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/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

package javaa.beans.beancontext;

import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.net.URL;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Locale;

import javaa.beans.Beans;
import javaa.beans.PropertyChangeEvent;
import javaa.beans.PropertyChangeListener;
import javaa.beans.PropertyVetoException;
import javaa.beans.VetoableChangeListener;
import javaa.beans.Visibility;

import org.apache.harmony.beans.internal.nls.Messages;

/**
 * This support class implements BeanContext interface. 
 * This class can be used directly, or be a super class of your class,
 * or be a delegate of your implementation that needs to support 
 * BeanContext interface.
 * 
 */
public class BeanContextSupport extends BeanContextChildSupport implements
        BeanContext, PropertyChangeListener, VetoableChangeListener,
        Serializable {

    /**
     * Every child of context is companied with a BCSChild
     * instance. It can hold implementation specific information about
     * each child.
     * 

* This class holds references of the child and its peer if there is one.

* */ protected class BCSChild implements Serializable { private static final long serialVersionUID = -5815286101609939109L; Object child; Object proxyPeer; BCSChild(Object child, Object proxyPeer) { this.child = child; this.proxyPeer = proxyPeer; } } /** * This implementation wraps an iterator and override * remove() with a noop method. * */ protected static final class BCSIterator implements Iterator { private Iterator backIter; BCSIterator(Iterator backIter) { this.backIter = backIter; } public boolean hasNext() { return backIter.hasNext(); } public Object next() { return backIter.next(); } public void remove() { // no-op } } private static final long serialVersionUID = -4879613978649577204L; //J2SE 1.4.2 /** * A list of registered membership listeners. * All access to this object should be synchronized on itself. */ @SuppressWarnings("unchecked") transient protected ArrayList bcmListeners; /** * A map of children - key is child instance, value is BCSChild instance. * All access to this object should be synchronized on itself. */ @SuppressWarnings("unchecked") transient protected HashMap children; transient private boolean serializing; transient private boolean inNeedsGui; transient private PropertyChangeListener nonSerPCL; private int serializable; /** * The locale of this context. */ protected Locale locale; /** * A flag indicating whether this context is allowed to use GUI. */ protected boolean okToUseGui; /** * A flag indicating whether this context is in design mode. */ protected boolean designTime; /** * Constructs a standload BeanContextSupport. */ public BeanContextSupport() { this(null, Locale.getDefault(), false, true); } /** * Constructs a BeanContextSupport which is a delegate * of the given peer. * * @param peer the peer of this context */ public BeanContextSupport(BeanContext peer) { this(peer, Locale.getDefault(), false, true); } /** * Constructs a BeanContextSupport which is a delegate * of the given peer. * * @param peer the peer of this context * @param locale the locale of this context */ public BeanContextSupport(BeanContext peer, Locale locale) { this(peer, locale, false, true); } /** * Constructs a BeanContextSupport which is a delegate * of the given peer. * * @param peer the peer of this context * @param locale the locale of this context * @param designTime whether in design mode or not */ public BeanContextSupport(BeanContext peer, Locale locale, boolean designTime) { this(peer, locale, designTime, true); } /** * Constructs a BeanContextSupport which is a delegate * of the given peer. * * @param peer the peer of this context * @param locale the locale of this context * @param designTime whether in design mode or not * @param okToUseGui whether GUI is usable or not */ public BeanContextSupport(BeanContext peer, Locale locale, boolean designTime, boolean okToUseGui) { super(peer); if (locale == null) { locale = Locale.getDefault(); } this.locale = locale; this.designTime = designTime; this.okToUseGui = okToUseGui; initialize(); } /** * Add a child to this context. *

* If the child already exists in this context, simply returns false. * Otherwise, it is validated by calling validatePendingAdd(). * If the add is valid, the child and its proxy (if the child implements * BeanContextProxy) is then added, and setBeanContext() * is called on it (if the child implements BeanContextChild * or it has a proxy). Last, the childJustAddedHook() is * called and all registered BeanContextMembershipListeners * are notified.

