Solved ConcurrentModificationException

Code:

[22:10:14 ERROR]: null
org.bukkit.command.CommandException: Unhandled exception executing command 'sas'
in plugin SticksAndStones v1.0
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[cra
ftbukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
        at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:18
0) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
        at org.bukkit.craftbukkit.v1_7_R3.CraftServer.dispatchCommand(CraftServe
r.java:703) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
        at net.minecraft.server.v1_7_R3.PlayerConnection.handleCommand(PlayerCon
nection.java:955) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
        at net.minecraft.server.v1_7_R3.PlayerConnection.a(PlayerConnection.java
:817) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
        at net.minecraft.server.v1_7_R3.PacketPlayInChat.a(PacketPlayInChat.java
:28) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
        at net.minecraft.server.v1_7_R3.PacketPlayInChat.handle(PacketPlayInChat
.java:47) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
        at net.minecraft.server.v1_7_R3.NetworkManager.a(NetworkManager.java:157
) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
        at net.minecraft.server.v1_7_R3.ServerConnection.c(SourceFile:134) [craf
tbukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
        at net.minecraft.server.v1_7_R3.MinecraftServer.v(MinecraftServer.java:6
67) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
        at net.minecraft.server.v1_7_R3.DedicatedServer.v(DedicatedServer.java:2
60) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
        at net.minecraft.server.v1_7_R3.MinecraftServer.u(MinecraftServer.java:5
58) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
        at net.minecraft.server.v1_7_R3.MinecraftServer.run(MinecraftServer.java
:469) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
        at net.minecraft.server.v1_7_R3.ThreadServerApplication.run(SourceFile:6
28) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
Caused by: java.util.ConcurrentModificationException
        at java.util.ArrayList$Itr.checkForComodification(Unknown Source) ~[?:1.
7.0_25]
        at java.util.ArrayList$Itr.next(Unknown Source) ~[?:1.7.0_25]
        at me.icyrelic.com.Arenas.ArenaManager.endArena(ArenaManager.java:200) ~
[?:?]
        at me.icyrelic.com.Commands.command_sas.onCommand(command_sas.java:351)
~[?:?]
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[cra
ftbukkit.jar:git-Bukkit-1.7.2-R0.3-66-g43d8943-b3078jnks]
        ... 13 more
>

End arena method

Code:java

        public void endArena(String arenaName) {
 
            if (getArena(arenaName) != null) {
 
                Arena arena = getArena(arenaName);
                arena.sendMessage(ChatColor.GOLD + "The arena has ended");
                arena.setInGame(false);
 
                for (String name: arena.getPlayers()) {
 
                    @SuppressWarnings("deprecation")
                    Player player = Bukkit.getPlayer(name);
                    player.teleport(arena.getEndLocation());
                    // Restore inventory //
 
                    player.getInventory().clear();
                    player.setHealth(player.getMaxHealth());
                    player.setFireTicks(0);
 
                    arena.getPlayers().remove(player.getName());
 
                }
 
 
            }
        }

end arena Line 200

Code:java

for (String name: arena.getPlayers()) {

command_sas line 351

Code:java

ArenaManager.getManager().endArena(arenaName);

if u need any more code let me know

Solved

Found this thread and it helped me fix my error

https://forums.bukkit.org/threads/solved-caused-by-java-util-concurrentmodificationexception.84419/

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

Icyrelic Throws a http://docs.oracle.com/javase/7/docs/api/java/util/ConcurrentModificationException.html
You are trying to remove a Player while you are still iterating over the Collection of Players, and most implementations don't allow this. Simple research would lead you to why this happened and possible fixes.
Simply remove all that you want to remove after iterating over the collection.