java.beans.beancontext
public interface BeanContextServices extends BeanContext, BeanContextServicesListener
BeanContext
to provide services to its children.
Since: 1.2
UNKNOWN: it is unclear whether a BeanContextServices
should delegate unhandled requests to parents. I assume so.
Method Summary | |
---|---|
void | addBeanContextServicesListener(BeanContextServicesListener listener)
Add a listener on all adds and removes of services. |
boolean | addService(Class serviceClass, BeanContextServiceProvider provider)
Register a service to make it available to others.
|
Iterator | getCurrentServiceClasses()
Get a list of all service classes supported.
|
Iterator | getCurrentServiceSelectors(Class serviceClass)
Get a list of valid service selectors for the specified service class.
|
Object | getService(BeanContextChild requestorChild, Object requestor, Class serviceClass, Object serviceSelector, BeanContextServiceRevokedListener listener)
Get a service from this BeanContextServices .
|
boolean | hasService(Class serviceClass)
Tell whether the specified service class is available.
|
void | releaseService(BeanContextChild requestorChild, Object requestor, Object service)
Release your copy of this service.
|
void | removeBeanContextServicesListener(BeanContextServicesListener listener)
Remove a listener on all adds and removes of services. |
void | revokeService(Class serviceClass, BeanContextServiceProvider provider, boolean revokeNow)
Make it so that no one else can use this service.
|
Parameters: listener the listener to add.
Parameters: serviceClass the service class. provider the factory that will actually provide the service.
Returns: whether the service was added or not.
This method must synchronize on
BeanContext.globalHierarchyLock
.
Returns: a list of all service classes supported.
See Also: globalHierarchyLock
If the specified service class does not have a finite number of
valid service selectors, it should return null
.
If it takes a general Integer
parameter, for
example, you may as well return null
or the poor
soul who called this method will be iterating all day.
If it has no valid service selectors, it should still return an empty
Iterator
.
Parameters: serviceClass the service class to get selectors for.
Returns: a list of valid service selectors for the service
class, or null
.
BeanContextServices
.
The specified listener will be registered to receive a revocation notice for the specified serviceClass. One notification per service class per requestor object will be sent.
The listener will be unregistered when all services that were obtained by that requestor for that service class are released.
If the requested service class is not available, or if this
BeanContextServices
object chooses not honor the
request because the service class has been revoked or for some
other reason, then this method will return null
.
This method may throw unchecked exceptions, so watch out.
Parameters: requestorChild the BeanContextChild
associated with the requestor. Typically this will be
the same as the requestor itself, but since any
Object
, even one outside the hierarchy, may
make a request, this parameter is necessary. Only weak
references to this will be retained, and it will never
be changed, only queried in a read-only manner. requestor the actual requestor of the service. Only
weak references to this will be retained, and it will
never be changed, only queried in a read-only manner. serviceClass the Class
of the service being
requested. serviceSelector a parameter to customize the service
returned with. listener a listener that will be notified if the service
being requested is revoked.
Returns: an instance of serviceClass
(such that
instanceof
serviceClass is true), or
null
.
UNKNOWN: it is not specified what happens when two subsequent
calls are made to getService()
with the
same requestor object and service class but different
listeners. Which listener is to be notified?
true
.
Parameters: serviceClass the service class to check on.
Returns: whether the specified service class is available.
If all copies of the service's class have been relinquished by
the requestor, the BeanContextServiceRevokedListener
previously registered by getService()
will be
unregistered.
Parameters: requestorChild the original BeanContextChild
requesting the service. requestor the original requestor of the service. service the service to relinquish
See Also: getService
Parameters: listener the listener to add.
UNKNOWN: it is not certain whether this should remove this
listener if it was specified in
getService()
.
If revokeNow
is false
, the only
effect of this method is to make all subsequent calls to
getService()
on this service class fail.
If it is true
, a message is also sent out to all
listeners on the service and all references to it are released.
Parameters: serviceClass the service class to revoke. provider the service provider providing the service class. revokeNow whether to release all current references to the service.