/**
* The MIT License
* Copyright (c) 2014-2016 Ilkka Seppälä
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package com.iluwatar.monostate;
import java.util.ArrayList;
import java.util.List;
/**
* The LoadBalancer class. This implements the MonoState pattern. It holds a series of servers. Upon
* receiving a new Request, it delegates the call to the servers in a Round Robin Fashion. Since all
* instances of the class share the same state, all instances will delegate to the same server on
* receiving a new Request.
*
*/
public class LoadBalancer {
private static List<Server> servers = new ArrayList<>();
private static int id;
private static int lastServedId;
static {
servers.add(new Server("localhost", 8081, ++id));
servers.add(new Server("localhost", 8080, ++id));
servers.add(new Server("localhost", 8082, ++id));
servers.add(new Server("localhost", 8083, ++id));
servers.add(new Server("localhost", 8084, ++id));
}
/**
* Add new server
*/
public final void addServer(Server server) {
synchronized (servers) {
servers.add(server);
}
}
public final int getNoOfServers() {
return servers.size();
}
public static int getLastServedId() {
return lastServedId;
}
/**
* Handle request
*/
public void serverRequest(Request request) {
if (lastServedId >= servers.size()) {
lastServedId = 0;
}
Server server = servers.get(lastServedId++);
server.serve(request);
}
}