Kotlin can't use 'this' on init - kotlin

Question

I want game to be set to a new instance of Game and I want to pass this into game. SO this is what I have.
var game: Game
init {
game = Game(this)
}
I have also tried
var game: Game = Game(this)
both threw a NullPointer at run time but it seems fine in Intellij and has no problem compiling. What am I doing wrong?
Stack Trace
org.bukkit.plugin.InvalidPluginException: java.lang.NullPointerException
at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:135) ~[server.jar:git-Spigot-21fe707-e1ebe52]
at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:329) ~[server.jar:git-Spigot-21fe707-e1ebe52]
at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:251) [server.jar:git-Spigot-21fe707-e1ebe52]
at org.bukkit.craftbukkit.v1_8_R3.CraftServer.loadPlugins(CraftServer.java:292) [server.jar:git-Spigot-21fe707-e1ebe52]
at net.minecraft.server.v1_8_R3.DedicatedServer.init(DedicatedServer.java:198) [server.jar:git-Spigot-21fe707-e1ebe52]
at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:525) [server.jar:git-Spigot-21fe707-e1ebe52]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_121]
Caused by: java.lang.NullPointerException
at org.bukkit.plugin.SimplePluginManager.registerEvents(SimplePluginManager.java:523) ~[server.jar:git-Spigot-21fe707-e1ebe52]
at me.darkpaladin.uhc.game.gameSettings.GameSettingsManager.addGameSettings(GameSettingsManager.kt:43) ~[?:?]
at me.darkpaladin.uhc.game.gameSettings.GameSettingsManager.<init>(GameSettingsManager.kt:20) ~[?:?]
at me.darkpaladin.uhc.game.Game.<init>(Game.kt:49) ~[?:?]
at me.darkpaladin.uhc.UHC.<init>(UHC.kt:20) ~[?:?]
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[?:1.8.0_121]
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[?:1.8.0_121]
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[?:1.8.0_121]
at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[?:1.8.0_121]
at java.lang.Class.newInstance(Class.java:442) ~[?:1.8.0_121]
at org.bukkit.plugin.java.PluginClassLoader.<init>(PluginClassLoader.java:76) ~[server.jar:git-Spigot-21fe707-e1ebe52]
at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:131) ~[server.jar:git-Spigot-21fe707-e1ebe52]
... 6 more
UHC Class
var game: Game
init {
game = Game(this)
}
override fun onReady() {
// new Lobby(Bukkit.getWorld("world"), this, false);
TeamManager()
registerCommands()
}
fun registerCommands() {
val c = commandHandler
c.addCommand(
TeamCommand(),
SetGameTypeCommand(game),
ClaimHostCommand(game),
StartGameCommand(game),
ScenarioManagerCommand(game),
KillTopCommand(game),
ConfigCommand(game),
ScatterCommand(game)
)
}
fun registerListeners() {
val p = Bukkit.getPluginManager()
p.registerEvents(GamePlayerListener(game), this)
}
Game Class
package me.darkpaladin.uhc.game
import me.darkpaladin.core.Core
import me.darkpaladin.core.utils.CoreUtils
import me.darkpaladin.core.utils.PacketUtils
import me.darkpaladin.uhc.UHC
import me.darkpaladin.uhc.events.GameStartEvent
import me.darkpaladin.uhc.events.GameStopEvent
import me.darkpaladin.uhc.game.gameEvents.GameEvent
import me.darkpaladin.uhc.game.gameEvents.GameEventRunnable
import me.darkpaladin.uhc.game.gamePlayers.GamePlayer
import me.darkpaladin.uhc.game.gamePlayers.GamePlayerManager
import me.darkpaladin.uhc.game.gameSettings.GameSettingsManager
import me.darkpaladin.uhc.scenarios.ScenarioManager
import org.apache.commons.lang.WordUtils
import org.bukkit.*
import org.bukkit.entity.Item
import org.bukkit.entity.Monster
import org.bukkit.entity.Player
import org.bukkit.scheduler.BukkitRunnable
import java.util.*
/**
* Created by Caleb on 4/28/2017.
