pom.xml

@@ -210,5 +210,13 @@
 				</exclusion>
 			</exclusions>
 		</dependency>
+		<!-- https://mvnrepository.com/artifact/org.objenesis/objenesis -->
+		<dependency>
+			<groupId>org.objenesis</groupId>
+			<artifactId>objenesis</artifactId>
+			<version>2.6</version>
+			<scope>test</scope>
+		</dependency>
+
 	</dependencies>
 </project>

src/main/java/buttondevteam/discordplugin/DiscordPlugin.java

@@ -49,6 +49,8 @@ public class DiscordPlugin extends JavaPlugin implements IListener<ReadyEvent> {
 	public void onEnable() {
 		try {
 			Bukkit.getLogger().info("Initializing DiscordPlugin...");
+			PlayerListWatcher.hookUp();
+			Bukkit.getLogger().info("Finished hooking into the player list");
 			plugin = this;
 			lastannouncementtime = getConfig().getLong("lastannouncementtime");
 			lastseentime = getConfig().getLong("lastseentime");

src/main/java/buttondevteam/discordplugin/PlayerListWatcher.java

@@ -0,0 +1,352 @@
+package buttondevteam.discordplugin;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
+import java.util.List;
+import java.util.UUID;
+
+import org.bukkit.Bukkit;
+import org.bukkit.Location;
+import org.bukkit.craftbukkit.v1_12_R1.CraftServer;
+import org.bukkit.event.player.PlayerTeleportEvent.TeleportCause;
+import org.objenesis.ObjenesisStd;
+
+import com.mojang.authlib.GameProfile;
+
+import buttondevteam.discordplugin.listeners.MCChatListener;
+import buttondevteam.lib.TBMCCoreAPI;
+import lombok.val;
+import net.minecraft.server.v1_12_R1.AdvancementDataPlayer;
+import net.minecraft.server.v1_12_R1.DedicatedPlayerList;
+import net.minecraft.server.v1_12_R1.DedicatedServer;
+import net.minecraft.server.v1_12_R1.Entity;
+import net.minecraft.server.v1_12_R1.EntityHuman;
+import net.minecraft.server.v1_12_R1.EntityPlayer;
+import net.minecraft.server.v1_12_R1.GameProfileBanList;
+import net.minecraft.server.v1_12_R1.IChatBaseComponent;
+import net.minecraft.server.v1_12_R1.IpBanList;
+import net.minecraft.server.v1_12_R1.LoginListener;
+import net.minecraft.server.v1_12_R1.MinecraftServer;
+import net.minecraft.server.v1_12_R1.NBTTagCompound;
+import net.minecraft.server.v1_12_R1.NetworkManager;
+import net.minecraft.server.v1_12_R1.OpList;
+import net.minecraft.server.v1_12_R1.Packet;
+import net.minecraft.server.v1_12_R1.ScoreboardServer;
+import net.minecraft.server.v1_12_R1.ServerStatisticManager;
+import net.minecraft.server.v1_12_R1.WhiteList;
+import net.minecraft.server.v1_12_R1.World;
+import net.minecraft.server.v1_12_R1.WorldServer;
+
+public class PlayerListWatcher extends DedicatedPlayerList {
+	private DedicatedPlayerList plist;
+
+	public PlayerListWatcher(DedicatedServer minecraftserver) {
+		super(minecraftserver); // <-- Does some init stuff and calls Bukkit.setServer() so we have to use Objenesis
+	}
+
+	@Override
+	public void sendMessage(IChatBaseComponent ichatbasecomponent, boolean flag) {
+		super.sendMessage(ichatbasecomponent, flag);
+		MCChatListener.sendSystemMessageToChat(ichatbasecomponent.toPlainText());
+	}
+
+	public static void hookUp() {
+		try {
+			Field conf = CraftServer.class.getDeclaredField("console");
+			conf.setAccessible(true);
+			val server = (MinecraftServer) conf.get(Bukkit.getServer());
+			val plw = new ObjenesisStd().newInstance(PlayerListWatcher.class); // Cannot call super constructor
+			plw.plist = (DedicatedPlayerList) server.getPlayerList();
+			plw.maxPlayers = plw.plist.getMaxPlayers();
