java.beans.beancontext
Interface BeanContextServices

All Superinterfaces:
BeanContext, BeanContextChild, BeanContextServiceRevokedListener, BeanContextServicesListener, Collection, DesignMode, EventListener, Iterable, Visibility
All Known Implementing Classes:
BeanContextServicesSupport

public interface BeanContextServices
extends BeanContext, BeanContextServicesListener

Allows a BeanContext to provide services to its children.

Since:
1.2

Field Summary
 
Fields inherited from interface java.beans.beancontext.BeanContext
globalHierarchyLock
 
Fields inherited from interface java.beans.DesignMode
PROPERTYNAME
 
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.
 
Methods inherited from interface java.beans.beancontext.BeanContext
addBeanContextMembershipListener, getResource, getResourceAsStream, instantiateChild, removeBeanContextMembershipListener
 
Methods inherited from interface java.util.Collection
add, addAll, clear, contains, containsAll, equals, hashCode, isEmpty, iterator, remove, removeAll, retainAll, size, toArray, toArray
 
Methods inherited from interface java.beans.beancontext.BeanContextChild
addPropertyChangeListener, addVetoableChangeListener, getBeanContext, removePropertyChangeListener, removeVetoableChangeListener, setBeanContext
 
Methods inherited from interface java.beans.Visibility
avoidingGui, dontUseGui, needsGui, okToUseGui
 
Methods inherited from interface java.beans.DesignMode
isDesignTime, setDesignTime
 
Methods inherited from interface java.beans.beancontext.BeanContextServicesListener
serviceAvailable
 
Methods inherited from interface java.beans.beancontext.BeanContextServiceRevokedListener
serviceRevoked
 

Method Detail

addService

boolean addService(Class serviceClass,
                   BeanContextServiceProvider provider)
Register a service to make it available to others. This class may refuse to add the service based on whatever information it can gather, including whether the service provider is trusted.

Parameters:
serviceClass - the service class.
provider - the factory that will actually provide the service.
Returns:
whether the service was added or not.

revokeService

void revokeService(Class serviceClass,
                   BeanContextServiceProvider provider,
                   boolean revokeNow)
Make it so that no one else can use this service.

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.

releaseService

void releaseService(BeanContextChild requestorChild,
                    Object requestor,
                    Object service)
Release your copy of this service.

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(java.beans.beancontext.BeanContextChild,java.lang.Object,java.lang.Class,java.lang.Object,java.beans.beancontext.BeanContextServiceRevokedListener)

getService

Object getService(BeanContextChild requestorChild,
                  Object requestor,
                  Class serviceClass,
                  Object serviceSelector,
                  BeanContextServiceRevokedListener listener)
                  throws TooManyListenersException
Get a service from this 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.
Throws:
TooManyListenersException

getCurrentServiceClasses

Iterator getCurrentServiceClasses()
Get a list of all service classes supported.

This method must synchronize on BeanContext.globalHierarchyLock.

Returns:
a list of all service classes supported.
See Also:
BeanContext.globalHierarchyLock

getCurrentServiceSelectors

Iterator getCurrentServiceSelectors(Class serviceClass)
Get a list of valid service selectors for the specified service class.

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.

hasService

boolean hasService(Class serviceClass)
Tell whether the specified service class is available. Iff getService() could return a non-null value for the specified service, this method will return true.

Parameters:
serviceClass - the service class to check on.
Returns:
whether the specified service class is available.

addBeanContextServicesListener

void addBeanContextServicesListener(BeanContextServicesListener listener)
Add a listener on all adds and removes of services.

Parameters:
listener - the listener to add.

removeBeanContextServicesListener

void removeBeanContextServicesListener(BeanContextServicesListener listener)
Remove a listener on all adds and removes of services.

Parameters:
listener - the listener to add.