*/
class Game(private val plugin: UHC) {
var gameType = GameType.NORMAL
var gameState = GameState.SETTING_UP
var gameStartTicks = (CoreUtils.ticksPerSecond * 10).toLong()
var finalHealTime = (CoreUtils.ticksPerSecond * 15).toLong()
var pvpTicks = (CoreUtils.ticksPerSecond * 20).toLong()
var meetupTicks = (CoreUtils.ticksPerSecond * 25).toLong()
var isBorderShrink = true
var episodeLength = (CoreUtils.ticksPerMinute * 20).toLong()
private var episode = 1
private val worlds = ArrayList<World>()
private val gameEvents = ArrayList<GameEvent>()
var gameTicks: Long = 0L
var hostUuid: UUID? = null
val scenarioManager: ScenarioManager = ScenarioManager(this)
val gamePlayerManager: GamePlayerManager = GamePlayerManager()
val gameSettingsManager: GameSettingsManager = GameSettingsManager(this)
private val instance: Game
init {
worlds.add(Bukkit.getWorld("world")) //TODO: remove
instance = this
}
val overworld: World?
get() = getWorldWithEnvironment(World.Environment.NORMAL)
val nether: World?
get() = getWorldWithEnvironment(World.Environment.NETHER)
val end: World?
get() = getWorldWithEnvironment(World.Environment.THE_END)
fun getWorldWithEnvironment(environment: World.Environment): World? {
return worlds.firstOrNull { it.environment == environment }
}
fun addGameEvent(vararg events: GameEvent) {
gameEvents.addAll(Arrays.asList(*events))
}
val host: Player
get() = Bukkit.getPlayer(hostUuid)
fun start() {
gameState = GameState.STARTING
val finalHeal = GameEvent("Final Heal", finalHealTime, object : GameEventRunnable(this) {
override fun run() {
Bukkit.getOnlinePlayers().forEach { player -> player.health = player.maxHealth }
CoreUtils.broadcast(Core.PREFIX + "Final Heal has been given. This is the FINAL heal. Do not ask for more.")
}
})
val pvp = GameEvent("PvP", pvpTicks, object : GameEventRunnable(this) {
override fun run() {
for (world in worlds) {
world.pvp = true
world.setGameRuleValue("doMobSpawning", "true")
}
}
})
val starting = GameEvent("Starting in", gameStartTicks, object : GameEventRunnable(this) {
override fun run() {
gameTicks = 0L
addGameEvent(finalHeal, pvp)
if (isBorderShrink)
addGameEvent(BorderShrinkGameEvent(meetupTicks, instance))
for (player in Bukkit.getOnlinePlayers()) {
player.health = player.maxHealth
player.foodLevel = 20
player.saturation = 20f
player.level = 0
player.exp = 0f
player.totalExperience = 0
player.closeInventory()
player.inventory.clear()
player.inventory.armorContents = null
player.gameMode = GameMode.SURVIVAL
player.activePotionEffects.forEach { potionEffect -> player.removePotionEffect(potionEffect.type) }
}
for (world in worlds) {
for (entity in world.entities) {
if (entity is Item || entity is Monster) {
entity.remove()
}
}
world.pvp = false
world.difficulty = Difficulty.HARD
world.time = 20
world.setSpawnFlags(false, false)
}
Bukkit.getOnlinePlayers().forEach { player -> gamePlayerManager.addGamePlayers(GamePlayer(player.uniqueId)) }
val players = ArrayList<Player>()
gamePlayerManager.aliveGamePlayers
.filter { gamePlayer -> gamePlayer.player != null }
.forEach { gamePlayer -> players.add(gamePlayer.player) }
scenarioManager.giveStartingItems(players)
gameState = GameState.RUNNING
Bukkit.getPluginManager().callEvent(GameStartEvent(instance))
}
})
addGameEvent(starting)
GameTimer().runTaskTimer(plugin, 0, 1)
if (gameType === GameType.RECORDED)
EpisodeTimerTask()
}
val nextEvent: GameEvent?
get() {
val events = gameEvents
val times = HashMap<GameEvent, Long>()
events.forEach { gameEvent -> times.put(gameEvent, gameEvent.time) }
var nextEvent: GameEvent? = null
var nextEventTime: Long = 999999999999999999L
for (event in times.keys) {
if (event.time < nextEventTime) {
nextEvent = event
nextEventTime = event.time
}
}
return nextEvent
}
fun getNextBorderRadius(world: World): Int {
return Math.round(world.worldBorder.size / 2 * .75).toInt()
}
private inner class GameTimer : BukkitRunnable() {
override fun run() {
val nextEvent = nextEvent
if (nextEvent != null) {
if (gameTicks!! % 20 == 0L) {
PacketUtils.sendAction(Core.HIGHLIGHTED_COLOR.toString() + ChatColor.BOLD.toString() + WordUtils.capitalizeFully(nextEvent.name) + Core.EXTRA_COLOR + " » " + Core.HIGHLIGHTED_COLOR + CoreUtils.formatTicks(nextEvent.time - gameTicks!!))
