Can You Tell Me What's Wrong Here?

I am creating a minigame plugin. Its been going fine so far, but I've become stumped on this part. I am trying to get a random player from online players. That returns a Player name cannot be null error. I am also trying to get a list of words from a config it gave me a mapping values aren't allowed here error. (I would show you my console but not quite sure how to copy it....)

Code:java

 if (command.getName().equalsIgnoreCase("creategame")){
                  Player random = Bukkit.getOnlinePlayers()[new Random().nextInt(Bukkit.getOnlinePlayers().length)];
                      Location loc = new Location(
                                  Bukkit.getServer().getWorld(plugin.getConfig().getString("Loc.world")),
                                  plugin.getConfig().getDouble("Loc.x"),
                                  plugin.getConfig().getDouble("Loc.y"),
                                  plugin.getConfig().getDouble("Loc.z"));
                                  random.teleport((loc));
                                  List<?> words = plugin.getConfig().getList("Words");
                                  String word = (String) words.get(new Random().nextInt(words.size()));
                                  sender.sendMessage(word);
                  sender.sendMessage("New game started! Waiting for players...");
              }
            } else {
              sender.sendMessage("Only players can run this command!");
              return false;
            }
            return false;
    }

 

Make sure that there is actually at least one player online. Otherwise player will be null.
P.S. Give us full error report and the line on which the error occurs, otherwise we won't be able to help you with non-obvious errors

 

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[SEVERE] Cannot load plugins\Blocktionary\config.yml
org.bukkit.configuration.InvalidConfigurationException: mapping values are not allowed here
in "<string>", line 11, column 30:
z: -123.43599741635238Words: hi hello
^

at org.bukkit.configuration.file.YamlConfiguration.loadFromString(YamlConfiguration.java:55)
at org.bukkit.configuration.file.FileConfiguration.load(FileConfiguration.java:138)
at org.bukkit.configuration.file.FileConfiguration.load(FileConfiguration.java:105)
at org.bukkit.configuration.file.YamlConfiguration.loadConfiguration(YamlConfiguration.java:175)
at org.bukkit.plugin.java.JavaPlugin.reloadConfig(JavaPlugin.java:117)
at org.bukkit.plugin.java.JavaPlugin.getConfig(JavaPlugin.java:111)
at com.gmail.marbolgames.CommandExecutorClass.onCommand(CommandExecutorClass.java:47)
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44)
at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:189)
at org.bukkit.craftbukkit.v1_6_R2.CraftServer.dispatchCommand(CraftServer.java:523)
at net.minecraft.server.v1_6_R2.PlayerConnection.handleCommand(PlayerConnection.java:964)
at net.minecraft.server.v1_6_R2.PlayerConnection.chat(PlayerConnection.java:882)
at net.minecraft.server.v1_6_R2.PlayerConnection.a(PlayerConnection.java:839)
at net.minecraft.server.v1_6_R2.Packet3Chat.handle(SourceFile:49)
at net.minecraft.server.v1_6_R2.NetworkManager.b(NetworkManager.java:296)
at net.minecraft.server.v1_6_R2.PlayerConnection.e(PlayerConnection.java:118)
at net.minecraft.server.v1_6_R2.ServerConnection.b(SourceFile:37)
at net.minecraft.server.v1_6_R2.DedicatedServerConnection.b(SourceFile:30)
at net.minecraft.server.v1_6_R2.MinecraftServer.t(MinecraftServer.java:590)
at net.minecraft.server.v1_6_R2.DedicatedServer.t(DedicatedServer.java:226)
at net.minecraft.server.v1_6_R2.MinecraftServer.s(MinecraftServer.java:486)
at net.minecraft.server.v1_6_R2.MinecraftServer.run(MinecraftServer.java:419)
at net.minecraft.server.v1_6_R2.ThreadServerApplication.run(SourceFile:582)
Caused by: mapping values are not allowed here
in "<string>", line 11, column 30:
z: -123.43599741635238Words: hi hello
^

