001/**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.camel.impl.cloud;
018
019import java.util.List;
020import java.util.concurrent.ThreadLocalRandom;
021
022import org.apache.camel.cloud.ServiceChooser;
023import org.apache.camel.cloud.ServiceDefinition;
024import org.apache.camel.util.ObjectHelper;
025
026public class RandomServiceChooser implements ServiceChooser {
027    @Override
028    public ServiceDefinition choose(List<ServiceDefinition> definitions) {
029        // Fail if the service definition list is null or empty
030        if (ObjectHelper.isEmpty(definitions)) {
031            throw new IllegalArgumentException("The ServiceDefinition list should not be empty");
032        }
033
034        int size = definitions.size();
035        if (size == 1) {
036            return  definitions.get(0);
037        } else {
038            return definitions.get(ThreadLocalRandom.current().nextInt(size));
039        }
040    }
041
042    @Override
043    public String toString() {
044        return "RandomServiceChooser";
045    }
046}