public class ServletContextScope extends Object implements Scope, DisposableBean
Scopewrapper for a ServletContext, i.e. for global web application attributes.
This differs from traditional Spring singletons in that it exposes attributes in the ServletContext. Those attributes will get destroyed whenever the entire application shuts down, which might be earlier or later than the shutdown of the containing Spring ApplicationContext.
The associated destruction mechanism relies on a
ContextCleanupListener being registered in
web.xml. Note that
includes ContextCleanupListener's functionality.
This scope is registered as default scope with key
|Constructor and Description|
Create a new Scope wrapper for the given ServletContext.
|Modifier and Type||Method and Description|
Invoke all registered destruction callbacks.
Return the object with the given name from the underlying scope,
Return the conversation ID for the current underlying scope, if any.
Register a callback to be executed on destruction of the specified object in the scope (or at destruction of the entire scope, if the scope does not destroy individual objects but rather only terminates in its entirety).
Remove the object with the given
Resolve the contextual object for the given key, if any.
public ServletContextScope(ServletContext servletContext)
servletContext- the ServletContext to wrap
public Object get(String name, ObjectFactory<?> objectFactory)
creating itif not found in the underlying storage mechanism.
This is the central operation of a Scope, and the only operation that is absolutely required.
name- the name of the object to retrieve
ObjectFactoryto use to create the scoped object if it is not present in the underlying storage mechanism
@Nullable public Object remove(String name)
namefrom the underlying scope.
null if no object was found; otherwise
returns the removed
Note that an implementation should also remove a registered destruction callback for the specified object, 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).
Note: This is an optional operation. Implementations may throw
UnsupportedOperationException if they do not support explicitly
removing an object.
name- the name of the object to remove
nullif no object was present
public void registerDestructionCallback(String name, Runnable callback)
Note: This is an optional operation. This method will only be called for scoped beans with actual destruction configuration (DisposableBean, destroy-method, DestructionAwareBeanPostProcessor). Implementations should do their best to execute a given callback at the appropriate time. If such a callback is not supported by the underlying runtime environment at all, the callback must be ignored and a corresponding warning should be logged.
Note that 'destruction' refers to automatic destruction of
the object as part of the scope's own lifecycle, not to the individual
scoped object having been explicitly removed by the application.
If a scoped object gets removed via this facade's
method, any registered destruction callback should be removed as well,
assuming that the removed object will be reused or manually destroyed.
name- the name of the object to execute the destruction callback for
callback- the destruction callback to be executed. Note that the passed-in Runnable will never throw an exception, so it can safely be executed without an enclosing try-catch block. Furthermore, the Runnable will usually be serializable, provided that its target object is serializable as well.
@Nullable public Object resolveContextualObject(String key)
key- the contextual key
nullif none found
@Nullable public String getConversationId()
The exact meaning of the conversation ID depends on the underlying
storage mechanism. In the case of session-scoped objects, the
conversation ID would typically be equal to (or derived from) the
session ID; in the
case of a custom conversation that sits within the overall session,
the specific ID for the current conversation would be appropriate.
Note: This is an optional operation. It is perfectly valid to
null in an implementation of this method if the
underlying storage mechanism has no obvious candidate for such an ID.
nullif there is no conversation ID for the current scope
public void destroy()