| /* |
| * 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.comparators; |
| |
| import java.util.Comparator; |
| |
| import org.apache.tools.ant.types.DataType; |
| import org.apache.tools.ant.types.Resource; |
| |
| /** |
| * Abstract Resource Comparator. |
| * @since Ant 1.7 |
| */ |
| public abstract class ResourceComparator extends DataType implements Comparator { |
| |
| /** |
| * Compare two objects. |
| * @param foo the first Object. |
| * @param bar the second Object. |
| * @return a negative integer, zero, or a positive integer as the first |
| * argument is less than, equal to, or greater than the second. |
| * @throws ClassCastException if either argument is null. |
| */ |
| public final int compare(Object foo, Object bar) { |
| dieOnCircularReference(); |
| ResourceComparator c = |
| isReference() ? (ResourceComparator) getCheckedRef() : this; |
| return c.resourceCompare((Resource) foo, (Resource) bar); |
| } |
| |
| /** |
| * Test for equality with this ResourceComparator. |
| * @param o the Object to compare against. |
| * @return true if the specified Object equals this one. |
| */ |
| public boolean equals(Object o) { |
| if (isReference()) { |
| return getCheckedRef().equals(o); |
| } |
| if (o == null) { |
| return false; |
| } |
| return o == this || o.getClass().equals(getClass()); |
| } |
| |
| /** |
| * Hashcode based on the rules for equality. |
| * @return a hashcode. |
| */ |
| public synchronized int hashCode() { |
| if (isReference()) { |
| return getCheckedRef().hashCode(); |
| } |
| return getClass().hashCode(); |
| } |
| |
| /** |
| * Compare two Resources. |
| * @param foo the first Resource. |
| * @param bar the second Resource. |
| * @return a negative integer, zero, or a positive integer as the first |
| * argument is less than, equal to, or greater than the second. |
| */ |
| protected abstract int resourceCompare(Resource foo, Resource bar); |
| |
| } |