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