org.apache.tools.ant.types.resources.BaseResourceCollectionWrapper Maven / Gradle / Ivy
/*
* 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.Collection;
import java.util.Iterator;
/**
* Base class for a ResourceCollection that wraps a single nested
* ResourceCollection.
* @since Ant 1.7
*/
public abstract class BaseResourceCollectionWrapper
extends AbstractResourceCollectionWrapper {
private Collection coll = null;
protected Iterator createIterator() {
return cacheCollection().iterator();
}
protected int getSize() {
return cacheCollection().size();
}
/**
* Template method for subclasses to return a Collection of Resources.
* @return Collection.
*/
protected abstract Collection getCollection();
private synchronized Collection cacheCollection() {
if (coll == null || !isCache()) {
coll = getCollection();
}
return coll;
}
}