Events

Events Skill — Waterfall

Purpose

Reference this skill when handling events in a Waterfall (BungeeCord) proxy plugin. Waterfall's event system resembles Bukkit's @EventHandler pattern but uses BungeeCord-specific event classes.

When to Use This Skill

• Responding to player login, server switch, or disconnect events at the proxy level
• Intercepting chat at the proxy
• Implementing ban checks or authentication before players join the network

API Quick Reference

Class / Method	Purpose	Notes
Listener	Marker interface for BungeeCord event listeners	net.md_5.bungee.api.plugin.Listener
@EventHandler	Marks event handler method	net.md_5.bungee.event.EventHandler
EventPriority	Controls order: LOWEST → LOW → NORMAL → HIGH → HIGHEST	net.md_5.bungee.event.EventPriority
PluginManager#registerListener(Plugin, Listener)	Register all handlers in a listener
PostLoginEvent	Player fully connected to proxy	net.md_5.bungee.api.event.PostLoginEvent
LoginEvent	Before player is authenticated	Cancellable; set reason to kick
PlayerDisconnectEvent	Player left the proxy
ServerConnectedEvent	Player connected to a backend
ServerSwitchEvent	Player switched to a different backend
ChatEvent	Player sent a chat message	Cancellable
PluginMessageEvent	Plugin message received at proxy
ProxiedPlayer	BungeeCord player handle	net.md_5.bungee.api.connection.ProxiedPlayer

Code Pattern

package com.yourorg.waterfallplugin.listeners;

import net.md_5.bungee.api.ProxyServer;
import net.md_5.bungee.api.chat.TextComponent;
import net.md_5.bungee.api.connection.ProxiedPlayer;
import net.md_5.bungee.api.event.ChatEvent;
import net.md_5.bungee.api.event.LoginEvent;
import net.md_5.bungee.api.event.PlayerDisconnectEvent;
import net.md_5.bungee.api.event.PostLoginEvent;
import net.md_5.bungee.api.event.ServerConnectedEvent;
import net.md_5.bungee.api.plugin.Listener;
import net.md_5.bungee.api.plugin.Plugin;
import net.md_5.bungee.event.EventHandler;
import net.md_5.bungee.event.EventPriority;

import java.util.logging.Logger;

public class ConnectionListener implements Listener {

    private final Plugin plugin;
    private final Logger logger;

    public ConnectionListener(Plugin plugin) {
        this.plugin = plugin;
        this.logger = plugin.getLogger();
    }

    // Fires before login — kick players early
    @EventHandler(priority = EventPriority.NORMAL)
    public void onLogin(LoginEvent event) {
        // event.getConnection() gives InboundConnection (no player yet)
        String name = event.getConnection().getName();

        if (isNetworkBanned(name)) {
            // BungeeCord uses legacy chat components
            event.setCancelled(true);
            event.setCancelReason(new TextComponent("§cYou are banned from this network."));
        }
    }

    // Player fully connected to the proxy
    @EventHandler(priority = EventPriority.NORMAL)
    public void onPostLogin(PostLoginEvent event) {
        ProxiedPlayer player = event.getPlayer();
        logger.info(player.getName() + " (" + player.getUniqueId() + ") joined the network.");

        // Broadcast in BungeeCord style (legacy chat)
        ProxyServer.getInstance().broadcast(
            new TextComponent("§a» " + player.getName() + " joined the network.")
        );
    }

    // Player connected to a backend server
    @EventHandler
    public void onServerConnected(ServerConnectedEvent event) {
        ProxiedPlayer player = event.getPlayer();
        String serverName = event.getServer().getInfo().getName();
        logger.info(player.getName() + " connected to " + serverName);
    }

    // Player disconnected from the proxy
    @EventHandler
    public void onDisconnect(PlayerDisconnectEvent event) {
        ProxiedPlayer player = event.getPlayer();
        logger.info(player.getName() + " disconnected.");
    }

    // Chat event (fires at proxy level for all messages)
    @EventHandler(priority = EventPriority.NORMAL)
    public void onChat(ChatEvent event) {
        if (event.isCommand()) return;   // Skip commands

        String message = event.getMessage();
        if (containsProfanity(message)) {
            event.setCancelled(true);
            if (event.getSender() instanceof ProxiedPlayer player) {
                player.sendMessage(new TextComponent("§cYour message was blocked."));
            }
        }
    }

    private boolean isNetworkBanned(String name) { return false; }
    private boolean containsProfanity(String msg) { return false; }
}

Register listener in main class:

@Override
public void onEnable() {
    getProxy().getPluginManager().registerListener(this, new ConnectionListener(this));
}

Common Pitfalls

• Using Bukkit @EventHandler annotation: The BungeeCord annotation is net.md_5.bungee.event.EventHandler, NOT org.bukkit.event.EventHandler. Using the wrong import means handlers are silently ignored.

• Using Adventure components on Waterfall without the adapter: Waterfall doesn't natively support Adventure. Use legacy TextComponent and ChatColor OR add the adventure-platform-bungeecord adapter to your shaded JAR.

• Cancelling PlayerDisconnectEvent: This event is NOT cancellable. You cannot prevent a disconnect at this stage.

• Using ServerConnectedEvent vs ServerSwitchEvent: ServerConnectedEvent fires when a player joins a backend (initial or switch). ServerSwitchEvent fires after the switch is complete and provides the from server. For most use cases, ServerConnectedEvent is preferred.

Version Notes

• Waterfall 1.21: Event API is unchanged from older BungeeCord versions. All events in net.md_5.bungee.api.event.* are available.
• LoginEvent is async in BungeeCord — blocking in its handler delays login for that player.

Related Skills

• ../OVERVIEW.md — Waterfall platform setup
• ../messaging/SKILL.md — Plugin messaging
• ../../velocity/events/SKILL.md — Equivalent Velocity events