core/api/src/main/java/org/onosproject/ui/table/DefaultCellComparator.java

/*
 * 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;

/**
 * A default cell comparator. 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 class DefaultCellComparator implements CellComparator {
    @Override
    public int compare(Object o1, Object o2) {
        if (o1 == null && o2 == null) {
            return 0;       // o1 == o2
        }
        if (o1 == null) {
            return -1;      // o1 < o2
        }
        if (o2 == null) {
            return 1;       // o1 > o2
        }
        return o1.toString().compareTo(o2.toString());
    }
}