meecrowave-core/src/main/java/org/apache/meecrowave/service/Priotities.java

/*
 * 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.meecrowave.service;

import static java.util.Optional.ofNullable;

import javax.annotation.Priority;

public final class Priotities {
    private Priotities() {
        // no-op
    }

    private static int priorityOf(final Object i) {
        return ofNullable(i.getClass().getAnnotation(Priority.class))
                .map(Priority::value)
                .orElse(0);
    }

    public static <T> int sortByPriority(final T a, final T b) {
        return priorityOf(a) - priorityOf(b);
    }
}