributes are checked against names and types specified via @SessionAttributes. Matching model attributes are saved in the HTTP session and remain there until the controller calls SessionStatus.setComplete().

Since:

3.1

Author:

Rossen Stoyanchev

Field Summary

Fields

Modifier and Type	Field and Description
private java.util.Set<java.lang.String>	attributeNames
private java.util.Set<java.lang.Class<?>>	attributeTypes
private java.util.Set<java.lang.String>	knownAttributeNames
private SessionAttributeStore	sessionAttributeStore

Constructor Summary

Constructors

Constructor and Description
SessionAttributesHandler(java.lang.Class<?> handlerType, SessionAttributeStore sessionAttributeStore) Create a new instance for a controller type.

Method Summary

Modifier and Type	Method and Description
void	cleanupAttributes(WebRequest request) Remove "known" attributes from the session, i.e.
boolean	hasSessionAttributes() Whether the controller represented by this instance has declared any session attributes through an SessionAttributes annotation.
boolean	isHandlerSessionAttribute(java.lang.String attributeName, java.lang.Class<?> attributeType) Whether the attribute name or type match the names and types specified via @SessionAttributes in underlying controller.
(package private) java.lang.Object	retrieveAttribute(WebRequest request, java.lang.String attributeName) A pass-through call to the underlying SessionAttributeStore.
java.util.Map<java.lang.String,java.lang.Object>	retrieveAttributes(WebRequest request) Retrieve "known" attributes from the session, i.e.
void	storeAttributes(WebRequest request, java.util.Map<java.lang.String,?> attributes) Store a subset of the given attributes in the session.

Methods inherited from class java.lang.Object

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

Field Detail

attributeNames

private final java.util.Set<java.lang.String> attributeNames

attributeTypes

private final java.util.Set<java.lang.Class<?>> attributeTypes

knownAttributeNames

private final java.util.Set<java.lang.String> knownAttributeNames

sessionAttributeStore

private final SessionAttributeStore sessionAttributeStore

Constructor Detail

SessionAttributesHandler

public SessionAttributesHandler(java.lang.Class<?> handlerType,
                                SessionAttributeStore sessionAttributeStore)

Create a new instance for a controller type. Session attribute names and types are extracted from the @SessionAttributes annotation, if present, on the given type.

Parameters:

handlerType - the controller type

sessionAttributeStore - used for session access

Method Detail

hasSessionAttributes

public boolean hasSessionAttributes()

Whether the controller represented by this instance has declared any session attributes through an SessionAttributes annotation.

isHandlerSessionAttribute

public boolean isHandlerSessionAttribute(java.lang.String attributeName,
                                         java.lang.Class<?> attributeType)

Whether the attribute name or type match the names and types specified via @SessionAttributes in underlying controller.

Attributes successfully resolved through this method are "remembered" and subsequently used in retrieveAttributes(WebRequest) and cleanupAttributes(WebRequest).

Parameters:

attributeName - the attribute name to check, never null

attributeType - the type for the attribute, possibly null

storeAttributes

public void storeAttributes(WebRequest request,
                            java.util.Map<java.lang.String,?> attributes)

Store a subset of the given attributes in the session. Attributes not declared as session attributes via @SessionAttributes are ignored.

Parameters:

request - the current request

attributes - candidate attributes for session storage

retrieveAttributes

public java.util.Map<java.lang.String,java.lang.Object> retrieveAttributes(WebRequest request)

Retrieve "known" attributes from the session, i.e. attributes listed by name in @SessionAttributes or attributes previously stored in the model that matched by type.

Parameters:

request - the current request

Returns:

a map with handler session attributes, possibly empty

cleanupAttributes

public void cleanupAttributes(WebRequest request)

Remove "known" attributes from the session, i.e. attributes listed by name in @SessionAttributes or attributes previously stored in the model that matched by type.

Parameters:

request - the current request

retrieveAttribute

java.lang.Object retrieveAttribute(WebRequest request,
                                   java.lang.String attributeName)

A pass-through call to the underlying SessionAttributeStore.

Parameters:

request - the current request

attributeName - the name of the attribute of interest

Returns:

the attribute value or null