* * @param child the child to add * @return true if the child is added to this context; otherwise false * @throws IllegalStateException if the child is not valid to add * @see java.util.Collection#add(java.lang.Object) */ @SuppressWarnings("unchecked") public boolean add(Object child) { if (child == null) { throw new IllegalArgumentException(Messages.getString("beans.67")); } BeanContextChild proxy = null; synchronized (globalHierarchyLock) { // check existence if (contains(child)) { return false; } // check serializing state if (serializing) { throw new IllegalStateException( Messages.getString("beans.68")); } // validate boolean valid = validatePendingAdd(child); if (!valid) { throw new IllegalStateException( Messages.getString("beans.69")); } // find the proxy, if there's one if (child instanceof BeanContextProxy) { proxy = ((BeanContextProxy) child).getBeanContextProxy(); if (proxy == null) { throw new NullPointerException( Messages.getString("beans.6A")); } } BeanContextChild beanContextChild = getChildBeanContextChild(child); // add to children BCSChild childBCSC = null, proxyBCSC = null; synchronized (children) { childBCSC = createBCSChild(child, proxy); children.put(child, childBCSC); if (proxy != null) { proxyBCSC = createBCSChild(proxy, child); children.put(proxy, proxyBCSC); } } // set child's beanContext property if (beanContextChild != null) { try { beanContextChild.setBeanContext(getBeanContextPeer()); } catch (PropertyVetoException e) { synchronized (children) { children.remove(child); if (proxy != null) { children.remove(proxy); } } throw new IllegalStateException( Messages.getString("beans.6B")); } // ensure no duplicate listener beanContextChild.removePropertyChangeListener("beanContext", nonSerPCL); // listen to child's beanContext change beanContextChild.addPropertyChangeListener("beanContext", nonSerPCL); } // trigger hook synchronized (child) { addSerializable(childBCSC); childJustAddedHook(child, childBCSC); } if (proxy != null) { synchronized (proxy) { addSerializable(proxyBCSC); childJustAddedHook(proxy, proxyBCSC); } } } // notify listeners fireChildrenAdded(new BeanContextMembershipEvent(getBeanContextPeer(), proxy == null ? new Object[] { child } : new Object[] { child, proxy })); return true; } /** * This method is unsupported, throws UnsupportedOperationException. * * @see java.util.Collection#addAll(java.util.Collection) */ public boolean addAll(Collection collection) { throw new UnsupportedOperationException(); } /* (non-Javadoc) * @see java.beans.beancontext.BeanContext#addBeanContextMembershipListener(java.beans.beancontext.BeanContextMembershipListener) */ public void addBeanContextMembershipListener( BeanContextMembershipListener listener) { if (listener == null) { throw new NullPointerException(); } synchronized (bcmListeners) { if (!bcmListeners.contains(listener)) { bcmListeners.add(listener); } } } /* (non-Javadoc) * @see java.beans.Visibility#avoidingGui() */ public boolean avoidingGui() { // Avoiding GUI means that // GUI is needed but not allowed to use at this time return (needsGui() && !this.okToUseGui); } /** * Returns an iterator of all BCSChild instances, * with remove() disabled. * * @return an iterator of all BCSChild instances */ protected Iterator bcsChildren() { synchronized (children) { return new BCSIterator(children.values().iterator()); } } /** * This method is called by readObject() after * defaultReadObject() and before deserializing any * children or listeners. Subclass can insert its specific * deserialization behavior by overrideing this method. *

* The default implementation does nothing.

* * @param ois the object input stream * @throws IOException * @throws ClassNotFoundException */ protected void bcsPreDeserializationHook(ObjectInputStream ois) throws IOException, ClassNotFoundException { // to be overridden } /** * This method is called by writeObject() after * defaultWriteObject() and before serializing any * children or listeners. Subclass can insert its specific * serialization behavior by overrideing this method. *

* The default implementation does nothing.

* * @param oos the object output stream * @throws IOException */ protected void bcsPreSerializationHook(ObjectOutputStream oos) throws IOException { // to be overridden } /** * This method is called during deserialization everytime a child is read. *

* The default implementation does nothing.

* * @param child the child just deserialized * @param bcsChild the BCSChild just deserialized */ protected void childDeserializedHook(Object child, BCSChild bcsChild) { // to be overridden } /** * This method is called everytime a child is added to this context. * This method is called with child synchronized. *

* The default implementation does nothing.

