2 * ============LICENSE_START=======================================================
4 * ================================================================================
5 * Copyright (C) 2017-2018 AT&T Intellectual Property. All rights reserved.
6 * Modifications Copyright (C) 2019 Nordix Foundation.
7 * ================================================================================
8 * Licensed under the Apache License, Version 2.0 (the "License");
9 * you may not use this file except in compliance with the License.
10 * You may obtain a copy of the License at
12 * http://www.apache.org/licenses/LICENSE-2.0
14 * Unless required by applicable law or agreed to in writing, software
15 * distributed under the License is distributed on an "AS IS" BASIS,
16 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17 * See the License for the specific language governing permissions and
18 * limitations under the License.
19 * ============LICENSE_END=========================================================
22 package org.onap.policy.controlloop.actorserviceprovider;
24 import com.google.common.collect.ImmutableList;
26 import java.util.Iterator;
27 import java.util.ServiceLoader;
29 import org.onap.policy.controlloop.actorserviceprovider.spi.Actor;
30 import org.slf4j.Logger;
31 import org.slf4j.LoggerFactory;
33 public class ActorService {
35 private static final Logger logger = LoggerFactory.getLogger(ActorService.class);
36 private static ActorService service;
38 // USed to load actors
39 private final ServiceLoader<Actor> loader;
41 private ActorService() {
42 loader = ServiceLoader.load(Actor.class);
46 * Get the single instance.
48 * @return the instance
50 public static synchronized ActorService getInstance() {
51 if (service == null) {
52 service = new ActorService();
62 public ImmutableList<Actor> actors() {
63 Iterator<Actor> iter = loader.iterator();
64 logger.debug("returning actors");
65 while (iter.hasNext()) {
66 if (logger.isDebugEnabled()) {
67 logger.debug("Got {}", iter.next().actor());
71 return ImmutableList.copyOf(loader.iterator());