Fixes a bug where newly created dropper arenas had a null reference to the handler

src/main/java/net/knarcraft/dropper/arena/DropperArena.java

@@ -1,6 +1,5 @@
 package net.knarcraft.dropper.arena;
 
-import net.knarcraft.dropper.Dropper;
 import net.knarcraft.dropper.property.ArenaGameMode;
 import net.knarcraft.dropper.util.StringSanitizer;
 import org.bukkit.Location;
@@ -61,7 +60,7 @@ public class DropperArena {
      */
     private final DropperArenaData dropperArenaData;
 
-    private static DropperArenaHandler dropperArenaHandler = null;
+    private final DropperArenaHandler dropperArenaHandler;
 
     /**
      * Instantiates a new dropper arena
@@ -74,10 +73,12 @@ public class DropperArena {
      * @param playerHorizontalVelocity <p>The velocity to use for players' horizontal velocity (-1 to 1)</p>
      * @param winBlockType             <p>The material of the block players have to hit to win this dropper arena</p>
      * @param dropperArenaData         <p>The arena data keeping track of which players have done what in this arena</p>
+     * @param arenaHandler             <p>The arena handler used for saving any changes</p>
      */
     public DropperArena(@NotNull UUID arenaId, @NotNull String arenaName, @NotNull Location spawnLocation,
                         @Nullable Location exitLocation, double playerVerticalVelocity, float playerHorizontalVelocity,
-                        @NotNull Material winBlockType, @NotNull DropperArenaData dropperArenaData) {
+                        @NotNull Material winBlockType, @NotNull DropperArenaData dropperArenaData,
+                        @NotNull DropperArenaHandler arenaHandler) {
         this.arenaId = arenaId;
         this.arenaName = arenaName;
         this.spawnLocation = spawnLocation;
@@ -86,10 +87,7 @@ public class DropperArena {
         this.playerHorizontalVelocity = playerHorizontalVelocity;
         this.winBlockType = winBlockType;
         this.dropperArenaData = dropperArenaData;
-
+        this.dropperArenaHandler = arenaHandler;
-        if (dropperArenaHandler == null) {
-            dropperArenaHandler = Dropper.getInstance().getArenaHandler();
-        }
     }
 
     /**
@@ -100,8 +98,10 @@ public class DropperArena {
      *
      * @param arenaName     <p>The name of the arena</p>
      * @param spawnLocation <p>The location players spawn in when entering the arena</p>
+     * @param arenaHandler  <p>The arena handler used for saving any changes</p>
      */
-    public DropperArena(@NotNull String arenaName, @NotNull Location spawnLocation) {
+    public DropperArena(@NotNull String arenaName, @NotNull Location spawnLocation,
+                        @NotNull DropperArenaHandler arenaHandler) {
         this.arenaId = UUID.randomUUID();
         this.arenaName = arenaName;
         this.spawnLocation = spawnLocation;
@@ -116,6 +116,7 @@ public class DropperArena {
 
         this.dropperArenaData = new DropperArenaData(this.arenaId, recordRegistries, new HashMap<>());
         this.winBlockType = Material.WATER;
+        this.dropperArenaHandler = arenaHandler;
     }
 
     /**

src/main/java/net/knarcraft/dropper/command/CreateArenaCommand.java

@@ -2,6 +2,7 @@ package net.knarcraft.dropper.command;
 
 import net.knarcraft.dropper.Dropper;
 import net.knarcraft.dropper.arena.DropperArena;
+import net.knarcraft.dropper.arena.DropperArenaHandler;
 import net.knarcraft.dropper.util.StringSanitizer;
 import org.bukkit.command.Command;
 import org.bukkit.command.CommandExecutor;
@@ -35,14 +36,16 @@ public class CreateArenaCommand implements CommandExecutor {
             return false;
         }
 
-        DropperArena existingArena = Dropper.getInstance().getArenaHandler().getArena(arenaName);
+        DropperArenaHandler arenaHandler = Dropper.getInstance().getArenaHandler();
+
+        DropperArena existingArena = arenaHandler.getArena(arenaName);
         if (existingArena != null) {
             commandSender.sendMessage("There already exists a dropper arena with that name!");
             return false;
         }
 
-        DropperArena arena = new DropperArena(arenaName, player.getLocation());
+        DropperArena arena = new DropperArena(arenaName, player.getLocation(), arenaHandler);
-        Dropper.getInstance().getArenaHandler().addArena(arena);
+        arenaHandler.addArena(arena);
         commandSender.sendMessage("The arena was successfully created!");
         return true;
     }

src/main/java/net/knarcraft/dropper/util/ArenaStorageHelper.java

@@ -24,6 +24,7 @@ import java.util.Map;
 import java.util.Set;
 import java.util.UUID;
 import java.util.logging.Level;
+import java.util.logging.Logger;
 
 /**
  * A helper class for saving and loading arenas
@@ -152,9 +153,10 @@ public final class ArenaStorageHelper {
                 ArenaStorageKey.PLAYER_HORIZONTAL_VELOCITY.getKey()));
         SerializableMaterial winBlockType = (SerializableMaterial) configurationSection.get(
                 ArenaStorageKey.WIN_BLOCK_TYPE.getKey());
+        Logger logger = Dropper.getInstance().getLogger();
 
         if (arenaName == null || spawnLocation == null) {
-            Dropper.getInstance().getLogger().log(Level.SEVERE, "Could not load the arena at configuration " +
+            logger.log(Level.SEVERE, "Could not load the arena at configuration " +
                     "section " + configurationSection.getName() + ". Please check the arenas storage file for issues.");
             return null;
         }
@@ -164,7 +166,7 @@ public final class ArenaStorageHelper {
 
         DropperArenaData arenaData = loadArenaData(arenaId);
         if (arenaData == null) {
-            Dropper.getInstance().getLogger().log(Level.SEVERE, "Unable to load arena data for " + arenaId);
+            logger.log(Level.SEVERE, "Unable to load arena data for " + arenaId);
 
             Map<ArenaGameMode, DropperArenaRecordsRegistry> recordRegistries = new HashMap<>();
             for (ArenaGameMode arenaGameMode : ArenaGameMode.values()) {
@@ -174,7 +176,7 @@ public final class ArenaStorageHelper {
         }
 
         return new DropperArena(arenaId, arenaName, spawnLocation, exitLocation, verticalVelocity, horizontalVelocity,
-                winBlockType.material(), arenaData);
+                winBlockType.material(), arenaData, Dropper.getInstance().getArenaHandler());
     }
 
     /**