at org.yaml.snakeyaml.scanner.ScannerImpl.fetchValue(ScannerImpl.java:733)
at org.yaml.snakeyaml.scanner.ScannerImpl.fetchMoreTokens(ScannerImpl.java:305)
at org.yaml.snakeyaml.scanner.ScannerImpl.checkToken(ScannerImpl.java:179)
at org.yaml.snakeyaml.parser.ParserImpl$ParseBlockMappingKey.produce(ParserImpl.java:563)
at org.yaml.snakeyaml.parser.ParserImpl.peekEvent(ParserImpl.java:161)
at org.yaml.snakeyaml.parser.ParserImpl.checkEvent(ParserImpl.java:146)
at org.yaml.snakeyaml.composer.Composer.composeMappingNode(Composer.java:230)
at org.yaml.snakeyaml.composer.Composer.composeNode(Composer.java:160)
at org.yaml.snakeyaml.composer.Composer.composeMappingNode(Composer.java:237)
at org.yaml.snakeyaml.composer.Composer.composeNode(Composer.java:160)
at org.yaml.snakeyaml.composer.Composer.composeDocument(Composer.java:123)
at org.yaml.snakeyaml.composer.Composer.getSingleNode(Composer.java:106)
at org.yaml.snakeyaml.constructor.BaseConstructor.getSingleData(BaseConstructor.java:121)
at org.yaml.snakeyaml.Yaml.loadFromReader(Yaml.java:480)
at org.yaml.snakeyaml.Yaml.load(Yaml.java:399)
at org.bukkit.configuration.file.YamlConfiguration.loadFromString(YamlConfiguration.java:53)
... 22 more
2013-09-02 16:09:06 [SEVERE] null
org.bukkit.command.CommandException: Unhandled exception executing command 'creategame' in plugin Blocktionary v1.0
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46)
at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:189)
at org.bukkit.craftbukkit.v1_6_R2.CraftServer.dispatchCommand(CraftServer.java:523)
at net.minecraft.server.v1_6_R2.PlayerConnection.handleCommand(PlayerConnection.java:964)
at net.minecraft.server.v1_6_R2.PlayerConnection.chat(PlayerConnection.java:882)
at net.minecraft.server.v1_6_R2.PlayerConnection.a(PlayerConnection.java:839)
at net.minecraft.server.v1_6_R2.Packet3Chat.handle(SourceFile:49)
at net.minecraft.server.v1_6_R2.NetworkManager.b(NetworkManager.java:296)
at net.minecraft.server.v1_6_R2.PlayerConnection.e(PlayerConnection.java:118)
at net.minecraft.server.v1_6_R2.ServerConnection.b(SourceFile:37)
at net.minecraft.server.v1_6_R2.DedicatedServerConnection.b(SourceFile:30)
at net.minecraft.server.v1_6_R2.MinecraftServer.t(MinecraftServer.java:590)
at net.minecraft.server.v1_6_R2.DedicatedServer.t(DedicatedServer.java:226)
at net.minecraft.server.v1_6_R2.MinecraftServer.s(MinecraftServer.java:486)
at net.minecraft.server.v1_6_R2.MinecraftServer.run(MinecraftServer.java:419)
at net.minecraft.server.v1_6_R2.ThreadServerApplication.run(SourceFile:582)
Caused by: java.lang.IllegalArgumentException: Name cannot be null
at org.apache.commons.lang.Validate.notNull(Validate.java:203)
at org.bukkit.craftbukkit.v1_6_R2.CraftServer.getWorld(CraftServer.java:819)
at com.gmail.marbolgames.CommandExecutorClass.onCommand(CommandExecutorClass.java:47)
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44)
... 15 more

 

The problem is that your config is misformatted and cannot be read. This causes plugin.getConfig().getString("Loc.world") to return null, and thus for you to attempt and fail to Bukkit.getServer().getWorld(null)

 

Ok thanks it teleports me fine now but I still get an internal error. Here is the log:

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2013-09-02 19:38:23 [INFO] mattrick16 issued server command: /specspawn
2013-09-02 19:38:31 [INFO] mattrick16 issued server command: /creategame
2013-09-02 19:38:31 [SEVERE] null
org.bukkit.command.CommandException: Unhandled exception executing command 'creategame' in plugin Blocktionary v1.0
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46)
at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:189)
at org.bukkit.craftbukkit.v1_6_R2.CraftServer.dispatchCommand(CraftServer.java:523)
at net.minecraft.server.v1_6_R2.PlayerConnection.handleCommand(PlayerConnection.java:964)
at net.minecraft.server.v1_6_R2.PlayerConnection.chat(PlayerConnection.java:882)
at net.minecraft.server.v1_6_R2.PlayerConnection.a(PlayerConnection.java:839)
at net.minecraft.server.v1_6_R2.Packet3Chat.handle(SourceFile:49)
at net.minecraft.server.v1_6_R2.NetworkManager.b(NetworkManager.java:296)
at net.minecraft.server.v1_6_R2.PlayerConnection.e(PlayerConnection.java:118)
at net.minecraft.server.v1_6_R2.ServerConnection.b(SourceFile:37)
at net.minecraft.server.v1_6_R2.DedicatedServerConnection.b(SourceFile:30)
at net.minecraft.server.v1_6_R2.MinecraftServer.t(MinecraftServer.java:590)
at net.minecraft.server.v1_6_R2.DedicatedServer.t(DedicatedServer.java:226)
at net.minecraft.server.v1_6_R2.MinecraftServer.s(MinecraftServer.java:486)
at net.minecraft.server.v1_6_R2.MinecraftServer.run(MinecraftServer.java:419)
at net.minecraft.server.v1_6_R2.ThreadServerApplication.run(SourceFile:582)
Caused by: java.lang.NullPointerException
at com.gmail.marbolgames.CommandExecutorClass.onCommand(CommandExecutorClass.java:53)
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44)
... 15 more

 

mattrick16
The list should not be full of ? Elements, use getStringlist or getIntegerList or something. Also, plugin may be null.

 

Sorry for asking to be spoon-fed code but do you think you can give me an example. I changed getList to getString list. and my List<?> variable to List<String> and it still doesn't work....

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2013-09-02 19:52:08 [INFO] [Blocktionary] Disabling Blocktionary v1.0
2013-09-02 19:52:08 [INFO] [Blocktionary] Loading Blocktionary v1.0
2013-09-02 19:52:08 [INFO] [Blocktionary] Enabling Blocktionary v1.0
2013-09-02 19:52:08 [INFO] Server permissions file permissions.yml is empty, ignoring it
2013-09-02 19:52:08 [INFO] CONSOLE: Reload complete.
2013-09-02 19:52:16 [INFO] mattrick16 issued server command: /creategame
2013-09-02 19:52:16 [SEVERE] null
org.bukkit.command.CommandException: Unhandled exception executing command 'creategame' in plugin Blocktionary v1.0
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46)
at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:189)
at org.bukkit.craftbukkit.v1_6_R2.CraftServer.dispatchCommand(CraftServer.java:523)
at net.minecraft.server.v1_6_R2.PlayerConnection.handleCommand(PlayerConnection.java:964)
at net.minecraft.server.v1_6_R2.PlayerConnection.chat(PlayerConnection.java:882)
at net.minecraft.server.v1_6_R2.PlayerConnection.a(PlayerConnection.java:839)
at net.minecraft.server.v1_6_R2.Packet3Chat.handle(SourceFile:49)
at net.minecraft.server.v1_6_R2.NetworkManager.b(NetworkManager.java:296)
at net.minecraft.server.v1_6_R2.PlayerConnection.e(PlayerConnection.java:118)
at net.minecraft.server.v1_6_R2.ServerConnection.b(SourceFile:37)
at net.minecraft.server.v1_6_R2.DedicatedServerConnection.b(SourceFile:30)
at net.minecraft.server.v1_6_R2.MinecraftServer.t(MinecraftServer.java:590)
at net.minecraft.server.v1_6_R2.DedicatedServer.t(DedicatedServer.java:226)
at net.minecraft.server.v1_6_R2.MinecraftServer.s(MinecraftServer.java:486)
at net.minecraft.server.v1_6_R2.MinecraftServer.run(MinecraftServer.java:419)
at net.minecraft.server.v1_6_R2.ThreadServerApplication.run(SourceFile:582)
Caused by: java.lang.IllegalArgumentException: n must be positive
at java.util.Random.nextInt(Unknown Source)
at com.gmail.marbolgames.CommandExecutorClass.onCommand(CommandExecutorClass.java:54)
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44)
... 15 more

EDIT: The plugin is not null it is declared at the beginning of my class.

