Spring Beans 6.1.4 · org.springframework.beans.factory.config.Scope

Strategy interface used by a ConfigurableBeanFactory, representing a target scope to hold bean instances in. This allows for extending the BeanFactory's standard scopes "singleton" and "prototype" with custom further scopes, registered for a specific key.

org.springframework.context.ApplicationContext implementations such as a org.springframework.web.context.WebApplicationContext may register additional standard scopes specific to their environment, e.g. "request" and "session", based on this Scope SPI.

Even if its primary use is for extended scopes in a web environment, this SPI is completely generic: It provides the ability to get and put objects from any underlying storage mechanism, such as an HTTP session or a custom conversation mechanism. The name passed into this class's get and remove methods will identify the target object in the current scope.

Scope implementations are expected to be thread-safe. One Scope instance can be used with multiple bean factories at the same time, if desired (unless it explicitly wants to be aware of the containing BeanFactory), with any number of threads accessing the Scope concurrently from any number of factories.

Method Summary

Modifier and Type	Method and Description
public Object	Returns: the desired object (never `null`) get(String the name of the object to retrieve name, ObjectFactory<?> the `ObjectFactory` to use to create the scoped object if it is not present in the underlying storage mechanism objectFactory) Return the object with the given name from the underlying scope, `creating it` if not found in the underlying storage mechanism.
public String	Returns: the conversation ID, or `null` if there is no conversation ID for the current scope getConversationId() Return the conversation ID for the current underlying scope, if any.
public void	registerDestructionCallback(String the name of the object to execute the destruction callback for name, Runnable 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. callback) 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).
public Object	Returns: the removed object, or `null` if no object was present remove(String the name of the object to remove name) Remove the object with the given `name` from the underlying scope.
public Object	Returns: the corresponding object, or `null` if none found resolveContextualObject(String the contextual key key) Resolve the contextual object for the given key, if any.

Method Detail

get back to summary

get	back to summary
public Object get(String name, ObjectFactory<?> objectFactory) Return the object with the given name from the underlying scope, `creating it` if not found in the underlying storage mechanism. This is the central operation of a Scope, and the only operation that is absolutely required. Parameters name:String the name of the object to retrieve objectFactory:ObjectFactory<?> the `ObjectFactory` to use to create the scoped object if it is not present in the underlying storage mechanism Returns:Object the desired object (never `null`) Exceptions IllegalStateException: if the underlying scope is not currently active

public Object get(String name, ObjectFactory<?> objectFactory)

Return the object with the given name from the underlying scope, creating it if not found in the underlying storage mechanism.

This is the central operation of a Scope, and the only operation that is absolutely required.

Parameters

name:String: the name of the object to retrieve
objectFactory:ObjectFactory<?>: the ObjectFactory to use to create the scoped object if it is not present in the underlying storage mechanism

Returns:Object

the desired object (never null)

Exceptions

IllegalStateException:: if the underlying scope is not currently active

getConversationId back to summary

getConversationId	back to summary
public String getConversationId() Return the conversation ID for the current underlying scope, if any. 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 return `null` in an implementation of this method if the underlying storage mechanism has no obvious candidate for such an ID. Returns:String the conversation ID, or `null` if there is no conversation ID for the current scope Annotations @Nullable Exceptions IllegalStateException: if the underlying scope is not currently active

public String getConversationId()

Return the conversation ID for the current underlying scope, if any.

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 return null in an implementation of this method if the underlying storage mechanism has no obvious candidate for such an ID.

Returns:String

the conversation ID, or null if there is no conversation ID for the current scope

Annotations

@Nullable

Exceptions

IllegalStateException:: if the underlying scope is not currently active

registerDestructionCallback back to summary

registerDestructionCallback	back to summary
public void registerDestructionCallback(String name, Runnable callback) 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). 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 `remove(String)` method, any registered destruction callback should be removed as well, assuming that the removed object will be reused or manually destroyed. Parameters name:String the name of the object to execute the destruction callback for callback:Runnable 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. Exceptions IllegalStateException: if the underlying scope is not currently active See Also `org.springframework.beans.factory.DisposableBean`, `org.springframework.beans.factory.support.AbstractBeanDefinition#getDestroyMethodName()`, `DestructionAwareBeanPostProcessor`

public void registerDestructionCallback(String name, Runnable callback)

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).

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 remove(String) method, any registered destruction callback should be removed as well, assuming that the removed object will be reused or manually destroyed.

Parameters

name:String: the name of the object to execute the destruction callback for
callback:Runnable: 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.

Exceptions

IllegalStateException:: if the underlying scope is not currently active

remove back to summary

remove	back to summary
public Object remove(String name) Remove the object with the given `name` from the underlying scope. Returns `null` if no object was found; otherwise returns the removed `Object`. 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. Parameters name:String the name of the object to remove Returns:Object the removed object, or `null` if no object was present Annotations @Nullable Exceptions IllegalStateException: if the underlying scope is not currently active See Also `registerDestructionCallback`

public Object remove(String name)

Remove the object with the given name from the underlying scope.

Returns null if no object was found; otherwise returns the removed Object.

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.

Parameters

name:String: the name of the object to remove

Returns:Object

the removed object, or null if no object was present

Annotations

@Nullable

Exceptions

IllegalStateException:: if the underlying scope is not currently active

See Also

registerDestructionCallback

resolveContextualObject back to summary

resolveContextualObject	back to summary
public Object resolveContextualObject(String key) Resolve the contextual object for the given key, if any. E.g. the HttpServletRequest object for key "request". Parameters key:String the contextual key Returns:Object the corresponding object, or `null` if none found Annotations @Nullable Exceptions IllegalStateException: if the underlying scope is not currently active

public Object resolveContextualObject(String key)

Resolve the contextual object for the given key, if any. E.g. the HttpServletRequest object for key "request".

Parameters

key:String: the contextual key

Returns:Object

the corresponding object, or null if none found

Annotations

@Nullable

Exceptions

IllegalStateException:: if the underlying scope is not currently active

public Interface Scope

Method Summary

Method Detail