}
if (gameTicks >= nextEvent.time) {
nextEvent.runnable!!.run()
gameEvents.remove(nextEvent)
}
}
gameTicks++
}
}
private inner class BorderShrinkGameEvent(time: Long, game: Game) : GameEvent("Border Shrink", time, object : GameEventRunnable(game) {
override fun run() {
for (world in worlds) {
val wb = world.worldBorder
val radius = Math.round(wb.size / 2).toInt()
val newRadius = Math.round(wb.size / 2 * .75).toInt()
if (newRadius < 50)
wb.size = 100.0
else
wb.size = (newRadius * 2).toDouble()
CoreUtils.broadcast(Core.PREFIX + "The border has shrunk from " + radius + " to " + Math.round(wb.size / 2).toInt() + "!")
if (wb.size > 100) {
game.addGameEvent(BorderShrinkGameEvent(CoreUtils.ticksPerSecond * 5 + game.gameTicks!!, game))
}
}
}
})
private inner class EpisodeTimerTask : BukkitRunnable() {
private var ticks: Long = 0
init {
ticks = episodeLength
}
override fun run() {
if (ticks <= 0) {
cancel()
CoreUtils.broadcast(Core.PREFIX + "End of episode " + episode + ". Start episode " + episode + 1)
episode++
return
}
ticks--
}
}
fun stop() {
scenarioManager.disableAll()
Bukkit.getPluginManager().callEvent(GameStopEvent(this))
plugin.game = Game(plugin)
}
}
Game Setting Manager
package me.darkpaladin.uhc.game.gameSettings
import me.darkpaladin.core.Core
import me.darkpaladin.uhc.game.Game
import org.bukkit.Bukkit
import org.bukkit.event.Listener
import java.util.ArrayList
import java.util.Arrays
import java.util.stream.Collectors
/**
* Created by caleb on 5/6/17.
*/
class GameSettingsManager(game: Game) {
private val gameSettings = ArrayList<GameSetting>()
init {
addGameSettings(
FriendlyFireGameSetting(game),
NotchApplesGameSetting(),
DoubleArrowsGameSetting()
)
}
fun getGameSettings(): List<GameSetting> {
return gameSettings
}
val toggleableGameSettings: List<ToggleableGameSetting>
get() {
val settings = ArrayList<ToggleableGameSetting>()
for (setting in getGameSettings())
if (setting is ToggleableGameSetting)
settings.add(setting)
return settings
}
fun addGameSettings(vararg gameSettings: GameSetting) {
this.gameSettings.addAll(Arrays.asList(*gameSettings))
for(setting in gameSettings)
Bukkit.getPluginManager().registerEvents(setting as Listener, Core.instance)
}
fun getGameSetting(name: String): GameSetting {
return gameSettings.stream()
.filter { gameSetting -> gameSetting.name.equals(name, ignoreCase = true) }
.collect(Collectors.toList<GameSetting>())[0]
}
}

Answer 1

On line 43 of the GameSettingsManager:
fun addGameSettings(vararg gameSettings: GameSetting) {
this.gameSettings.addAll(Arrays.asList(*gameSettings))
for(setting in gameSettings) //line 43 is the one below this
Bukkit.getPluginManager().registerEvents(setting as Listener, Core.instance)
}
One of your setting objects that is being passed into Bukkit.getPluginManager() is null.
Or Core.Instance is null.
One other possibility is that the object being returned by getPluginManager() has an unitialized variable inside it that is being referenced in the registerEvents() function.
But the most likely case is that one of your setting objects is null or Core.Instance is null.
Edit
https://github.com/Bukkit/Bukkit/blob/master/src/main/java/org/bukkit/plugin/SimplePluginManager.java
Here is the registerEvents() function from the SimplePluginManager in the bukkit library that gets run:
public void registerEvents(Listener listener, Plugin plugin) {
if (!plugin.isEnabled()) {
//the next line is 523
throw new IllegalPluginAccessException("Plugin attempted to register " + listener + " while not enabled");
}
for (Map.Entry<Class<? extends Event>, Set<RegisteredListener>> entry : plugin.getPluginLoader().createRegisteredListeners(listener, plugin).entrySet()) {
getEventListeners(getRegistrationClass(entry.getKey())).registerAll(entry.getValue());
}
}
According to your stack trace line 523 is the one throwing the null pointer exception. So something there is null. The listener variable is coming from your gameSettings array though.
Looking at your code there really shouldn't be a null in that gameSettings varargs array. But the function that throws the error is saying otherwise. It would be a good idea to debug to that location or do a println as your looping through the gameSettings array to verify that none of it is null.