* * @param child the child just added * @param bcsChild the BCSChild just added */ protected void childJustAddedHook(Object child, BCSChild bcsChild) { // to be overridden } /** * This method is called everytime a child is removed from this context. * This method is called with child synchronized. *

* The default implementation does nothing.

* * @param child the child just removed * @param bcsChild the BCSChild just removed */ protected void childJustRemovedHook(Object child, BCSChild bcsChild) { // to be overridden } /** * Compares if two classes are equal or their class names are equal. * * @param clz1 a class * @param clz2 another class * @return true if two class objects are equal or their class names are equal. */ protected static final boolean classEquals(Class clz1, Class clz2) { if (clz1 == null || clz2 == null) { throw new NullPointerException(); } return clz1 == clz2 || clz1.getName().equals(clz2.getName()); } /** * This method is unsupported, throws UnsupportedOperationException. * * @see java.util.Collection#clear() */ public void clear() { throw new UnsupportedOperationException(); } /** * Returns true if the given object is a child of this context. * * @param child the object to test * @return true if the given object is a child of this context * @see java.util.Collection#contains(java.lang.Object) */ public boolean contains(Object child) { synchronized (children) { return children.containsKey(child); } } /** * Returns true if given objects are children of this context. * * @param collection a collection of objects * @return true if given objects are children of this context * @see java.util.Collection#containsAll(java.util.Collection) */ @SuppressWarnings("unchecked") public boolean containsAll(Collection collection) { synchronized (children) { return children.keySet().containsAll(collection); } } /** * Returns true if the given object is a child of this context. * * @param child the object to test * @return true if the given object is a child of this context */ public boolean containsKey(Object child) { synchronized (children) { return children.containsKey(child); } } /** * Returns an array containing all children of this context. * * @return an array containing all children of this context */ protected final Object[] copyChildren() { synchronized (children) { return children.keySet().toArray(); } } /** * Creates a BCSChild object to company the given child. * * @param child the child * @param proxyPeer the proxy peer of the child if there is one * @return a BCSChild object to company the given child */ protected BCSChild createBCSChild(Object child, Object proxyPeer) { return new BCSChild(child, proxyPeer); } /** * Deserialize a collection. *

* First read a int indicating of number of rest objects, * then read the objects one by one.

* * @param ois the stream where the collection is read from * @param collection the collection to hold read objects * @throws IOException if I/O exception occurs * @throws ClassNotFoundException if class of any read object is not found */ @SuppressWarnings("unchecked") protected final void deserialize(ObjectInputStream ois, Collection collection) throws IOException, ClassNotFoundException { int size = ois.readInt(); for (int i = 0; i < size; i++) { collection.add(ois.readObject()); } } /* (non-Javadoc) * @see java.beans.Visibility#dontUseGui() */ public void dontUseGui() { okToUseGui = false; } /** * Notifies registered BeanContextMembershipListeners that * a new child has been added. * * @param event the BeanContextMembershipEvent */ protected final void fireChildrenAdded(BeanContextMembershipEvent event) { Object listeners[]; synchronized (bcmListeners) { listeners = bcmListeners.toArray(); } for (int i = 0; i < listeners.length; i++) { BeanContextMembershipListener l = (BeanContextMembershipListener) listeners[i]; l.childrenAdded(event); } } /** * Notifies registered BeanContextMembershipListeners that * a child has been removed. * * @param event the BeanContextMembershipEvent */ protected final void fireChildrenRemoved(BeanContextMembershipEvent event) { Object listeners[]; synchronized (bcmListeners) { listeners = bcmListeners.toArray(); } for (int i = 0; i < listeners.length; i++) { BeanContextMembershipListener l = (BeanContextMembershipListener) listeners[i]; l.childrenRemoved(event); } } /** * Returns the peer of this context casted as BeanContext. * * @return the peer of this context casted as BeanContext */ public BeanContext getBeanContextPeer() { return (BeanContext) beanContextChildPeer; } /** * Returns the BeanContextChild related with the given child. *

* If the child implements BeanContextChild, it is returned. * If the child implements BeanContextProxy, the proxy is returned. * Otherwise, null is returned.

