vaadin-framework/server/src/main/java/com/vaadin/server/SerializableComparator.java

/*
 * Copyright 2000-2016 Vaadin Ltd.
 *
 * 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 com.vaadin.server;

import java.io.Serializable;
import java.util.Comparator;

/**
 * A {@link Comparator} that is also {@link Serializable}.
 *
 * @author Vaadin Ltd
 * @param <T>
 *            the type of objects that may be compared by this comparator
 * @since 8.0
 *
 */
@FunctionalInterface
public interface SerializableComparator<T> extends Comparator<T>, Serializable {

    /**
     * Returns a {@link SerializableComparator} instance which delegates its
     * logic to the provided {@code comparator}.
     *
     * @param comparator
     *            comparator to convert
     * @param <T>
     *            the type of objects that may be compared by this comparator
     * @param <C>
     *            the comparator type
     * @return a SerializableComparator view of the {@code comparator}
     */
    static <C extends Comparator<T> & Serializable, T> SerializableComparator<T> asInstance(
            C comparator) {
        return (arg1, arg2) -> comparator.compare(arg1, arg2);
    }
}