Java tutorial
/* * Copyright 2016 Exorath * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.exorath.simpleapi.impl.serverlist; import com.exorath.simpleapi.api.game.Game; import com.exorath.simpleapi.api.game.minigame.Minigame; import com.exorath.simpleapi.api.hub.Hub; import com.exorath.simpleapi.api.serverlist.GameServer; import com.exorath.simpleapi.api.hub.serverlist.ServerAddedEvent; import com.exorath.simpleapi.api.hub.serverlist.ServerRemovedEvent; import com.exorath.simpleapi.api.redis.RedisSubscriber; import com.exorath.simpleapi.api.serverlist.HubServer; import com.exorath.simpleapi.api.serverlist.Server; import com.exorath.simpleapi.api.serverlist.ServerListManager; import com.exorath.simpleapi.impl.SimpleAPIImpl; import com.google.gson.JsonObject; import com.google.gson.JsonParser; import org.apache.commons.lang3.Validate; import org.bukkit.Bukkit; import java.util.Collection; import java.util.HashMap; import java.util.HashSet; import java.util.Set; /** * This manager listens for Game Discovery Messages. See https://github.com/stink123456/SimpleAPI/wiki/Game-discovery for more info. * Created by Toon Sevrin on 5/17/2016. */ public class ServerListManagerImpl extends RedisSubscriber implements ServerListManager { private HashMap<String, Server> serversById = new HashMap<>(); private HashMap<String, Integer> serverExpiryById = new HashMap<>(); public ServerListManagerImpl() { super(Game.getRedisGameDiscoveryChannel()); } @Override public void onMessage(String channel, String message) { if (channel.equals(Game.getRedisGameDiscoveryChannel())) handleGameDiscoveryMessage(new JsonParser().parse(message).getAsJsonObject()); else if (channel.equals(Hub.getRedisHubDiscoveryChannel())) handleHubDiscoveryMessage(new JsonParser().parse(message).getAsJsonObject()); } /** * This is called when a Game-Discovery-Message is received through redis. It will add the game and update the expiry scheduler. * * @param message the Game-Discovery-Message */ public void handleGameDiscoveryMessage(JsonObject message) { Validate.isTrue(validateGameDiscoveryMessage(message), "SimpleAPI received a non-valid Game-Discovery-Message over the channel: " + Minigame.getRedisGameDiscoveryChannel()); GameServer gameServer = GameServerImpl.deserialize(message.get("gameserver").getAsJsonObject()); ServerAddedEvent event = new ServerAddedEvent(gameServer, message.get("expire").getAsInt()); Bukkit.getPluginManager().callEvent(event); if (event.isCancelled()) return; serversById.put(gameServer.getBungeeName(), gameServer); handleExpiry(gameServer.getBungeeName(), event.getExpireAfter()); } /** * This is called when a Hub-Discovery-Message is received through redis. It will add the hub and update the expiry scheduler. * * @param message the Hub-Discovery-Message */ public void handleHubDiscoveryMessage(JsonObject message) { Validate.isTrue(validateGameDiscoveryMessage(message), "SimpleAPI received a non-valid Hub-Discovery-Message over the channel: " + Minigame.getRedisGameDiscoveryChannel()); GameServer gameServer = GameServerImpl.deserialize(message.get("gameserver").getAsJsonObject()); ServerAddedEvent event = new ServerAddedEvent(gameServer, message.get("expire").getAsInt()); Bukkit.getPluginManager().callEvent(event); if (event.isCancelled()) return; serversById.put(gameServer.getBungeeName(), gameServer); handleExpiry(gameServer.getBungeeName(), event.getExpireAfter()); } /** * Updates the expiry scheduler with the new expiration time. * * @param bungeeId GameServerId to update expiration time of * @param expireAfterTicks after this time expires, the server will be removed if it has not been re-registered through the redis message */ public void handleExpiry(String bungeeId, int expireAfterTicks) { if (serverExpiryById.containsKey(bungeeId) && Bukkit.getScheduler().isQueued(serverExpiryById.get(bungeeId))) Bukkit.getScheduler().cancelTask(serverExpiryById.get(bungeeId)); serverExpiryById.put(bungeeId, Bukkit.getScheduler().scheduleSyncDelayedTask(SimpleAPIImpl.getInstance(), getOnExpire(bungeeId), expireAfterTicks)); } /** * Gets a {@link Runnable} that calls a GameServerRemoveEvent and removes the server with bungeeId from the list. * * @param bungeeId id of {@link GameServer} that should be remove * @return a {@link Runnable} that calls a GameServerRemoveEvent and removes the server with bungeeId from the list */ public Runnable getOnExpire(String bungeeId) { return () -> { if (serversById.containsKey(bungeeId)) { ServerRemovedEvent removedEvent = new ServerRemovedEvent(serversById.get(bungeeId)); Bukkit.getPluginManager().callEvent(removedEvent); if (removedEvent.isCancelled()) return; } serversById.remove(bungeeId); serverExpiryById.remove(bungeeId); }; } /** * Validates whether or not the provided Game-Discovery-Message is valid (Contains required keys). * * @param message Game-Discovery-Message to validate * @return true if the message is valid */ private static boolean validateGameDiscoveryMessage(JsonObject message) { return message.has("expire") && message.has("gameserver") && GameServerImpl.canDeserialize(message.get("gameserver").getAsJsonObject()); } /** * Validates whether or not the provided Hub-Discovery-Message is valid (Contains required keys). * * @param message Game-Discovery-Message to validate * @return true if the message is valid */ private static boolean validateHubDiscoveryMessage(JsonObject message) { return message.has("expire") && message.has("hubserver") && GameServerImpl.canDeserialize(message.get("hubserver").getAsJsonObject()); } @Override public Collection<GameServer> getGameServers() { return getServers(GameServer.class); } @Override public Collection<HubServer> getHubServers() { return getServers(HubServer.class); } private <T extends Server> Collection<T> getServers(Class<T> type) { Set<T> servers = new HashSet<>(); serversById.values().stream().filter(s -> type.isAssignableFrom(s.getClass())) .forEach(s -> servers.add((T) s)); return servers; } }