org.apache.tools.ant.types.resources.Difference 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
*
* https://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.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.types.Resource;
import org.apache.tools.ant.types.ResourceCollection;
/**
* ResourceCollection representing the difference between
* two or more nested ResourceCollections.
* @since Ant 1.7
*/
public class Difference extends BaseResourceCollectionContainer {
/**
* Calculate the difference of the nested ResourceCollections.
* @return a Collection of Resources.
*/
@Override
protected Collection getCollection() {
List rcs = getResourceCollections();
int size = rcs.size();
if (size < 2) {
throw new BuildException(
"The difference of %d resource %s is undefined.", size,
size == 1 ? "collection" : "collections");
}
Set hs = new HashSet<>();
List al = new ArrayList<>();
for (ResourceCollection rc : rcs) {
for (Resource r : rc) {
if (hs.add(r)) {
al.add(r);
} else {
al.remove(r);
}
}
}
return al;
}
}