* * @param child a child * @return the BeanContextChild related with the given child * @throws IllegalStateException if the child implements both BeanContextChild and BeanContextProxy */ protected static final BeanContextChild getChildBeanContextChild( Object child) { if (child instanceof BeanContextChild) { if (child instanceof BeanContextProxy) { throw new IllegalArgumentException( Messages.getString("beans.6C")); } return (BeanContextChild) child; } if (child instanceof BeanContextProxy) { if (child instanceof BeanContextChild) { throw new IllegalArgumentException( Messages.getString("beans.6C")); } return ((BeanContextProxy) child).getBeanContextProxy(); } return null; } /** * Returns the given child casted to BeanContextMembershipListener, * or null if it does not implements the interface. * * @param child a child * @return the given child casted to BeanContextMembershipListener, * or null if it does not implements the interface */ protected static final BeanContextMembershipListener getChildBeanContextMembershipListener( Object child) { if (child instanceof BeanContextMembershipListener) { return (BeanContextMembershipListener) child; } else { return null; } } /** * Returns the given child casted to PropertyChangeListener, * or null if it does not implements the interface. * * @param child a child * @return the given child casted to PropertyChangeListener, * or null if it does not implements the interface */ protected static final PropertyChangeListener getChildPropertyChangeListener( Object child) { if (child instanceof PropertyChangeListener) { return (PropertyChangeListener) child; } else { return null; } } /** * Returns the given child casted to Serializable, * or null if it does not implements the interface. * * @param child a child * @return the given child casted to Serializable, * or null if it does not implements the interface */ protected static final Serializable getChildSerializable(Object child) { if (child instanceof Serializable) { return (Serializable) child; } else { return null; } } /** * Returns the given child casted to VetoableChangeListener, * or null if it does not implements the interface. * * @param child a child * @return the given child casted to VetoableChangeListener, * or null if it does not implements the interface */ protected static final VetoableChangeListener getChildVetoableChangeListener( Object child) { if (child instanceof VetoableChangeListener) { return (VetoableChangeListener) child; } else { return null; } } /** * Returns the given child casted to Visibility, * or null if it does not implements the interface. * * @param child a child * @return the given child casted to Visibility, * or null if it does not implements the interface */ protected static final Visibility getChildVisibility(Object child) { if (child instanceof Visibility) { return (Visibility) child; } else { return null; } } /** * Returns the locale of this context. * * @return the locale of this context */ public Locale getLocale() { return locale; } /* (non-Javadoc) * @see java.beans.beancontext.BeanContext#getResource(java.lang.String, java.beans.beancontext.BeanContextChild) */ public URL getResource(String resourceName, BeanContextChild child) { if (resourceName == null || child == null) { throw new NullPointerException(); } if (!contains(child)) { throw new IllegalArgumentException(Messages.getString("beans.6D")); } return ClassLoader.getSystemResource(resourceName); } /* (non-Javadoc) * @see java.beans.beancontext.BeanContext#getResourceAsStream(java.lang.String, java.beans.beancontext.BeanContextChild) */ public InputStream getResourceAsStream(String resourceName, BeanContextChild child) throws IllegalArgumentException { if (resourceName == null || child == null) { throw new NullPointerException(); } if (!contains(child)) { throw new IllegalArgumentException(Messages.getString("beans.6D")); } return ClassLoader.getSystemResourceAsStream(resourceName); } /** * Initializes all transient fields of this instance, called by * constructors and readObject(). */ protected void initialize() { // init transient fields bcmListeners = new ArrayList(); children = new HashMap(); serializing = false; inNeedsGui = false; nonSerPCL = new PropertyChangeListener() { public void propertyChange(PropertyChangeEvent event) { BeanContextSupport.this.propertyChange(event); } }; } /* (non-Javadoc) * @see java.beans.beancontext.BeanContext#instantiateChild(java.lang.String) */ public Object instantiateChild(String beanName) throws IOException, ClassNotFoundException { return Beans.instantiate(getClass().getClassLoader(), beanName, getBeanContextPeer()); } /* (non-Javadoc) * @see java.beans.DesignMode#isDesignTime() */ public boolean isDesignTime() { return designTime; } /* (non-Javadoc) * @see java.util.Collection#isEmpty() */ public boolean isEmpty() { synchronized (children) { return children.isEmpty(); } } /** * Returns true if this context is currently being serialized * (by another thread). * * @return true if this context is currently being serialized * (by another thread) */ public boolean isSerializing() { return serializing; } /** * Returns an iterator of children of this context, * with remove() disabled. * * @see java.util.Collection#iterator() */ public Iterator iterator() { synchronized (children) { return new BCSIterator(children.keySet().iterator()); } } /** * Returns true if this context or its children needs GUI to work properly. *

* The implementation checks the peer and all the children that implement * Visibility to see if any of their needsGui() * returns true, and if any of the children extends * java.awt.Component.

