add paper 1.20.6+ supports

src/main/java/pers/xanadu/enderdragon/manager/GroovyManager.java

@@ -61,8 +61,10 @@ public class GroovyManager {
     public static Object eval(String expression, Player player){
         Binding binding = new Binding();
         binding.setVariable("player",player);
+        if (player != null){
             binding.setVariable("itemStack",player.getItemInHand());
             binding.setVariable("world",player.getWorld());
+        }
         GroovyShell shell = new GroovyShell(GroovyManager.class.getClassLoader(),binding,compilerConfig);
         return shell.evaluate(lib+expression);
     }

src/main/java/pers/xanadu/enderdragon/util/Version.java

@@ -1,12 +1,16 @@
 package pers.xanadu.enderdragon.util;
 
 import lombok.Getter;
+import org.bukkit.Bukkit;
+import pers.xanadu.enderdragon.EnderDragon;
 import pers.xanadu.enderdragon.config.Lang;
 import pers.xanadu.enderdragon.nms.BossBar.IBossBarManager;
 import pers.xanadu.enderdragon.nms.NMSItem.INMSItemManager;
 import pers.xanadu.enderdragon.nms.RespawnAnchor.IRespawnAnchorManager;
 import pers.xanadu.enderdragon.nms.WorldData.IWorldDataManager;
 
+import java.lang.reflect.Field;
+
 import static org.bukkit.Bukkit.getServer;
 
 public class Version {
@@ -24,14 +28,22 @@ public class Version {
     public static void init(){
         try {
             version = getServer().getClass().getPackage().getName().split("\\.")[3];
+        } catch (Throwable throwable) {
+            try{
+                //paper 1.20.6+
+                Class<?> clazz = Class.forName("io.papermc.paper.util.MappingEnvironment");
+                Field LEGACY_CB_VERSION = clazz.getField("LEGACY_CB_VERSION");
+                version = (String) LEGACY_CB_VERSION.get(null);
+            }catch (ReflectiveOperationException e){
+                throwable.printStackTrace();
+                Lang.warn("Failed to get nms-version!");
+                Bukkit.getServer().getPluginManager().disablePlugin(EnderDragon.plugin);
+            }
+        }
         String[] mc_version = getServer().getBukkitVersion().split("-")[0].split("\\.");
         mcMainVersion = Integer.parseInt(mc_version[1]);
         if(mc_version.length<=2) mcPatchVersion = 0;
         else mcPatchVersion = Integer.parseInt(mc_version[2]);
-        } catch (Throwable throwable) {
-            throwable.printStackTrace();
-            Lang.warn("Failed to get nms-version!");
-        }
         Lang.info("Found version: " + version);
         try{
             Class.forName("net.minecraftforge.server.ServerMain");

src/main/resources/plugin.yml

@@ -1,5 +1,5 @@
 name: EnderDragon
-version: 2.5.2
+version: 2.5.3
 main: pers.xanadu.enderdragon.EnderDragon
 author: Xanadu13
 api-version: 1.13