# Generate Proxy Event Listener > 為 Velocity proxy plugin 產生 @Subscribe 事件監聽器，支援連線事件（LoginEvent, PostLoginEvent, DisconnectEvent）和伺服器切換事件（ServerConnectedEvent, PlayerChooseInitialServerEvent）。當使用者說「監聽 Velocity 事件」、「proxy event listener」、「login event」、「server switch」時自動應用。 - Skill: `mrpippi/generate-proxy-event-listener` (Agent Skill) - Install (CLI): `npx skillmds@latest add mrpippi/generate-proxy-event-listener` - Raw SKILL.md: https://api.skillmd.com/api/skills/mrpippi/generate-proxy-event-listener/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: MrPippi (https://skillmd.com/u/mrpippi) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/mrpippi/generate-proxy-event-listener --- # Generate Proxy Event Listener / 產生 Velocity 事件監聽器 ## 技能名稱 / Skill Name generate-proxy-event-listener ## 目的 / Purpose 依使用者指定的 Velocity 事件清單，產生完整的 `@Subscribe` 事件監聽器類別，含 PostOrder、ResultedEvent 處理、正確的 Guice 注入範例。 ## 觸發條件 / Triggers - 「監聽 Velocity 事件」 - 「proxy event listener」 - 「@Subscribe」 - 「LoginEvent / PostLoginEvent / DisconnectEvent」 - 「server switch event」 - 「PlayerChooseInitialServerEvent」 ## 輸入參數 / Inputs | 參數 | 範例 | 說明 | |------|------|------| | `listener_name` | `ConnectionListener` | 監聽器類別名稱 | | `events` | `["PostLoginEvent", "DisconnectEvent", "ServerConnectedEvent"]` | 要監聽的事件列表 | | `plugin_package` | `com.mynetwork.myplugin` | 插件套件名稱 | | `deny_on_login` | `false` | 是否需要在 LoginEvent 拒絕連線（ResultedEvent 模式） | ## 輸出產物 / Outputs - `{ListenerName}.java` — 完整的事件監聽器類別 ## 代碼範本 / Code Template ```java package {plugin_package}.listeners; import com.velocitypowered.api.event.PostOrder; import com.velocitypowered.api.event.ResultedEvent; import com.velocitypowered.api.event.Subscribe; import com.velocitypowered.api.event.connection.DisconnectEvent; import com.velocitypowered.api.event.connection.LoginEvent; import com.velocitypowered.api.event.connection.PostLoginEvent; import com.velocitypowered.api.event.player.PlayerChooseInitialServerEvent; import com.velocitypowered.api.event.player.ServerConnectedEvent; import com.velocitypowered.api.proxy.Player; import com.velocitypowered.api.proxy.ProxyServer; import com.velocitypowered.api.proxy.server.RegisteredServer; import net.kyori.adventure.text.Component; import net.kyori.adventure.text.format.NamedTextColor; import org.slf4j.Logger; import java.util.Optional; public class ConnectionListener { private final ProxyServer server; private final Logger logger; public ConnectionListener(ProxyServer server, Logger logger) { this.server = server; this.logger = logger; } /** * Fires before the player is fully logged in — can deny the connection. * This is a ResultedEvent: always call event.setResult() when making decisions. */ @Subscribe(order = PostOrder.NORMAL) public void onLogin(LoginEvent event) { String username = event.getPlayer().getUsername(); if (isBanned(username)) { // Deny the connection with a reason event.setResult(ResultedEvent.ComponentResult.denied( Component.text("You are banned from this network.") .color(NamedTextColor.RED) )); return; } // Allow (default result — only set explicitly when needed) } /** * Fires after the player has fully connected to the proxy. * Safe place to load player data, broadcast join messages, etc. */ @Subscribe(order = PostOrder.NORMAL) public void onPostLogin(PostLoginEvent event) { Player player = event.getPlayer(); logger.info("{} ({}) connected to the proxy.", player.getUsername(), player.getUniqueId()); // Network-wide join broadcast server.getAllPlayers().forEach(p -> p.sendMessage(Component.text("→ ") .color(NamedTextColor.GREEN) .append(Component.text(player.getUsername() + " joined the network.") .color(NamedTextColor.WHITE))) ); } /** * Fires when Velocity selects the initial backend server for a connecting player. * Override the target server by calling event.setInitialServer(). */ @Subscribe(order = PostOrder.NORMAL) public void onChooseInitialServer(PlayerChooseInitialServerEvent event) { Optional lobby = server.getServer("lobby"); lobby.ifPresent(event::setInitialServer); } /** * Fires after the player successfully switches to a backend server. */ @Subscribe(order = PostOrder.NORMAL) public void onServerConnected(ServerConnectedEvent event) { Player player = event.getPlayer(); String targetServer = event.getServer().getServerInfo().getName(); String previousServer = event.getPreviousServer() .map(s -> s.getServerInfo().getName()) .orElse("none"); logger.info("{} switched from {} to {}", player.getUsername(), previousServer, targetServer); } /** * Fires when the player disconnects from the proxy entirely. */ @Subscribe(order = PostOrder.NORMAL) public void onDisconnect(DisconnectEvent event) { logger.info("{} disconnected ({}).", event.getPlayer().getUsername(), event.getLoginStatus()); } private boolean isBanned(String username) { // Replace with your ban storage check return false; } } ``` **Register the listener in your main plugin class:** ```java @Subscribe public void onProxyInitialize(ProxyInitializeEvent event) { server.getEventManager().register(this, new ConnectionListener(server, logger)); } ``` ## 事件速查表 / Event Quick Reference | Event | 套件 | 觸發時機 | ResultedEvent? | |-------|------|---------|----------------| | `PreLoginEvent` | `connection` | 最早階段，可拒絕（甚至在 UUID 查詢前） | ✅ | | `LoginEvent` | `connection` | UUID 確認後，可拒絕連線 | ✅ | | `PostLoginEvent` | `connection` | 完全連線後 | ❌ | | `DisconnectEvent` | `connection` | 玩家斷線（含未完全登入的情況） | ❌ | | `PlayerChooseInitialServerEvent` | `player` | 選擇初始後端伺服器 | ✅ | | `ServerPreConnectEvent` | `player` | 切換伺服器前，可拒絕 | ✅ | | `ServerConnectedEvent` | `player` | 切換伺服器完成後 | ❌ | | `KickedFromServerEvent` | `player` | 被後端伺服器踢出 | ✅ (可重導向) | | `PlayerChatEvent` | `player` | 玩家發送聊天訊息 | ✅ | | `CommandExecuteEvent` | `command` | 玩家執行指令 | ✅ | ## 失敗回退 / Fallback - 不要在 `@Subscribe` 方法中使用 `@EventHandler`（那是 Bukkit/Waterfall 的 annotation，會被 Velocity 靜默忽略）。 - `LoginEvent` 是 `ResultedEvent`：如果沒有呼叫 `setResult()`，預設結果是允許（allow）。 - Velocity 事件全部在 async thread pool 執行，不要呼叫 `Thread.sleep()` 或執行 blocking IO。 - 若需要在事件處理完成前等待 async 工作，回傳 `EventTask.async(() -> {...})`。