001 /* 002 * Copyright 2009 Red Hat, Inc. 003 * Red Hat licenses this file to you under the Apache License, version 004 * 2.0 (the "License"); you may not use this file except in compliance 005 * with the License. You may obtain a copy of the License at 006 * http://www.apache.org/licenses/LICENSE-2.0 007 * Unless required by applicable law or agreed to in writing, software 008 * distributed under the License is distributed on an "AS IS" BASIS, 009 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or 010 * implied. See the License for the specific language governing 011 * permissions and limitations under the License. 012 */ 013 014 package org.hornetq.api.core.client.loadbalance; 015 016 import org.hornetq.utils.Random; 017 018 /** 019 * RoundRobinConnectionLoadBalancingPolicy corresponds to a round-robin load-balancing policy. 020 * 021 * <br> 022 * The first call to {@link #select(int)} will return a random integer between {@code 0} (inclusive) and {@code max} (exclusive). 023 * Subsequent calls will then return an integer in a round-robin fashion. 024 * 025 * @author <a href="mailto:tim.fox@jboss.com">Tim Fox</a> 026 * 027 * Created 28 Nov 2008 10:21:08 028 * 029 * 030 */ 031 public class RoundRobinConnectionLoadBalancingPolicy implements ConnectionLoadBalancingPolicy 032 { 033 private final Random random = new Random(); 034 035 private boolean first = true; 036 037 private int pos; 038 039 public int select(final int max) 040 { 041 if (first) 042 { 043 // We start on a random one 044 pos = random.getRandom().nextInt(max); 045 046 first = false; 047 } 048 else 049 { 050 pos++; 051 052 if (pos >= max) 053 { 054 pos = 0; 055 } 056 } 057 058 return pos; 059 } 060 }