org.onosproject.ui.table.cell.DefaultCellComparator Maven / Gradle / Ivy
/*
* Copyright 2015 Open Networking Laboratory
*
* Licensed 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.onosproject.ui.table.cell;
import org.onosproject.ui.table.CellComparator;
/**
* A default cell comparator.
*
* Verifies that the objects being compared are the same class.
* Looks to see if the objects being compared implement comparable and, if so,
* delegates to that; otherwise, implements a lexicographical compare function
* (i.e. string sorting). Uses the objects' toString() method and then
* compares the resulting strings. Note that null values are acceptable and
* are considered "smaller" than any non-null value.
*/
public final class DefaultCellComparator extends AbstractCellComparator {
// non-instantiable
private DefaultCellComparator() { }
@Override
@SuppressWarnings("unchecked")
protected int nonNullCompare(Object o1, Object o2) {
if (o1 instanceof Comparable) {
// if o2 is not the same class as o1, then compareTo will
// throw ClassCastException for us
return ((Comparable) o1).compareTo(o2);
}
return o1.toString().compareTo(o2.toString());
}
/**
* An instance of this class.
*/
public static final CellComparator INSTANCE = new DefaultCellComparator();
}