/* * Copyright (c) 1998, 2004, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation.  Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code 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 * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package java.beans.beancontext; import java.util.Iterator; /** * <p> * One of the primary functions of a BeanContext is to act a as rendezvous * between JavaBeans, and BeanContextServiceProviders. * </p> * <p> * A JavaBean nested within a BeanContext, may ask that BeanContext to * provide an instance of a "service", based upon a reference to a Java * Class object that represents that service. * </p> * <p> * If such a service has been registered with the context, or one of its * nesting context's, in the case where a context delegate to its context * to satisfy a service request, then the BeanContextServiceProvider associated with * the service is asked to provide an instance of that service. * </p> * <p> * The ServcieProvider may always return the same instance, or it may * construct a new instance for each request. * </p> */ public interface BeanContextServiceProvider {    /**    * Invoked by <code>BeanContextServices</code>, this method    * requests an instance of a    * service from this <code>BeanContextServiceProvider</code>.    *    * @param bcs The <code>BeanContextServices</code> associated with this    * particular request. This parameter enables the    * <code>BeanContextServiceProvider</code> to distinguish service    * requests from multiple sources.    *    * @param requestor          The object requesting the service    *    * @param serviceClass       The service requested    *    * @param serviceSelector the service dependent parameter    * for a particular service, or <code>null</code> if not applicable.    *    * @return a reference to the requested service    */    Object getService(BeanContextServices bcs, Object requestor, Class serviceClass, Object serviceSelector);     /**     * Invoked by <code>BeanContextServices</code>,     * this method releases a nested <code>BeanContextChild</code>'s     * (or any arbitrary object associated with a     * <code>BeanContextChild</code>) reference to the specified service.     *     * @param bcs the <code>BeanContextServices</code> associated with this     * particular release request     *     * @param requestor the object requesting the service to be released     *     * @param service the service that is to be released     */    public void releaseService(BeanContextServices bcs, Object requestor, Object service);     /**     * Invoked by <code>BeanContextServices</code>, this method     * gets the current service selectors for the specified service.     * A service selector is a service specific parameter,     * typical examples of which could include: a     * parameter to a constructor for the service implementation class,     * a value for a particular service's property, or a key into a     * map of existing implementations.     *     * @param bcs           the <code>BeanContextServices</code> for this request     * @param serviceClass  the specified service     * @return   the current service selectors for the specified serviceClass     */    Iterator getCurrentServiceSelectors(BeanContextServices bcs, Class serviceClass);}