java.beans.beancontext

Interface BeanContextServiceProvider

Known Implementing Classes:
BeanContextServicesSupport.BCSSProxyServiceProvider

public interface BeanContextServiceProvider

An actual factory for services.

It is the BeanContextServiceProvider's responsibility to register itself with whatever BeanContextServices object it wishes to provide services through using the addService() method.

If for some reason it can no longer provide services for a particular class, this class must invoke BeanContextServices.revokeService(serviceClass,this,true) for all the places it has registered the service.

Since:
JDK1.2

Method Summary

Iterator<E>
getCurrentServiceSelectors(BeanContextServices services, Class<T> serviceClass)
Get a list of valid service selectors for the specified service class.
Object
getService(BeanContextServices services, Object requestor, Class<T> serviceClass, Object serviceSelector)
Get a service.
void
releaseService(BeanContextServices services, Object requestor, Object service)
Release the service.

Method Details

getCurrentServiceSelectors

public Iterator<E> getCurrentServiceSelectors(BeanContextServices services,
                                           Class<T> serviceClass)
Get a list of valid service selectors for the specified service class. This method is called from BeanContextServices.getCurrentServiceSelectors().

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:
services - the BeanContextServices that wants to get the service selectors. Only weak references to this will be retained, and it will never be changed, only queried in a read-only manner.
serviceClass - the service class to get selectors for.
Returns:
a list of valid service selectors for the service class, or null.

getService

public Object getService(BeanContextServices services,
                         Object requestor,
                         Class<T> serviceClass,
                         Object serviceSelector)
Get a service. Called from BeanContextServices.getService().

If the requested service class is not available, or if this BeanContextServiceProvider chooses not honor the request for some reason, then this method will return null. This method may throw unchecked exceptions, so watch out.

Parameters:
services - the BeanContextServices that wants to get the service. 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.
Returns:
an instance of serviceClass (such that instanceof serviceClass is true), or null.

releaseService

public void releaseService(BeanContextServices services,
                           Object requestor,
                           Object service)
Release the service.

Called by BeanContextServices.releaseService().

Most BeanContextServiceProviders won't have to do anything here.

Parameters:
services - the BeanContextServices that wants to release the service. Only weak references to this will be retained, and it will never be changed, only queried in a read-only manner.
requestor - the original requestor of the service.
service - the service to relinquish

java.beans.beancontext.BeanContextServiceProvider Copyright (C) 1999 Free Software Foundation, Inc. This file is part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU Classpath is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.