+			Field plf = plw.getClass().getField("players");
+			plf.setAccessible(true);
+			Field modf = plf.getClass().getDeclaredField("modifiers");
+			modf.setAccessible(true);
+			modf.set(plf, plf.getModifiers() & ~Modifier.FINAL);
+			plf.set(plw, plw.plist.players);
+			server.a(plw);
+		} catch (Exception e) {
+			TBMCCoreAPI.SendException("Error while hacking the player list!", e);
+		}
+	}
+
+	public void a(EntityHuman entityhuman, IChatBaseComponent ichatbasecomponent) {
+		plist.a(entityhuman, ichatbasecomponent);
+	}
+
+	public ServerStatisticManager a(EntityHuman entityhuman) {
+		return plist.a(entityhuman);
+	}
+
+	public void a(EntityPlayer entityplayer, int i) {
+		plist.a(entityplayer, i);
+	}
+
+	public void a(EntityPlayer entityplayer, WorldServer worldserver) {
+		plist.a(entityplayer, worldserver);
+	}
+
+	public NBTTagCompound a(EntityPlayer entityplayer) {
+		return plist.a(entityplayer);
+	}
+
+	public void a(int i) {
+		plist.a(i);
+	}
+
+	public void a(NetworkManager networkmanager, EntityPlayer entityplayer) {
+		plist.a(networkmanager, entityplayer);
+	}
+
+	public void a(Packet<?> packet, int i) {
+		plist.a(packet, i);
+	}
+
+	public EntityPlayer a(UUID uuid) {
+		return plist.a(uuid);
+	}
+
+	public void addOp(GameProfile gameprofile) {
+		plist.addOp(gameprofile);
+	}
+
+	public void addWhitelist(GameProfile gameprofile) {
+		plist.addWhitelist(gameprofile);
+	}
+
+	public EntityPlayer attemptLogin(LoginListener loginlistener, GameProfile gameprofile, String hostname) {
+		return plist.attemptLogin(loginlistener, gameprofile, hostname);
+	}
+
+	public String b(boolean flag) {
+		return plist.b(flag);
+	}
+
+	public void b(EntityHuman entityhuman, IChatBaseComponent ichatbasecomponent) {
+		plist.b(entityhuman, ichatbasecomponent);
+	}
+
+	public void b(EntityPlayer entityplayer, WorldServer worldserver) {
+		plist.b(entityplayer, worldserver);
+	}
+
+	public List<EntityPlayer> b(String s) {
+		return plist.b(s);
+	}
+
+	public Location calculateTarget(Location enter, World target) {
+		return plist.calculateTarget(enter, target);
+	}
+
+	public void changeDimension(EntityPlayer entityplayer, int i, TeleportCause cause) {
+		plist.changeDimension(entityplayer, i, cause);
+	}
+
+	public void changeWorld(Entity entity, int i, WorldServer worldserver, WorldServer worldserver1) {
+		plist.changeWorld(entity, i, worldserver, worldserver1);
+	}
+
+	public int d() {
+		return plist.d();
+	}
+
+	public void d(EntityPlayer entityplayer) {
+		plist.d(entityplayer);
+	}
+
+	public String disconnect(EntityPlayer entityplayer) {
+		return plist.disconnect(entityplayer);
+	}
+
+	public boolean equals(Object obj) {
+		return plist.equals(obj);
+	}
+
+	public String[] f() {
+		return plist.f();
+	}
+
+	public void f(EntityPlayer entityplayer) {
+		plist.f(entityplayer);
+	}
+
+	public boolean f(GameProfile gameprofile) {
+		return plist.f(gameprofile);
+	}
+
+	public GameProfile[] g() {
+		return plist.g();
+	}
+
+	public boolean getHasWhitelist() {
+		return plist.getHasWhitelist();
+	}
+
+	public IpBanList getIPBans() {
+		return plist.getIPBans();
+	}
+
+	public int getMaxPlayers() {
+		return plist.getMaxPlayers();
+	}
+
+	public OpList getOPs() {
+		return plist.getOPs();
+	}
+
+	public EntityPlayer getPlayer(String s) {
+		return plist.getPlayer(s);
+	}
+
+	public int getPlayerCount() {
+		return plist.getPlayerCount();
+	}
+
+	public GameProfileBanList getProfileBans() {
