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52°North Iceland Statistics

There is a newer version: 2.0.0

/*
 * Copyright 2015 52°North Initiative for Geospatial Open Source
 * Software GmbH
 *
 * 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.n52.iceland.statistics.api.utils;

import java.util.Map;
import java.util.Objects;

import org.n52.iceland.statistics.api.interfaces.StatisticsServiceEventHandler;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class EventHandlerFinder {

    private static final Logger logger = LoggerFactory.getLogger(EventHandlerFinder.class);

    @SuppressWarnings("unchecked")
    public static  StatisticsServiceEventHandler findHandler(Object object, Map> handlers) {
        // Find concrete class
        String key = object.getClass().getSimpleName();
        logger.debug("Searching handler for object by key {} ", key);
        StatisticsServiceEventHandler handler = (StatisticsServiceEventHandler) handlers.get(key);

        // Find super class as handler
        if (handler == null) {
            Class superclass = object.getClass().getSuperclass();
            while (superclass != null) {
                key = superclass.getSimpleName();
                logger.debug("Try super class as key {}", key);
                handler = (StatisticsServiceEventHandler) handlers.get(key);
                if (handler != null) {
                    break;
                } else {
                    superclass = superclass.getSuperclass();
                }
            }
        }

        // Find default handler
        if (handler == null) {
            logger.debug("Not found using default handler by key 'default' if registered.");
            key = "default";
            handler = (StatisticsServiceEventHandler) handlers.get(key);
        }

        Objects.requireNonNull(handler, "Can not find handler for object: " + key);
        logger.debug("Key {} found.", key);
        return handler;
    }

    private EventHandlerFinder() {
    }
}