public interface

RequestAttributes

org.springframework.web.context.request.RequestAttributes
Known Indirect Subclasses

Class Overview

Abstraction for accessing attribute objects associated with a request. Supports access to request-scoped attributes as well as to session-scoped attributes, with the optional notion of a "global session".

Can be implemented for any kind of request/session mechanism, in particular for servlet requests and portlet requests.

See Also

Summary

Constants
String REFERENCE_REQUEST Name of the standard reference to the request object: "request".
String REFERENCE_SESSION Name of the standard reference to the session object: "session".
int SCOPE_GLOBAL_SESSION Constant that indicates global session scope.
int SCOPE_REQUEST Constant that indicates request scope.
int SCOPE_SESSION Constant that indicates session scope.
Public Methods
abstract Object getAttribute(String name, int scope)
Return the value for the scoped attribute of the given name, if any.
abstract String[] getAttributeNames(int scope)
Retrieve the names of all attributes in the scope.
abstract String getSessionId()
Return an id for the current underlying session.
abstract Object getSessionMutex()
Expose the best available mutex for the underlying session: that is, an object to synchronize on for the underlying session.
abstract void registerDestructionCallback(String name, Runnable callback, int scope)
Register a callback to be executed on destruction of the specified attribute in the given scope.
abstract void removeAttribute(String name, int scope)
Remove the scoped attribute of the given name, if it exists.
abstract Object resolveReference(String key)
Resolve the contextual reference for the given key, if any.
abstract void setAttribute(String name, Object value, int scope)
Set the value for the scoped attribute of the given name, replacing an existing value (if any).

Constants

public static final String REFERENCE_REQUEST

Name of the standard reference to the request object: "request".

See Also
Constant Value: "request"

public static final String REFERENCE_SESSION

Name of the standard reference to the session object: "session".

See Also
Constant Value: "session"

public static final int SCOPE_GLOBAL_SESSION

Constant that indicates global session scope.

This explicitly refers to a globally shared session, if such a distinction is available (for example, in a Portlet environment). Else, it simply refers to the common session.

Constant Value: 2 (0x00000002)

public static final int SCOPE_REQUEST

Constant that indicates request scope.

Constant Value: 0 (0x00000000)

public static final int SCOPE_SESSION

Constant that indicates session scope.

This preferably refers to a locally isolated session, if such a distinction is available (for example, in a Portlet environment). Else, it simply refers to the common session.

Constant Value: 1 (0x00000001)

Public Methods

public abstract Object getAttribute (String name, int scope)

Return the value for the scoped attribute of the given name, if any.

Parameters
name the name of the attribute
scope the scope identifier
Returns
  • the current attribute value, or null if not found

public abstract String[] getAttributeNames (int scope)

Retrieve the names of all attributes in the scope.

Parameters
scope the scope identifier
Returns
  • the attribute names as String array

public abstract String getSessionId ()

Return an id for the current underlying session.

Returns
  • the session id as String (never null

public abstract Object getSessionMutex ()

Expose the best available mutex for the underlying session: that is, an object to synchronize on for the underlying session.

Returns
  • the session mutex to use (never null

public abstract void registerDestructionCallback (String name, Runnable callback, int scope)

Register a callback to be executed on destruction of the specified attribute in the given scope.

Implementations should do their best to execute the callback at the appropriate time: that is, at request completion or session termination, respectively. If such a callback is not supported by the underlying runtime environment, the callback must be ignored and a corresponding warning should be logged.

Note that 'destruction' usually corresponds to destruction of the entire scope, not to the individual attribute having been explicitly removed by the application. If an attribute gets removed via this facade's removeAttribute(String, int) method, any registered destruction callback should be disabled as well, assuming that the removed object will be reused or manually destroyed.

NOTE: Callback objects should generally be serializable if they are being registered for a session scope. Otherwise the callback (or even the entire session) might not survive web app restarts.

Parameters
name the name of the attribute to register the callback for
callback the destruction callback to be executed
scope the scope identifier

public abstract void removeAttribute (String name, int scope)

Remove the scoped attribute of the given name, if it exists.

Note that an implementation should also remove a registered destruction callback for the specified attribute, if any. It does, however, not need to execute a registered destruction callback in this case, since the object will be destroyed by the caller (if appropriate).

Parameters
name the name of the attribute
scope the scope identifier

public abstract Object resolveReference (String key)

Resolve the contextual reference for the given key, if any.

At a minimum: the HttpServletRequest/PortletRequest reference for key "request", and the HttpSession/PortletSession reference for key "session".

Parameters
key the contextual key
Returns
  • the corresponding object, or null if none found

public abstract void setAttribute (String name, Object value, int scope)

Set the value for the scoped attribute of the given name, replacing an existing value (if any).

Parameters
name the name of the attribute
value the value for the attribute
scope the scope identifier