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; 020 021import org.apache.camel.cloud.ServiceChooser; 022import org.apache.camel.cloud.ServiceDefinition; 023import org.apache.camel.util.ObjectHelper; 024 025public class RoundRobinServiceChooser implements ServiceChooser { 026 private int counter = -1; 027 028 @Override 029 public synchronized ServiceDefinition choose(List<ServiceDefinition> definitions) { 030 // Fail if the service definition list is null or empty 031 if (ObjectHelper.isEmpty(definitions)) { 032 throw new IllegalArgumentException("The ServiceDefinition list should not be empty"); 033 } 034 035 int size = definitions.size(); 036 if (size == 1 || ++counter >= size) { 037 counter = 0; 038 } 039 040 return definitions.get(counter); 041 } 042 043 @Override 044 public String toString() { 045 return "RoundRobinServiceChooser"; 046 } 047}