/*
* 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 org.apache.jackrabbit.spi.commons.namespace;
import java.util.Set;
import java.util.HashSet;
import java.util.Iterator;
/**
* Provides default implementations for the methods:
* <ul>
* <li>{@link #addListener(NamespaceListener)}</li>
* <li>{@link #removeListener(NamespaceListener)}</li>
* </ul>
* Subclasses may overwrite those methods with more efficient implementations
* e.g. using caching. This class also adds optional support for
* {@link NamespaceListener}s. To enable listener support call the constructor
* with <code>supportListeners</code> set to <code>true</code>. The default
* constructor will not enable listener support and all listener related
* methods will throw an {@link UnsupportedOperationException} in that case.
*
* @deprecated https://issues.apache.org/jira/browse/JCR-1700
*/
public abstract class AbstractNamespaceResolver implements NamespaceResolver {
private final Set listeners;
/**
* Creates a <code>AbstractNamespaceResolver</code> without listener
* support.
*/
public AbstractNamespaceResolver() {
this(false);
}
/**
* Creates a <code>AbstractNamespaceResolver</code> with listener support if
* <code>supportListeners</code> is set to <code>true</code>.
*
* @param supportListeners if <code>true</code> listener are supported by
* this instance.
*/
public AbstractNamespaceResolver(boolean supportListeners) {
if (supportListeners) {
listeners = new HashSet();
} else {
listeners = null;
}
}
//--------------------------------------------< NamespaceListener support >
/**
* Registers <code>listener</code> to get notifications when namespace
* mappings change.
*
* @param listener the listener to register.
* @throws UnsupportedOperationException if listener support is not enabled
* for this <code>AbstractNamespaceResolver</code>.
*/
public void addListener(NamespaceListener listener) {
if (listeners == null) {
throw new UnsupportedOperationException("addListener");
}
synchronized (listeners) {
listeners.add(listener);
}
}
/**
* Removes the <code>listener</code> from this <code>NamespaceRegistery</code>.
*
* @param listener the listener to remove.
* @throws UnsupportedOperationException if listener support is not enabled
* for this <code>AbstractNamespaceResolver</code>.
*/
public void removeListener(NamespaceListener listener) {
if (listeners == null) {
throw new UnsupportedOperationException("removeListener");
}
synchronized (listeners) {
listeners.remove(listener);
}
}
/**
* Notifies the listeners that a new namespace <code>uri</code> has been
* added and mapped to <code>prefix</code>.
*
* @param prefix the prefix.
* @param uri the namespace uri.
*/
protected void notifyNamespaceAdded(String prefix, String uri) {
if (listeners == null) {
throw new UnsupportedOperationException("notifyNamespaceAdded");
}
// addition is infrequent compared to listener registration
// -> use copy-on-read
NamespaceListener[] currentListeners;
synchronized (listeners) {
int i = 0;
currentListeners = new NamespaceListener[listeners.size()];
for (Iterator it = listeners.iterator(); it.hasNext();) {
currentListeners[i++] = (NamespaceListener) it.next();
}
}
for (int i = 0; i < currentListeners.length; i++) {
currentListeners[i].namespaceAdded(prefix, uri);
}
}
/**
* Notifies listeners that an existing namespace uri has been remapped
* to a new prefix.
*
* @param oldPrefix the old prefix.
* @param newPrefix the new prefix.
* @param uri the associated namespace uri.
*/
protected void notifyNamespaceRemapped(String oldPrefix,
String newPrefix,
String uri) {
if (listeners == null) {
throw new UnsupportedOperationException("notifyNamespaceRemapped");
}
// remapping is infrequent compared to listener registration
// -> use copy-on-read
NamespaceListener[] currentListeners;
synchronized (listeners) {
int i = 0;
currentListeners = new NamespaceListener[listeners.size()];
for (Iterator it = listeners.iterator(); it.hasNext();) {
currentListeners[i++] = (NamespaceListener) it.next();
}
}
for (int i = 0; i < currentListeners.length; i++) {
currentListeners[i].namespaceRemapped(oldPrefix, newPrefix, uri);
}
}
/**
* Notifies the listeners that the namespace with the given <code>uri</code>
* has been removed from the mapping.
*
* @param uri the namespace uri.
* @see NamespaceListener#namespaceRemoved(String)
*/
protected void notifyNamespaceRemoved(String uri) {
if (listeners == null) {
throw new UnsupportedOperationException("notifyNamespaceRemapped");
}
// removal is infrequent compared to listener registration
// -> use copy-on-read
NamespaceListener[] currentListeners;
synchronized (listeners) {
int i = 0;
currentListeners = new NamespaceListener[listeners.size()];
for (Iterator it = listeners.iterator(); it.hasNext();) {
currentListeners[i++] = (NamespaceListener) it.next();
}
}
for (int i = 0; i < currentListeners.length; i++) {
currentListeners[i].namespaceRemoved(uri);
}
}
}