Share the metadata map-copy helper between Players and Island

src/main/java/world/bentobox/bentobox/api/metadata/MetaDataAble.java

@@ -1,6 +1,7 @@
 package world.bentobox.bentobox.api.metadata;
 
 import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.Optional;
 
 /**
@@ -56,4 +57,24 @@ default Optional<MetaDataValue> removeMetaData(String key) {
         return getMetaData().map(m -> m.remove(key));
     }
 
+    /**
+     * Copies the given map into a new {@link ConcurrentHashMap}, dropping null keys and values,
+     * which a concurrent map cannot hold. Implementations use this to make their backing map
+     * safe for concurrent access without mutating the caller's map.
+     * @param source map to copy, may be null
+     * @return a mutable, thread-safe copy
+     * @since 3.23.0
+     */
+    static Map<String, MetaDataValue> toConcurrentMap(Map<String, MetaDataValue> source) {
+        Map<String, MetaDataValue> result = new ConcurrentHashMap<>();
+        if (source != null) {
+            source.forEach((key, value) -> {
+                if (key != null && value != null) {
+                    result.put(key, value);
+                }
+            });
+        }
+        return result;
+    }
+
 }

src/main/java/world/bentobox/bentobox/database/objects/Island.java

@@ -13,7 +13,6 @@
 import java.util.Optional;
 import java.util.Set;
 import java.util.UUID;
-import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.stream.Collectors;
@@ -293,7 +292,7 @@ public Island(Island island) {
         this.maxHomes = island.getMaxHomes();
         this.maxMembers = new HashMap<>(island.getMaxMembers());
         this.members.putAll(island.getMembers());
-        this.metaData = island.getMetaData().map(Island::toConcurrentMap).orElse(null);
+        this.metaData = island.getMetaData().map(MetaDataAble::toConcurrentMap).orElse(null);
         this.name = island.getName();
         this.owner = island.getOwner();
         this.protectionRange = island.getProtectionRange();
@@ -1756,36 +1755,18 @@ public void setReserved(boolean reserved) {
     @Override
     public Optional<Map<String, MetaDataValue>> getMetaData() {
         if (!(metaData instanceof ConcurrentMap)) {
-            metaData = toConcurrentMap(metaData);
+            metaData = MetaDataAble.toConcurrentMap(metaData);
         }
         return Optional.of(metaData);
     }
 
-    /**
-     * Copies the given map into a new {@link ConcurrentHashMap}, dropping null keys and values,
-     * which a concurrent map cannot hold.
-     * @param source map to copy, may be null
-     * @return a mutable, thread-safe copy
-     */
-    private static Map<String, MetaDataValue> toConcurrentMap(Map<String, MetaDataValue> source) {
-        Map<String, MetaDataValue> result = new ConcurrentHashMap<>();
-        if (source != null) {
-            source.forEach((key, value) -> {
-                if (key != null && value != null) {
-                    result.put(key, value);
-                }
-            });
-        }
-        return result;
-    }
-
     /**
      * @param metaData the metaData to set
      * @since 1.15.4
      */
     @Override
     public void setMetaData(Map<String, MetaDataValue> metaData) {
-        this.metaData = metaData == null ? null : toConcurrentMap(metaData);
+        this.metaData = metaData == null ? null : MetaDataAble.toConcurrentMap(metaData);
         setChanged();
     }
 

src/main/java/world/bentobox/bentobox/database/objects/Players.java

@@ -6,7 +6,6 @@
 import java.util.Optional;
 import java.util.Set;
 import java.util.UUID;
-import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 
 import org.bukkit.Bukkit;
@@ -254,7 +253,7 @@ public void addToPendingKick(World world)
      * <p>
      * The map may arrive as {@code null} (new player), as an immutable or Gson-created map
      * (deserialization), or as a plain {@link HashMap}. All of these are copied once into a
-     * {@link ConcurrentHashMap}. Metadata is read by many addons on hot paths such as
+     * {@link java.util.concurrent.ConcurrentHashMap}. Metadata is read by many addons on hot paths such as
      * {@code PlayerMoveEvent} and can be touched from other threads, so the backing map must
      * tolerate concurrent access without corrupting itself.
      * @return the metaData
@@ -264,29 +263,11 @@ public void addToPendingKick(World world)
     @Override
     public Optional<Map<String, MetaDataValue>> getMetaData() {
         if (!(metaData instanceof ConcurrentMap)) {
-            metaData = toConcurrentMap(metaData);
+            metaData = MetaDataAble.toConcurrentMap(metaData);
         }
         return Optional.of(metaData);
     }
 
-    /**
-     * Copies the given map into a new {@link ConcurrentHashMap}, dropping null keys and values,
-     * which a concurrent map cannot hold.
-     * @param source map to copy, may be null
-     * @return a mutable, thread-safe copy
-     */
-    private static Map<String, MetaDataValue> toConcurrentMap(Map<String, MetaDataValue> source) {
-        Map<String, MetaDataValue> result = new ConcurrentHashMap<>();
-        if (source != null) {
-            source.forEach((key, value) -> {
-                if (key != null && value != null) {
-                    result.put(key, value);
-                }
-            });
-        }
-        return result;
-    }
-
     /**
      * Sets the player's metadata. The map is copied into a thread-safe map, so the caller's map
      * is never mutated and immutable maps are accepted.
@@ -296,7 +277,7 @@ private static Map<String, MetaDataValue> toConcurrentMap(Map<String, MetaDataVa
      */
     @Override
     public void setMetaData(Map<String, MetaDataValue> metaData) {
-        this.metaData = metaData == null ? null : toConcurrentMap(metaData);
+        this.metaData = metaData == null ? null : MetaDataAble.toConcurrentMap(metaData);
     }
 
     /**