实现了prefix功能（未测试）

pom.xml

@@ -70,6 +70,10 @@
           <id>lunadeer-repo</id>
           <url>https://ssl.lunadeer.cn:14454/repository/maven-snapshots/</url>
       </repository>
+      <repository>
+          <id>placeholderapi</id>
+          <url>https://repo.extendedclip.com/content/repositories/placeholderapi/</url>
+      </repository>
   </repositories>
 
     <dependencies>
@@ -90,5 +94,11 @@
             <version>1.7</version>
             <scope>provided</scope>
         </dependency>
+        <dependency>
+            <groupId>me.clip</groupId>
+            <artifactId>placeholderapi</artifactId>
+            <version>2.11.6</version>
+            <scope>provided</scope>
+        </dependency>
     </dependencies>
 </project>

src/main/java/cn/lunadeer/essentialsd/EssentialsD.java

@@ -38,7 +38,6 @@ public final class EssentialsD extends JavaPlugin {
         instance = this;
         new XLogger(instance);
         config = new ConfigManager(instance);
-        XLogger.setDebug(config.isDebug());
         new Notification(instance);
         database = new DatabaseManager(this,
                 DatabaseManager.TYPE.valueOf(config.getDbType().toUpperCase()),
@@ -51,6 +50,15 @@ public final class EssentialsD extends JavaPlugin {
         new Scheduler(this);
         tpManager = new TeleportManager();
 
+        if (config.getPrefixEnable()) {
+            if (Bukkit.getPluginManager().getPlugin("PlaceholderAPI") != null) {
+                Bukkit.getPluginManager().registerEvents(new ChatPrefixEvent(), this);
+            } else {
+                XLogger.warn("未找到 PlaceholderAPI 插件, 无法使用聊天前缀功能, 已自动关闭前缀功能");
+                config.setPrefixEnable(false);
+            }
+        }
+
         Bukkit.getPluginManager().registerEvents(new InvisibleItemFrameEvent(), this);
         Bukkit.getPluginManager().registerEvents(new ChairEvent(), this);
         Bukkit.getPluginManager().registerEvents(new ArmorStandHandsEvent(), this);

src/main/java/cn/lunadeer/essentialsd/events/ChatPrefixEvent.java

@@ -0,0 +1,19 @@
+package cn.lunadeer.essentialsd.events;
+
+import cn.lunadeer.essentialsd.EssentialsD;
+import io.papermc.paper.event.player.AsyncChatEvent;
+import me.clip.placeholderapi.PlaceholderAPI;
+import net.kyori.adventure.text.Component;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.Listener;
+
+public class ChatPrefixEvent implements Listener {
+
+    @EventHandler
+    public void onChat(AsyncChatEvent event) {
+        event.setCancelled(true);
+        String formated = PlaceholderAPI.setPlaceholders(event.getPlayer(), EssentialsD.config.getPrefixFormat());
+        EssentialsD.instance.getServer().sendMessage(Component.text(formated).append(event.message()));
+    }
+
+}