* * @see javaa.beans.Visibility#needsGui() */ public boolean needsGui() { if (inNeedsGui) { return false; } inNeedsGui = true; try { if (getBeanContextPeer() != this) { if (getBeanContextPeer().needsGui()) { return true; } } Object childs[] = copyChildren(); for (int i = 0; i < childs.length; i++) { Visibility v = getChildVisibility(childs[i]); if (v != null && v.needsGui()) { return true; } } return false; } finally { inNeedsGui = false; } } /* (non-Javadoc) * @see java.beans.Visibility#okToUseGui() */ public void okToUseGui() { okToUseGui = true; } /* (non-Javadoc) * @see java.beans.PropertyChangeListener#propertyChange(java.beans.PropertyChangeEvent) */ public void propertyChange(PropertyChangeEvent event) { if (contains(event.getSource()) && "beanContext".equals(event.getPropertyName()) && event.getOldValue() == getBeanContextPeer()) { remove(event.getSource(), false); } } /** * Deserializes children from the given object input stream. *

* The implementation reads pairs of child object and BCSChild * object according to serializable property. For each pair, * it is added to the children map and the * childDeserializedHook() is called. If the child implements * BeanContextChild, its setBeanContext() is * also called. *

*

* This method is called by readObject() if the context works * standalone. Or if this support object is a delegate of another * BeanContext implementation, then this method should be * called by the peer. Doing this means that derialization can proceed * without any circular dependency problems. * * @param ois * the object input stream * @throws IOException * if I/O exception occurs * @throws ClassNotFoundException * if class of read object is not found */ @SuppressWarnings("unchecked") public final void readChildren(ObjectInputStream ois) throws IOException, ClassNotFoundException { synchronized (children) { for (int i = 0; i < serializable; i++) { Object child = ois.readObject(); BCSChild childBCSC = (BCSChild) ois.readObject(); children.put(child, childBCSC); childDeserializedHook(child, childBCSC); // set child's beanContext property BeanContextChild beanContextChild = getChildBeanContextChild(child); if (beanContextChild != null) { try { beanContextChild.setBeanContext(getBeanContextPeer()); } catch (PropertyVetoException e) { throw new IOException( Messages.getString("beans.6B")); } // ensure no duplicate listener beanContextChild.removePropertyChangeListener( "beanContext", nonSerPCL); // listen to child's beanContext change beanContextChild.addPropertyChangeListener("beanContext", nonSerPCL); } } } } /** * Removes the given child from this context. *

* Delegates to remove(child, true).

* * @param child a child of this context * @return true if the child is removed; or false if it is not a child of this context * @throws IllegalArgumentException if the child is null * @throws IllegalStateException if the child is not valid to remove * @see java.util.Collection#remove(java.lang.Object) */ public boolean remove(Object child) { return remove(child, true); } /** * Removes the given child from this context. *

* If the given child is not a child of this context, simply returns false. * Otherwise, validatePendingRemove() is called. If the * removal is valid, the child's beanContext property is * updated (if required) and the child and its proxy peer (if there is one) * is removed. Last, childJustRemovedHook() is called and * listeners are notified.

