/*
* Copyright (c) 2011, 2013, 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 com.sun.xml.internal.ws.api.server;
import com.sun.xml.internal.ws.server.WSEndpointImpl;
import java.util.HashSet;
import java.util.Set;
import com.sun.org.glassfish.external.amx.AMXGlassfish;
import com.sun.org.glassfish.external.amx.MBeanListener;
import com.sun.org.glassfish.gmbal.ManagedObjectManager;
/**
* The lazy provider is intended to defer Gmbal API calls until there is a JMX connection. The provider is scope
* (environment) aware and behaves accordingly to actual scope. The default behaviour does not defers Gmbal API calls.
*
* There are two kind of method allowing registration of an object as a listener. One is for {@code WSEndpointImpl}
* instances (implementing {@code WSEndpointScopeChangeListener}) and the other is for arbitrary objects
* (implementing {@code DefaultScopeChangeListener}) that want to be notified about scope changes. The distinction is made
* because of the fact that endpoints should be registered first and other objects (e.g. dependants on endpoints) must
* be registered after all the endpoints are processed so no inconsistency is present.
*
* Glassfish:
* {@link WebServicesContainer} is one of two classes for which a {@link ManagedObjectManager} instance (see Gmbal API)
* is created when a webservice application is deployed into the Glassfish. For the purpose of postponing Gmbal API calls
* the {@code WebServicesContainer} extends {@link MBeanListener.CallbackImpl} so it can register itself as a listener of
* {@link AMXGlassfish} and receive a notification about a connection of a JMX client to the Glassfish server (see
* {@code WebServicesContainer#postConstruct} for registration details). The moment the JMX client is connected a notification
* is sent to the listeners of {@code AMXGlassfish}. When this event is received by {@code WebServiceContainer} (see the
* callback method {@code mbeanRegistered}) a {@code ManagedObjectManager} instance is created and no further deferring
* of Gmbal API calls is needed.
*
* Metro/JAX-WS:
* The situation in Metro/JAX-WS is slightly different from the one described above. Metro/JAX-WS can be used as standalone
* libraries (outside of Glassfish) so no notification from the Glassfish server can be expected in this case. This leads
* to a situation when Metro/JAX-WS has to be aware of context in which it is used and acts appropriately. There are 3
* scopes an application using Metro/JAX-WS can be in: {@code STANDALONE}, {@code GLASSFISH_NO_JMX}, {@code GLASSFISH_JMX}
* ({@link LazyMOMProvider#scope}). The default scope is {@code STANDALONE} and all Gmbal API calls are invoked as they
* are requested. The other two scopes are applied only when an application is deployed into a Glassfish server. The
* {@code GLASSFISH_NO_JMX} is set at the moment the application is deployed (see below) and its purpose is to defer Gmbal
* API calls for as long as possible. For some classes e.g. {@code ManagedObjectManager} proxy classes were introduced to
* avoid the necessity of creating the real Gmbal objects but if a method is invoked on these proxies the creation of real
* Gmbal objects is forced even in this scope. The {@code GLASSFISH_JMX} scope is set when a JMX client is connected to
* the Glassfish server and it processes Gmbal API calls without deferring (as if the application was in the
* {@code STANDALONE} scope). The entry point for postponing the Gmbal API calls / creating Gmbal objects in Metro/JAX-WS
* is {@link LazyMOMProvider}. This class is capable of receiving notifications from the Glassfish server
* ({@code LazyMOMProvider.initMOMForScope}) about the scope change and it also spread this information to its listeners.
* The listeners of {@code LazyMOMProvider} are of two kinds: {@link LazyMOMProvider.WSEndpointScopeChangeListener} and
* {@link LazyMOMProvider.DefaultScopeChangeListener}. Extensions of {@link WSEndpoint} (e.g. {@link WSEndpointImpl})
* should implement the {@code LazyMOMProvider.WSEndpointScopeChangeListener} and register themselves as endpoint listeners
* of {@code LazyMOMProvider}. Other classes should implement the latter mentioned interface and register themselves as
* a non-endpoint listener. The differences between these two kind of listeners are described in {@code LazyMOMProvider}
* class comment. An implementation of {@code LazyMOMProvider.DefaultScopeChangeListener} is provided in Metro
* ({@link WSEndpointCollectionBasedMOMListener}). As mentioned above this listener register itself as a non-endpoint
* listener of {@code LazyMOMProvider} ({@code WSEndpointCollectionBasedMOMListener.init}). An instance of this class is
* used in these factories: {@link SessionManager}, {@link NonceManager} and {@link SequenceManagerFactory}.