+		return plist.getProfileBans();
+	}
+
+	public String[] getSeenPlayers() {
+		return plist.getSeenPlayers();
+	}
+
+	public DedicatedServer getServer() {
+		return plist.getServer();
+	}
+
+	public WhiteList getWhitelist() {
+		return plist.getWhitelist();
+	}
+
+	public String[] getWhitelisted() {
+		return plist.getWhitelisted();
+	}
+
+	public AdvancementDataPlayer h(EntityPlayer entityplayer) {
+		return plist.h(entityplayer);
+	}
+
+	public int hashCode() {
+		return plist.hashCode();
+	}
+
+	public boolean isOp(GameProfile gameprofile) {
+		return plist.isOp(gameprofile);
+	}
+
+	public boolean isWhitelisted(GameProfile gameprofile) {
+		return plist.isWhitelisted(gameprofile);
+	}
+
+	public EntityPlayer moveToWorld(EntityPlayer entityplayer, int i, boolean flag, Location location,
+			boolean avoidSuffocation) {
+		return plist.moveToWorld(entityplayer, i, flag, location, avoidSuffocation);
+	}
+
+	public EntityPlayer moveToWorld(EntityPlayer entityplayer, int i, boolean flag) {
+		return plist.moveToWorld(entityplayer, i, flag);
+	}
+
+	public String[] n() {
+		return plist.n();
+	}
+
+	public void onPlayerJoin(EntityPlayer entityplayer, String joinMessage) {
+		plist.onPlayerJoin(entityplayer, joinMessage);
+	}
+
+	public EntityPlayer processLogin(GameProfile gameprofile, EntityPlayer player) {
+		return plist.processLogin(gameprofile, player);
+	}
+
+	public void reload() {
+		plist.reload();
+	}
+
+	public void reloadWhitelist() {
+		plist.reloadWhitelist();
+	}
+
+	public void removeOp(GameProfile gameprofile) {
+		plist.removeOp(gameprofile);
+	}
+
+	public void removeWhitelist(GameProfile gameprofile) {
+		plist.removeWhitelist(gameprofile);
+	}
+
+	public void repositionEntity(Entity entity, Location exit, boolean portal) {
+		plist.repositionEntity(entity, exit, portal);
+	}
+
+	public int s() {
+		return plist.s();
+	}
+
+	public void savePlayers() {
+		plist.savePlayers();
+	}
+
+	@SuppressWarnings("rawtypes")
+	public void sendAll(Packet packet, EntityHuman entityhuman) {
+		plist.sendAll(packet, entityhuman);
+	}
+
+	@SuppressWarnings("rawtypes")
+	public void sendAll(Packet packet, World world) {
+		plist.sendAll(packet, world);
+	}
+
+	public void sendAll(Packet<?> packet) {
+		plist.sendAll(packet);
+	}
+
+	public void sendMessage(IChatBaseComponent ichatbasecomponent) {
+		plist.sendMessage(ichatbasecomponent);
+	}
+
+	public void sendMessage(IChatBaseComponent[] iChatBaseComponents) {
+		plist.sendMessage(iChatBaseComponents);
+	}
+
+	public void sendPacketNearby(EntityHuman entityhuman, double d0, double d1, double d2, double d3, int i,
+			Packet<?> packet) {
+		plist.sendPacketNearby(entityhuman, d0, d1, d2, d3, i, packet);
+	}
+
+	public void sendScoreboard(ScoreboardServer scoreboardserver, EntityPlayer entityplayer) {
+		plist.sendScoreboard(scoreboardserver, entityplayer);
+	}
+
+	public void setHasWhitelist(boolean flag) {
+		plist.setHasWhitelist(flag);
+	}
+
+	public void setPlayerFileData(WorldServer[] aworldserver) {
+		plist.setPlayerFileData(aworldserver);
+	}
+
+	public NBTTagCompound t() {
+		return plist.t();
+	}
+
+	public void tick() {
+		plist.tick();
+	}
+
+	public String toString() {
+		return plist.toString();
+	}
+
+	public void u() {
+		plist.u();
+	}
+
+	public void updateClient(EntityPlayer entityplayer) {
+		plist.updateClient(entityplayer);
+	}
+
+	public List<EntityPlayer> v() {
+		return plist.v();
+	}
+}