* * @param child a child of this context * @param setChildBC whether to call setBeanContext() on the child or not * @return true if the child is removed; or false if it is not a child of this context * @throws IllegalArgumentException if the child is null * @throws IllegalStateException if the child is not valid to remove */ protected boolean remove(Object child, boolean setChildBC) { if (child == null) { throw new IllegalArgumentException(Messages.getString("beans.67")); } Object peer = null; synchronized (globalHierarchyLock) { // check existence if (!contains(child)) { return false; } // check serializing state if (serializing) { throw new IllegalStateException( Messages.getString("beans.68")); } // validate boolean valid = validatePendingRemove(child); if (!valid) { throw new IllegalStateException( Messages.getString("beans.6E")); } // set child's beanContext property BeanContextChild beanContextChild = getChildBeanContextChild(child); if (beanContextChild != null && setChildBC) { // remove listener, first beanContextChild.removePropertyChangeListener("beanContext", nonSerPCL); try { beanContextChild.setBeanContext(null); } catch (PropertyVetoException e) { // rollback the listener change beanContextChild.addPropertyChangeListener("beanContext", nonSerPCL); throw new IllegalStateException( Messages.getString("beans.6B")); } } // remove from children BCSChild childBCSC = null, peerBCSC = null; synchronized (children) { childBCSC = (BCSChild) children.remove(child); peer = childBCSC.proxyPeer; if (peer != null) { peerBCSC = (BCSChild) children.remove(peer); } } // trigger hook synchronized (child) { removeSerializable(childBCSC); childJustRemovedHook(child, childBCSC); } if (peer != null) { synchronized (peer) { removeSerializable(peerBCSC); childJustRemovedHook(peer, peerBCSC); } } } // notify listeners fireChildrenRemoved(new BeanContextMembershipEvent( getBeanContextPeer(), peer == null ? new Object[] { child } : new Object[] { child, peer })); return true; } /** * This method is unsupported, throws UnsupportedOperationException. * * @see java.util.Collection#removeAll(java.util.Collection) */ public boolean removeAll(Collection collection) { throw new UnsupportedOperationException(); } /* (non-Javadoc) * @see java.beans.beancontext.BeanContext#removeBeanContextMembershipListener(java.beans.beancontext.BeanContextMembershipListener) */ public void removeBeanContextMembershipListener( BeanContextMembershipListener listener) { if (listener == null) { throw new NullPointerException(); } synchronized (bcmListeners) { bcmListeners.remove(listener); } } /** * This method is unsupported, throws UnsupportedOperationException. * * @see java.util.Collection#retainAll(java.util.Collection) */ public boolean retainAll(Collection collection) { throw new UnsupportedOperationException(); } /** * Serializes the given collection. *

* First writes a int indicating the number of all * serializable elements (implements Serializable, then * objects are writtern one by one.

* * @param oos the stream where the collection is writtern to * @param collection the collection to serialize * @throws IOException if I/O exception occurs */ protected final void serialize(ObjectOutputStream oos, Collection collection) throws IOException { Object array[] = collection.toArray(); int serCount = 0; for (int i = 0; i < array.length; i++) { if (array[i] instanceof Serializable) { serCount++; } } oos.writeInt(serCount); for (int i = 0; i < array.length; i++) { if (array[i] instanceof Serializable) { oos.writeObject(array[i]); } } } /* (non-Javadoc) * @see java.beans.DesignMode#setDesignTime(boolean) */ public void setDesignTime(boolean designTime) { this.designTime = designTime; } /** * Sets the locale of this context. VetoableChangeListeners * and PropertyChangeListeners are notified. * * @param newLocale the new locale to set * @throws PropertyVetoException if any VetoableChangeListener vetos this change */ public void setLocale(Locale newLocale) throws PropertyVetoException { if (newLocale == null || newLocale == locale) { return; // ignore null locale } PropertyChangeEvent event = new PropertyChangeEvent( beanContextChildPeer, "locale", locale, newLocale); // apply change Locale oldLocale = locale; locale = newLocale; try { // notify vetoable listeners vcSupport.fireVetoableChange(event); } catch (PropertyVetoException e) { // rollback change locale = oldLocale; throw e; } // Notify BeanContext about this change this.pcSupport.firePropertyChange(event); } /** * Returns the number children of this context. * * @return the number children of this context * @see java.util.Collection#size() */ public int size() { synchronized (children) { return children.size(); } } /** * Returns an array of children of this context. * * @return an array of children of this context * @see java.util.Collection#toArray() */ public Object[] toArray() { synchronized (children) { return children.keySet().toArray(); } } /** * Returns an array of children of this context. * * @return an array of children of this context * @see java.util.Collection#toArray(java.lang.Object[]) */ @SuppressWarnings("unchecked") public Object[] toArray(Object[] array) { synchronized (children) { return children.keySet().toArray(array); } } /** * Validates the pending add of child. *

* Default implementation always returns true.

