/*
* 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.brooklyn.core.catalog.internal;
import java.util.Collections;
import java.util.Comparator;
import org.apache.brooklyn.api.catalog.CatalogItem;
import org.apache.brooklyn.util.text.VersionComparator;
/**
* Largest version first order.
*
* When using the comparator to sort - first using symbolicName
* and if equal puts larger versions first, snapshots at the back.
*/
public class CatalogItemComparator<T,SpecT> implements Comparator<CatalogItem<T, SpecT>> {
public static final CatalogItemComparator<?, ?> INSTANCE = new CatalogItemComparator<Object, Object>();
@SuppressWarnings("unchecked")
public static <T,SpecT> CatalogItemComparator<T,SpecT> getInstance() {
return (CatalogItemComparator<T, SpecT>) INSTANCE;
}
@Override
public int compare(CatalogItem<T, SpecT> o1, CatalogItem<T, SpecT> o2) {
int symbolicNameComparison = o1.getSymbolicName().compareTo(o2.getSymbolicName());
if (symbolicNameComparison != 0) {
return symbolicNameComparison;
} else {
return Collections.reverseOrder(VersionComparator.INSTANCE).compare(o1.getVersion(), o2.getVersion());
}
}
}