Fix Folia compatibility by migrating to native Java Executors for async tasks

src/main/java/dev/bailey/etplaceholders/DataManager.java

@@ -7,8 +7,10 @@ import com.google.gson.JsonObject;
 import java.io.InputStreamReader;
 import java.net.HttpURLConnection;
 import java.net.URL;
-import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
 import org.bukkit.Bukkit;
 
 public class DataManager {
@@ -26,15 +28,23 @@ public class DataManager {
 
     private final String[] trackedModes = {"overall", "vanilla", "mace", "axe", "sword", "smp", "diamondsmp", "uhc", "pot", "nethop", "cart"};
     
+    private ScheduledExecutorService executor;
+
     public DataManager(ETPlaceholdersPlugin plugin) {
         this.plugin = plugin;
     }
 
     public void startTasks() {
         int minutes = plugin.getConfig().getInt("cache-refresh-minutes", 15);
-        long ticks = minutes * 60 * 20L;
         
-        Bukkit.getScheduler().runTaskTimerAsynchronously(plugin, this::refreshLeaderboards, 0L, ticks);
+        executor = Executors.newScheduledThreadPool(2);
+        executor.scheduleAtFixedRate(this::refreshLeaderboards, 0, minutes, TimeUnit.MINUTES);
+    }
+
+    public void stopTasks() {
+        if (executor != null && !executor.isShutdown()) {
+            executor.shutdownNow();
+        }
     }
 
     private String getApiUrl() {
@@ -112,7 +122,8 @@ public class DataManager {
     }
 
     public void fetchPlayerAsync(String playerName) {
-        Bukkit.getScheduler().runTaskAsynchronously(plugin, () -> {
+        if (executor != null && !executor.isShutdown()) {
+            executor.submit(() -> {
                 try {
                     HttpURLConnection conn = createConnection("/players/" + playerName);
                     if (conn.getResponseCode() == 200) {
@@ -142,6 +153,7 @@ public class DataManager {
                 }
             });
         }
+    }
 
     public String getPlayerTier(String playerName, String mode) {
         String pLow = playerName.toLowerCase();

src/main/java/dev/bailey/etplaceholders/ETPlaceholdersPlugin.java

@@ -24,7 +24,9 @@ public class ETPlaceholdersPlugin extends JavaPlugin {
 
     @Override
     public void onDisable() {
-        Bukkit.getScheduler().cancelTasks(this);
+        if (dataManager != null) {
+            dataManager.stopTasks();
+        }
     }
 
     public DataManager getDataManager() {

target/maven-archiver/pom.properties

@@ -1,3 +0,0 @@
-artifactId=ETPlaceholders
-groupId=dev.bailey
-version=1.0.0

target/maven-status/maven-compiler-plugin/compile/default-compile/createdFiles.lst

@@ -1,3 +0,0 @@
-dev\bailey\etplaceholders\DataManager.class
-dev\bailey\etplaceholders\ETExpansion.class
-dev\bailey\etplaceholders\ETPlaceholdersPlugin.class