| /* |
| * 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.cocoon.components.accessor; |
| |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| import org.apache.avalon.framework.CascadingRuntimeException; |
| import org.apache.avalon.framework.configuration.Configurable; |
| import org.apache.avalon.framework.configuration.Configuration; |
| import org.apache.avalon.framework.configuration.ConfigurationException; |
| import org.apache.avalon.framework.service.ServiceException; |
| import org.apache.avalon.framework.service.ServiceManager; |
| import org.apache.avalon.framework.service.ServiceSelector; |
| import org.apache.avalon.framework.service.Serviceable; |
| import org.apache.avalon.framework.thread.ThreadSafe; |
| |
| /** |
| * An accessor that handles a <code>Map</code> of accessors. |
| * @version $Id$ |
| */ |
| public class MapAccessor implements Accessor, Configurable, Serviceable, ThreadSafe { |
| |
| /** Reference to the accessors */ |
| private Map accessors; |
| |
| /** The service manager instance */ |
| private ServiceManager manager; |
| |
| /** |
| * The accessors that should be part of the map are configured |
| * through <code><element name="the key that will be used in |
| * the map" accessor="the name of the accessor"/></code>. |
| * |
| * @see org.apache.avalon.framework.configuration.Configurable#configure(org.apache.avalon.framework.configuration.Configuration) |
| */ |
| public void configure(Configuration config) throws ConfigurationException { |
| Map accessors = new HashMap(); |
| Configuration[] children = config.getChildren("element"); |
| for (int i = 0; i < children.length; i++) { |
| String accessor = children[i].getAttribute("accessor"); |
| // use the accessor name as name if nothing else is given |
| String name = children[i].getAttribute("name", accessor); |
| accessors.put(name, accessor); |
| } |
| this.accessors = new AccessorMap(accessors, this.manager); |
| } |
| |
| /** |
| * Set the current <code>ServiceManager</code> instance used by this |
| * <code>Serviceable</code>. |
| * @see org.apache.avalon.framework.service.Serviceable#service(org.apache.avalon.framework.service.ServiceManager) |
| */ |
| public void service(ServiceManager manager) throws ServiceException { |
| this.manager = manager; |
| } |
| |
| /** |
| * Get the map of accessors |
| * @see org.apache.cocoon.components.accessor.Accessor#getObject() |
| */ |
| public Object getObject() { |
| return this.accessors; |
| } |
| |
| /** |
| * Map that finds the accessor at access time. |
| */ |
| public static class AccessorMap extends HashMap { |
| |
| private ServiceManager manager; |
| |
| public AccessorMap(Map map, ServiceManager manager) { |
| super(map); |
| this.manager = manager; |
| } |
| |
| public Object get(Object key) { |
| String accessorName = (String)super.get(key); |
| if (accessorName == null) |
| return null; |
| ServiceSelector accessorSelector = null; |
| Accessor accessor = null; |
| try { |
| // Thread safe accessors could be looked up once and be cached |
| accessorSelector = |
| (ServiceSelector)this.manager.lookup(Accessor.ROLE + "Selector"); |
| accessor = (Accessor)accessorSelector.select(accessorName); |
| return accessor.getObject(); |
| } catch (ServiceException e) { |
| // FIXME: Don't know if this is the appropriate action |
| throw new CascadingRuntimeException("Trying to access non existing acessor: " + |
| accessorName, e); |
| } finally { |
| accessorSelector.release(accessor); |
| this.manager.release(accessorSelector); |
| } |
| } |
| |
| // The MapAccessor is thread safe so the map should be read only |
| public void clear() { |
| throw new UnsupportedOperationException("AccessorMap is read only"); |
| } |
| |
| public Object put(Object key, Object value) { |
| throw new UnsupportedOperationException("AccessorMap is read only"); |
| } |
| |
| public void putAll(Map m) { |
| throw new UnsupportedOperationException("AccessorMap is read only"); |
| } |
| |
| public Object remove(Object key) { |
| throw new UnsupportedOperationException("AccessorMap is read only"); |
| } |
| } |
| } |