1.8.8 List randomly becoming empty

Code (Java):

@Getter
@RequiredArgsConstructor
public class War {

    private final List<UUID> teamOne;
    private final List<UUID> teamTwo;
    private final WarType warType;
    private final List<UUID> teamOneAlive;
    private final List<UUID> teamTwoAlive;
    @Nullable
    private final Island winnerIsland;
}

Code (Java):

private void tryPrepareForWar(Set<Queue> queueSet) {
        for (Queue inQueue : queueSet) {
            if (inQueue.getUuid().equals(getPlayer().getUniqueId())) continue;
            getTeamMates().add(getPlayer().getUniqueId());
            List<UUID> teamTwo = inQueue.getTeamMates();
            teamTwo.add(inQueue.getUuid());
            ShardWars.getPlayerQueueManagerMap().get(inQueue.getUuid()).removeFromQueue();
            removeFromQueue();
            new WarManager(new War(getTeamMates(), teamTwo, getWarType(), getTeamMates(), teamTwo, null)).startWar();
            break;
        }
    }

Code (Java):

WarManager warManager = ShardWars.getPlayerWarManagerMap().get(player.getUniqueId());
        War war = warManager.getWar();
        if (war.getTeamOneAlive().isEmpty()) {
            warManager.endWar(Core.getInstance().skyblockManager.getIsland(war.getTeamTwo().get(0)),
                    Core.getInstance().skyblockManager.getIsland(war.getTeamOne().get(0)));
            return;
        }
        if (war.getTeamTwoAlive().isEmpty()) {
            warManager.endWar(Core.getInstance().skyblockManager.getIsland(war.getTeamOne().get(0)),
                    Core.getInstance().skyblockManager.getIsland(war.getTeamTwo().get(0)));
            return;
        }

I'm using the Spigot API and I'm creating a player verse player type plugin. I'm using lombok for getters and constructors. War#getTeamOne() and War#getTeamTwo() randomly become empty. I print the lists throughout the code and it contains a value, but then just before I do WarManager#endWar(), the list is empty. Nowhere in my project do I remove from either of those lists. Any idea why that is? If you need to see more code, lmk.

 

Yeh I've done that, and there's not much I can debug.

 

Code (Java):

public void removeFromQueue() {
        switch (getWarType()) {
            case ONEVONE:
                ShardWars.getOneVerseOneQueues().remove(ShardWars.getPlayerQueueMap().get(getPlayer().getUniqueId()));
            case TWOVTWO:
                ShardWars.getTwoVerseTwoQueues().remove(ShardWars.getPlayerQueueMap().get(getPlayer().getUniqueId()));
            case FOURVFOUR:
                ShardWars.getFourVerseFourQueues().remove(ShardWars.getPlayerQueueMap().get(getPlayer().getUniqueId()));
        }
    }

 

Uh yes?

 

Could you explain what you mean? Like this?

Code (Java):

for (Iterator<Queue> iterator = queueSet.iterator(); iterator.hasNext(); ) {
            Queue inQueue = iterator.next();

 

How would I do that?

 

Code (Java):

ShardWars.getPlayerQueueManagerMap().get(inQueue.getUuid()).removeFromQueue();
            iterator.remove();

?

 

How would I do that? Show me the actual code s oI understand.

 

I get a ConcurrentModificationException

 

Code (Text):

private void tryPrepareForWar(Set<Queue> queueSet) {
        for (Iterator<Queue> iterator = queueSet.iterator(); iterator.hasNext(); ) {
            Queue inQueue = iterator.next();
            if (inQueue.getUuid().equals(getPlayer().getUniqueId())) continue;
            List<UUID> teamOne = getTeamMates();
            teamOne.add(getPlayer().getUniqueId());
            List<UUID> teamTwo = inQueue.getTeamMates();
            teamTwo.add(inQueue.getUuid());
            WarType warType = getWarType();
            ShardWars.getPlayerQueueManagerMap().get(inQueue.getUuid()).removeFromQueue();
            iterator.remove();
            new WarManager(new War(teamOne, teamTwo, warType, teamOne, teamTwo, null)).startWar();
            break;
        }
    }