* {@code SessionManager}, {@code NonceManager}, {@code PersistentSequenceManager} and {@code InVmSequenceManager} also
* (indirectly) implement {@link MOMRegistrationAware} for providing information whether a manager is registered at
* {@code ManagedObjectManager} or not. Registration of a manager at {@code ManagedObjectManager} can be processed directly
* (if {@code WSEndpointCollectionBasedMOMListener.canRegisterAtMOM} returns {@code true}) via
* {@code WSEndpointCollectionBasedMOMListener.registerAtMOM} or is deferred by putting the manager into
* {@code WSEndpointCollectionBasedMOMListener.registrationAwareMap}. Managers stored in for deferred registration are
* processed at the moment the {@code LazyMOMProvider} notifies the {@code WSEndpointCollectionBasedMOMListener} about
* the scope change.
* The mentioned postponing of Gmbal API calls applies only to the server side of the webservice application.
*/
public enum LazyMOMProvider {
INSTANCE;
/**
* Possible scopes (environments) in which the provider (and object associated with it) could be in.
* Default scope is STANDALONE - applied during initialization of classes. For now, only possible scope change for a
* object can be in this direction: STANDALONE -> GLASSFISH_NO_JMX -> GLASSFISH_JMX.
*/
public static enum Scope {
//** Default scope where lazy flag is not applied and all Gmbal API calls are processed immediately. */
STANDALONE,
/** In this scope almost all Gmbal API call are deferred until a JMX connection to a Glassfish server is created */
GLASSFISH_NO_JMX,
/** Same as STANDALONE. Gmbal API calls are processed immediately. */
GLASSFISH_JMX
}
/**
* Interface for all object that want to be notified about scope change, introducing required methods.
*/
public static interface ScopeChangeListener {
void scopeChanged(Scope scope);
}
/**
* Default interface for all object that want to be notified about scope change. This interface should not be
* implemented directly.
*/
public static interface DefaultScopeChangeListener extends ScopeChangeListener {
}
/**
* Interface used for distinguishing between a registration of a WSEndpointImpl rather than of other classes.
* Webservice Endpoints should get a notification about scope change sooner than the rest of the registered listeners
* (there is a possibility that other listeners are dependant on Webservice Endpoints).
*/
public static interface WSEndpointScopeChangeListener extends ScopeChangeListener {
}
private final Set<WSEndpointScopeChangeListener> endpointsWaitingForMOM = new HashSet<WSEndpointScopeChangeListener>();
private final Set<DefaultScopeChangeListener> listeners = new HashSet<DefaultScopeChangeListener>();
private volatile Scope scope = Scope.STANDALONE;
/**
* Initializes this provider with a given scope. If the given scope is different than the one this provider is
* currently in and the transition between scopes is valid then a event is fired to all registered listeners.
*
* @param scope a scope to initialize this provider with
*/
public void initMOMForScope(LazyMOMProvider.Scope scope) {
// cannot go backwards between scopes, for possible scope changes see #Scope
if ((this.scope == Scope.GLASSFISH_JMX)
|| (scope == Scope.STANDALONE && (this.scope == Scope.GLASSFISH_JMX || this.scope == Scope.GLASSFISH_NO_JMX))
|| this.scope == scope) {
return;
}
this.scope = scope;
fireScopeChanged();
}
/**
* Notifies the registered listeners about the scope change.
*/
private void fireScopeChanged() {
for (ScopeChangeListener wsEndpoint : endpointsWaitingForMOM) {
wsEndpoint.scopeChanged(this.scope);
}
for (ScopeChangeListener listener : listeners) {
listener.scopeChanged(this.scope);
}
}
/**
* Registers the given object as a listener.
*
* @param listener a listener to be registered
*/
public void registerListener(DefaultScopeChangeListener listener) {
listeners.add(listener);
if (!isProviderInDefaultScope()) {
listener.scopeChanged(this.scope);
}
}
/**
* Returns {@code true} if this provider is in the default scope.
*
* @return {@code true} if this provider is in the default scope,
* {@code false} otherwise
*/
private boolean isProviderInDefaultScope() {
return this.scope == Scope.STANDALONE;
}
public Scope getScope() {
return scope;
}
/**
* Registers a Webservice Endpoint as a listener.
* Webservice Endpoints should rather register through this method than through LazyMOMProvider#registerListener
* because generally they need to be notified sooner than arbitrary listener (i.e. object that is dependant on
* Webservice Endpoint)
*
* @param wsEndpoint a Webservice Endpoint to be registered
*/
public void registerEndpoint(WSEndpointScopeChangeListener wsEndpoint) {
endpointsWaitingForMOM.add(wsEndpoint);
if (!isProviderInDefaultScope()) {
wsEndpoint.scopeChanged(this.scope);
}
}
/**
* Unregisters a Webservice Endpoint from the list of listeners.
*
* @param wsEndpoint a Webservice Endpoint to be unregistered
*/
public void unregisterEndpoint(WSEndpointScopeChangeListener wsEndpoint) {
endpointsWaitingForMOM.remove(wsEndpoint);
}
}