| /* |
| * 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.tools.ant.types.resources; |
| |
| import java.util.List; |
| import java.util.Iterator; |
| import java.util.ArrayList; |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.HashSet; |
| import java.util.Set; |
| |
| import org.apache.tools.ant.types.Resource; |
| import org.apache.tools.ant.types.ResourceCollection; |
| |
| /** |
| * ResourceCollection representing the union of multiple nested ResourceCollections. |
| * @since Ant 1.7 |
| */ |
| public class Union extends BaseResourceCollectionContainer { |
| |
| /** |
| * Static convenience method to union an arbitrary set of Resources. |
| * @param rc a ResourceCollection. |
| * @return a Union. |
| */ |
| public static Union getInstance(ResourceCollection rc) { |
| return rc instanceof Union ? (Union) rc : new Union(rc); |
| } |
| |
| /** |
| * Default constructor. |
| */ |
| public Union() { |
| } |
| |
| /** |
| * Convenience constructor. |
| * @param rc the ResourceCollection to add. |
| */ |
| public Union(ResourceCollection rc) { |
| add(rc); |
| } |
| |
| /** |
| * Returns all Resources in String format. Provided for |
| * convenience in implementing Path. |
| * @return String array of Resources. |
| */ |
| public String[] list() { |
| if (isReference()) { |
| return ((Union) getCheckedRef()).list(); |
| } |
| Collection result = getCollection(true); |
| return (String[]) (result.toArray(new String[result.size()])); |
| } |
| |
| /** |
| * Convenience method. |
| * @return Resource[] |
| */ |
| public Resource[] listResources() { |
| if (isReference()) { |
| return ((Union) getCheckedRef()).listResources(); |
| } |
| Collection result = getCollection(); |
| return (Resource[]) (result.toArray(new Resource[result.size()])); |
| } |
| |
| /** |
| * Unify the contained Resources. |
| * @return a Collection of Resources. |
| */ |
| protected Collection getCollection() { |
| return getCollection(false); |
| } |
| |
| /** |
| * Unify the contained Resources. |
| * @param asString indicates whether the resulting Collection |
| * should contain Strings instead of Resources. |
| * @return a Collection of Resources. |
| */ |
| protected Collection getCollection(boolean asString) { |
| List rc = getResourceCollections(); |
| if (rc.isEmpty()) { |
| return Collections.EMPTY_LIST; |
| } |
| //preserve order-encountered using a list; enforce set logic manually: |
| // (LinkedHashSet better, but JDK 1.4+) |
| ArrayList union = new ArrayList(rc.size() * 2); |
| // Use a set as list.contains() can be expensive for lots of resources |
| Set set = new HashSet(rc.size() * 2); |
| for (Iterator rcIter = rc.iterator(); rcIter.hasNext();) { |
| for (Iterator r = nextRC(rcIter).iterator(); r.hasNext();) { |
| Object o = r.next(); |
| if (asString) { |
| o = o.toString(); |
| } |
| if (set.add(o)) { |
| union.add(o); |
| } |
| } |
| } |
| return union; |
| } |
| |
| private static ResourceCollection nextRC(Iterator i) { |
| return (ResourceCollection) i.next(); |
| } |
| } |
| |