* * @param child the child to be added * @return true if it is valid to add the child */ protected boolean validatePendingAdd(Object child) { // to be overridden return true; } /** * Validates the pending removal of child. *

* Default implementation always returns true.

* * @param child the child to be removed * @return true if it is valid to remove the child */ protected boolean validatePendingRemove(Object child) { // to be overridden return true; } /* (non-Javadoc) * @see java.beans.VetoableChangeListener#vetoableChange(java.beans.PropertyChangeEvent) */ public void vetoableChange(PropertyChangeEvent pce) throws PropertyVetoException { if (pce == null) { throw new NullPointerException(Messages.getString("beans.1C")); //$NON-NLS-1$ } } /** * Serializes children to the given object input stream. *

* The implementation iterates through all children and writes out pairs * of child object and BCSChild object if the child is * serializable (implements Serialization.

*

* This method is called by writeObject() if the context * works standalone. Or if this support object is a delegate of another * BeanContext implementation, then this method should be * called by the peer to avoid the 'chicken and egg' problem during * deserialization.

* * @param oos the stream to write * @throws IOException if I/O exception occurs */ public final void writeChildren(ObjectOutputStream oos) throws IOException { boolean origSer = serializing; serializing = true; try { int count = 0; synchronized (children) { for (Iterator iter = children.values().iterator(); iter .hasNext();) { BCSChild bcsc = (BCSChild) iter.next(); if (bcsc.child instanceof Serializable && (bcsc.proxyPeer == null || bcsc.proxyPeer instanceof Serializable)) { oos.writeObject(bcsc.child); oos.writeObject(bcsc); count++; } } } // what if count not equals to serializable? if (count != serializable) { throw new IOException(Messages.getString("beans.6F")); } } finally { serializing = origSer; } } /** * The implementation goes through following steps: *

*

    *
  1. Writes out non-transient properties by calling * defaultWriteObject(), especially the * serializable indicating the number of serializable * children.
  2. *
  3. Calls bcsPreSerializationHook().
  4. *
  5. Writes out children by calling writeChildren() if * this context works standalone. Otherwise it is the peer's * responsibility to call writeChildren() after this object * is serialized.
  6. *
  7. Writes out serializable membership listeners.
  8. *
*

* * @param oos the object output stream * @throws IOException if I/O exception occurs */ private void writeObject(ObjectOutputStream oos) throws IOException { boolean origSer = serializing; serializing = true; try { oos.defaultWriteObject(); bcsPreSerializationHook(oos); if (this == getBeanContextPeer()) { writeChildren(oos); } synchronized (bcmListeners) { serialize(oos, bcmListeners); } } finally { serializing = origSer; } } /** * The implementation goes through following steps: *

*

    *
  1. Reads non-transient properties by calling * defaultReadObject().
  2. *
  3. Calls bcsPreDeserializationHook().
  4. *
  5. Reads children by calling readChildren() if * this context works standalone. Otherwise it is the peer's * responsibility to call readChildren() after this object * is deserialized.
  6. *
  7. Reads serializable membership listeners.
  8. *
*

* * @param ois the object input stream * @throws IOException if I/O error occurs * @throws ClassNotFoundException if class of read object is not found */ private void readObject(ObjectInputStream ois) throws IOException, ClassNotFoundException { ois.defaultReadObject(); initialize(); // init transient fields bcsPreDeserializationHook(ois); if (this == getBeanContextPeer()) { readChildren(ois); } synchronized (bcmListeners) { deserialize(ois, bcmListeners); } } /* * Increase variable serializable if child and proxyPeer fields of the given * BCSChild object are serializable */ private void addSerializable(BCSChild bcsc) { if (bcsc.child instanceof Serializable && (bcsc.proxyPeer == null || bcsc.proxyPeer instanceof Serializable)) { serializable++; } } /* * Decrease variable serializable if child and proxyPeer fields of the given * BCSChild object are serializable */ private void removeSerializable(BCSChild bcsc) { if (serializable > 0 && bcsc.child instanceof Serializable && (bcsc.proxyPeer == null || bcsc.proxyPeer instanceof Serializable)) { serializable--; } } }




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