studio.raptor.ddal.config.fetcher.FetcherHolder Maven / Gradle / Ivy
/*
* 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 studio.raptor.ddal.config.fetcher;
import java.util.Iterator;
import java.util.ServiceLoader;
import studio.raptor.ddal.common.exception.GenericException;
import studio.raptor.ddal.config.exception.ConfigErrCodes;
/**
* Config获取器持有者
*
* @author Charley
* @since 1.0
*/
public class FetcherHolder {
private static ConfigFetcher configFetcher;
public static ConfigFetcher get() {
if (null == configFetcher) {
ServiceLoader serviceLoader = ServiceLoader.load(ConfigFetcher.class);
Iterator fetcherIt = serviceLoader.iterator();
if (fetcherIt.hasNext()) {
configFetcher = fetcherIt.next();
} else {
throw new GenericException(ConfigErrCodes.CONFIG_106);
}
}
return configFetcher;
}
}