Package org.springframework.web.context.request

Interface RequestAttributes

All Known Subinterfaces:
AsyncWebRequest, NativeWebRequest, WebRequest
All Known Implementing Classes:
AbstractRequestAttributes, DispatcherServletWebRequest, FacesRequestAttributes, FacesWebRequest, ServletRequestAttributes, ServletWebRequest, StandardServletAsyncWebRequest
public interface RequestAttributes
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.

Since:
2.0
Author:
Juergen Hoeller
See Also:

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final String
    REFERENCE_REQUEST
    Name of the standard reference to the request object: "request".
    static final String
    REFERENCE_SESSION
    Name of the standard reference to the session object: "session".
    static final int
    SCOPE_REQUEST
    Constant that indicates request scope.
    static final int
    SCOPE_SESSION
    Constant that indicates session scope.

  • Method Summary

    Modifier and Type
    Method
    Description
    Object
    getAttribute(String name, int scope)
    Return the value for the scoped attribute of the given name, if any.
    String[]
    getAttributeNames(int scope)
    Retrieve the names of all attributes in the scope.
    String
    getSessionId()
    Return an id for the current underlying session.
    Object
    getSessionMutex()
    Expose the best available mutex for the underlying session: that is, an object to synchronize on for the underlying session.
    void
    registerDestructionCallback(String name, Runnable callback, int scope)
    Register a callback to be executed on destruction of the specified attribute in the given scope.
    void
    removeAttribute(String name, int scope)
    Remove the scoped attribute of the given name, if it exists.
    Object
    resolveReference(String key)
    Resolve the contextual reference for the given key, if any.
    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).

  • Field Details

  • Method Details

    • getAttribute

      @Nullable 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

    • setAttribute

      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
      scope - the scope identifier
      value - the value for the attribute

    • removeAttribute

      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

    • getAttributeNames

      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

    • registerDestructionCallback

      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

    • resolveReference

      @Nullable Object resolveReference(String key)
      Resolve the contextual reference for the given key, if any.

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

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

    • getSessionId

      String getSessionId()
      Return an id for the current underlying session.
      Returns:
      the session id as String (never null)

    • getSessionMutex

      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)