Unregister placeholder extension when Plan disables

Affects issues:
- Fixed #2833

Plan/bukkit/src/main/java/com/djrapitops/plan/Plan.java

@@ -58,6 +58,7 @@ public class Plan extends JavaPlugin implements PlanPlugin {
     private RunnableFactory runnableFactory;
     private PlatformAbstractionLayer abstractionLayer;
     private ErrorLogger errorLogger;
+    private PlanBukkitComponent component;
 
     @Override
     public void onLoad() {
@@ -68,7 +69,7 @@ public class Plan extends JavaPlugin implements PlanPlugin {
 
     @Override
     public void onEnable() {
-        PlanBukkitComponent component = DaggerPlanBukkitComponent.builder()
+        component = DaggerPlanBukkitComponent.builder()
                 .plan(this)
                 .abstractionLayer(abstractionLayer)
                 .server(getServer())
@@ -135,11 +136,18 @@ public class Plan extends JavaPlugin implements PlanPlugin {
     public void onDisable() {
         storeSessionsOnShutdown();
         cancelAllTasks();
+        if (component != null) unregisterPlaceholders(component.placeholders());
         if (system != null) system.disable();
 
         pluginLogger.info(Locale.getStringNullSafe(locale, PluginLang.DISABLED));
     }
 
+    private void unregisterPlaceholders(BukkitPlaceholderRegistrar placeholders) {
+        if (placeholders != null) {
+            placeholders.unregister();
+        }
+    }
+
     private void storeSessionsOnShutdown() {
         if (serverShutdownSave != null) {
             Optional<Future<?>> complete = serverShutdownSave.performSave();

Plan/bukkit/src/main/java/com/djrapitops/plan/addons/placeholderapi/BukkitPlaceholderRegistrar.java

@@ -30,6 +30,8 @@ public class BukkitPlaceholderRegistrar {
     private final PlanSystem system;
     private final ErrorLogger errorLogger;
 
+    private PlanPlaceholderExtension placeholderExtension;
+
     @Inject
     public BukkitPlaceholderRegistrar(
             PlanPlaceholders placeholders,
@@ -42,6 +44,13 @@ public class BukkitPlaceholderRegistrar {
     }
 
     public void register() {
-        new PlanPlaceholderExtension(placeholders, system, errorLogger).register();
+        placeholderExtension = new PlanPlaceholderExtension(placeholders, system, errorLogger);
+        placeholderExtension.register();
+    }
+
+    public void unregister() {
+        if (placeholderExtension != null) {
+            placeholderExtension.unregister();
+        }
     }
 }

Plan/bukkit/src/main/java/com/djrapitops/plan/addons/placeholderapi/PlanPlaceholderExtension.java

@@ -91,11 +91,19 @@ public class PlanPlaceholderExtension extends PlaceholderExpansion {
 
     @Override
     public String onRequest(OfflinePlayer player, @Untrusted String params) {
-        UUID uuid = player != null ? player.getUniqueId() : null;
+        try {
-        if ("Server thread".equalsIgnoreCase(Thread.currentThread().getName())) {
+            UUID uuid = player != null ? player.getUniqueId() : null;
-            return getCached(params, uuid);
+            if ("Server thread".equalsIgnoreCase(Thread.currentThread().getName())) {
+                return getCached(params, uuid);
+            }
+            return getPlaceholderValue(params, uuid);
+        } catch (IllegalStateException e) {
+            if ("zip file closed".equals(e.getMessage())) {
+                return null; // Plan is disabled.
+            } else {
+                throw e;
+            }
         }
-        return getPlaceholderValue(params, uuid);
     }
 
     private String getPlaceholderValue(@Untrusted String params, UUID uuid) {