src/main/java/cn/lunadeer/essentialsd/managers/ConfigManager.java

@@ -23,6 +23,7 @@ public class ConfigManager {
         _plugin.reloadConfig();
         _file = _plugin.getConfig();
         _debug = _file.getBoolean("Debug", false);
+        XLogger.setDebug(isDebug());
         _check_update = _file.getBoolean("CheckUpdate", true);
         _exp_bottle_ratio = (float) _file.getDouble("ExpBottleRatio", 1.0);
         _combine_exp_orbs_enable = _file.getBoolean("CombineExpOrbs.Enable", false);
@@ -55,6 +56,44 @@ public class ConfigManager {
         _db_name = _file.getString("Database.Name", "dominion");
         _db_user = _file.getString("Database.User", "postgres");
         _db_pass = _file.getString("Database.Pass", "postgres");
+        _prefix_enable = _file.getBoolean("Prefix.Enable", true);
+        _prefix_format = _file.getString("Prefix.Format", "<%player_name%> ");
+        saveAll();  // save all to make sure all values are valid
+    }
+
+    private void saveAll() {
+        _file.set("Debug", _debug);
+        _file.set("CheckUpdate", _check_update);
+        _file.set("ExpBottleRatio", _exp_bottle_ratio);
+        _file.set("CombineExpOrbs.Enable", _combine_exp_orbs_enable);
+        _file.set("CombineExpOrbs.Radius", _combine_exp_orbs_radius);
+        _file.set("NoExpCoolDown", _no_exp_cool_down);
+        _file.set("ForceLoadChunks", _force_load_chunks);
+        _file.set("ChunkOperateDelay", _chunk_operate_delay);
+        _file.set("Teleport.Delay", _tp_delay);
+        _file.set("Teleport.CoolDown", _tp_cool_down);
+        _file.set("Teleport.TpaExpire", _tp_tpa_expire);
+        _file.set("Teleport.RtpRadius", _tp_rtp_radius);
+        _file.set("Teleport.WorldBlackList", _tp_world_blacklist);
+        _file.set("Chair.Enable", _chair_enable);
+        _file.set("Chair.MaxWidth", _chair_max_width);
+        _file.set("Chair.SignCheck", _chair_sign_check);
+        _file.set("Chair.SitHeight", _chair_sit_height);
+        _file.set("Recipes.CrowBar", _recipes_crowbar);
+        _file.set("Recipes.InvisibleItemFrame", _recipes_invisible_item_frame);
+        _file.set("Recipes.LightBlock", _recipes_light_block);
+        _file.set("Recipes.StackedEnchantBook", _recipes_stacked_enchant_book);
+        _file.set("HomeLimit.Amount", _home_limit_amount);
+        _file.set("HomeLimit.WorldBlacklist", _home_world_blacklist);
+        _file.set("Database.Type", _db_type);
+        _file.set("Database.Host", _db_host);
+        _file.set("Database.Port", _db_port);
+        _file.set("Database.Name", _db_name);
+        _file.set("Database.User", _db_user);
+        _file.set("Database.Pass", _db_pass);
+        _file.set("Prefix.Enable", _prefix_enable);
+        _file.set("Prefix.Format", _prefix_format);
+        _plugin.saveConfig();
     }
 
     public Boolean isDebug() {
@@ -274,6 +313,26 @@ public class ConfigManager {
         return _db_pass;
     }
 
+    public Boolean getPrefixEnable() {
+        return _prefix_enable;
+    }
+
+    public void setPrefixEnable(Boolean enable) {
+        _prefix_enable = enable;
+        _file.set("Prefix.Enable", enable);
+        _plugin.saveConfig();
+    }
+
+    public String getPrefixFormat() {
+        return _prefix_format;
+    }
+
+    public void setPrefixFormat(String format) {
+        _prefix_format = format;
+        _file.set("Prefix.Format", format);
+        _plugin.saveConfig();
+    }
+
 
     private final EssentialsD _plugin;
     private FileConfiguration _file;
@@ -311,4 +370,8 @@ public class ConfigManager {
     private String _db_user;
     private String _db_pass;
     private String _db_name;
+
+    // prefix
+    private Boolean _prefix_enable;
+    private String _prefix_format;
 }

src/main/resources/config.yml

@@ -55,6 +55,11 @@ HomeLimit:
   Amount: 5             # 数量限制
   WorldBlackList: [ ]   # 不允许设置 home 的世界
 
+# prefix (需要 PlaceholderAPI 支持)
+Prefix:
+  Enable: false
+  Format: '<%player_name%> '
+
 Debug: false
 
 CheckUpdate: true

src/main/resources/plugin.yml

@@ -8,6 +8,7 @@ load: STARTUP
 folia-supported: true
 softdepend:
   - LuckPerms
+  - PlaceholderAPI
 permissions:
   essd.*:
     default: op