 

mattrick16
You need to set plugin to a value. If its like

PHP:

ClassName plugin;

Then it's null. It's not initialized. You need a constructor called when registering the command executor to initialize the plugin variable.

 

Like this?

Code:java

public Blocktionary plugin;
 
public CommandExecutorClass(Blocktionary plugin){
this.plugin = plugin;
}

From what I see its something with a variable n being negative?

 

mattrick16
Is that what you did?

Edit: Whoops, didn't read the stack trace righ

 

Yeah thats what I did originally.

 

You're trying to select one player at random when no players are online.

 

No that part works fine it is a problem with getting a random word from a config. Besides I made sure that you cannot run from console.

 

Well what is line 54? Because that's where the problem is.
at com.gmail.marbolgames.CommandExecutorClass.onCommand(CommandExecutorClass.java:54)

 

Code:java

String word = (String) words.get(new Random().nextInt(words.size()));

This is the line.

 

well apparently your array words sometimes has a size of zero
http://forums.bukkit.org/threads/ho...ubleshoot-your-own-plugins-by-yourself.32457/

 

I understand that. I am asking if you know how to get a random word from a list off of a config.

 

assuming that your getStringList is correct, that's how you get a random word, but before attempting to get a random word you have to ensure that there is a random word to get.

 

I am sure but I think now its actually a problem with getWorld......

Code:

2013-09-03 19:22:40 [SEVERE] null
org.bukkit.command.CommandException: Unhandled exception executing command 'creategame' in plugin Blocktionary v1.0
    at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46)
    at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:189)
    at org.bukkit.craftbukkit.v1_6_R2.CraftServer.dispatchCommand(CraftServer.java:523)
    at net.minecraft.server.v1_6_R2.PlayerConnection.handleCommand(PlayerConnection.java:964)
    at net.minecraft.server.v1_6_R2.PlayerConnection.chat(PlayerConnection.java:882)
    at net.minecraft.server.v1_6_R2.PlayerConnection.a(PlayerConnection.java:839)
    at net.minecraft.server.v1_6_R2.Packet3Chat.handle(SourceFile:49)
    at net.minecraft.server.v1_6_R2.NetworkManager.b(NetworkManager.java:296)
    at net.minecraft.server.v1_6_R2.PlayerConnection.e(PlayerConnection.java:118)
    at net.minecraft.server.v1_6_R2.ServerConnection.b(SourceFile:37)
    at net.minecraft.server.v1_6_R2.DedicatedServerConnection.b(SourceFile:30)
    at net.minecraft.server.v1_6_R2.MinecraftServer.t(MinecraftServer.java:590)
    at net.minecraft.server.v1_6_R2.DedicatedServer.t(DedicatedServer.java:226)
    at net.minecraft.server.v1_6_R2.MinecraftServer.s(MinecraftServer.java:486)
    at net.minecraft.server.v1_6_R2.MinecraftServer.run(MinecraftServer.java:419)
    at net.minecraft.server.v1_6_R2.ThreadServerApplication.run(SourceFile:582)
Caused by: java.lang.IllegalArgumentException: Name cannot be null
    at org.apache.commons.lang.Validate.notNull(Validate.java:203)
    at org.bukkit.craftbukkit.v1_6_R2.CraftServer.getWorld(CraftServer.java:819)
    at com.gmail.marbolgames.CommandExecutorClass.onCommand(CommandExecutorClass.java:47)
    at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44)
    ... 15 more

This is if I set world to world.

 

You're on the right track, but really, http://forums.bukkit.org/threads/ho...ubleshoot-your-own-plugins-by-yourself.32457/. You need to be able to figure out errors like these if you want to be capable of writing plugins on your own.

 

Ok I get it. There is a problem on my config getWorld() method in my command executor class on line 47. I am trying to get a world from a config. How should I go about this?

 

It would be nice to see your config file and your whole class file (correct line numbers please), so that we can look at it and get the point where the world name turns null.

 

Caused by: java.lang.IllegalArgumentException: Name cannot be null
This is what getWorld(String name) is returning. So clearly, whatever you're doing to retrieve your world from your config is returning null, aka, not found. This can be because you've misspelled, misformatted, or omitted the proper config entry.

 

Ok I fixed it thanks!