WIP

src/main/java/world/bentobox/bentobox/BentoBox.java

@@ -324,6 +324,8 @@ public class BentoBox extends JavaPlugin implements Listener {
         // Stop all async database tasks
         shutdown = true;
 
+        HeadGetter.shutdown();
+
         if (addonsManager != null) {
             addonsManager.disableAddons();
         }

src/main/java/world/bentobox/bentobox/util/heads/ExpiringMap.java

@@ -0,0 +1,74 @@
+package world.bentobox.bentobox.util.heads;
+
+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 java.util.function.Function;
+
+public class ExpiringMap<K, V> {
+    private final Map<K, V> map;
+    private final ScheduledExecutorService scheduler;
+    private final long expirationTime;
+
+    public ExpiringMap(long expirationTime, TimeUnit timeUnit) {
+        this.map = new ConcurrentHashMap<>();
+        this.scheduler = Executors.newSingleThreadScheduledExecutor();
+        this.expirationTime = timeUnit.toMillis(expirationTime);
+    }
+
+    public void put(K key, V value) {
+        map.put(key, value);
+        scheduleRemoval(key);
+    }
+
+    public boolean containsKey(K key) {
+        return map.containsKey(key);
+    }
+
+    public V get(K key) {
+        return map.get(key);
+    }
+
+    public V remove(K key) {
+        return map.remove(key);
+    }
+
+    public int size() {
+        return map.size();
+    }
+
+    public V computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) {
+        return map.computeIfAbsent(key, k -> {
+            V value = mappingFunction.apply(k);
+            scheduleRemoval(k);
+            return value;
+        });
+    }
+
+    private void scheduleRemoval(final K key) {
+        scheduler.schedule(() -> map.remove(key), expirationTime, TimeUnit.MILLISECONDS);
+    }
+
+    public void shutdown() {
+        scheduler.shutdown();
+    }
+    /*
+    public static void main(String[] args) throws InterruptedException {
+        ExpiringMap<String, String> expiringMap = new ExpiringMap<>(5, TimeUnit.SECONDS);
+    
+        expiringMap.put("key1", "value1");
+        System.out.println("Initial size: " + expiringMap.size()); // Should print 1
+    
+        // Using computeIfAbsent
+        String value = expiringMap.computeIfAbsent("key2", k -> "computedValue");
+        System.out.println("Computed value for key2: " + value); // Should print "computedValue"
+        System.out.println("Size after computeIfAbsent: " + expiringMap.size()); // Should print 2
+    
+        Thread.sleep(6000);
+        System.out.println("Size after 6 seconds: " + expiringMap.size()); // Should print 0
+    
+        expiringMap.shutdown();
+    }*/
+}

src/main/java/world/bentobox/bentobox/util/heads/HeadGetter.java

@@ -5,13 +5,12 @@ import java.io.InputStreamReader;
 import java.net.HttpURLConnection;
 import java.net.URL;
 import java.util.Base64;
-import java.util.HashMap;
 import java.util.HashSet;
-import java.util.Map;
 import java.util.Queue;
 import java.util.Set;
 import java.util.UUID;
 import java.util.concurrent.LinkedBlockingQueue;
+import java.util.concurrent.TimeUnit;
 import java.util.stream.Collectors;
 
 import org.bukkit.Bukkit;
@@ -36,7 +35,7 @@ public class HeadGetter {
     /**
      * Local cache for storing player heads.
      */
-    private static final Map<String, HeadCache> cachedHeads = new HashMap<>();
+    private static final ExpiringMap<String, HeadCache> cachedHeads = new ExpiringMap<>(1, TimeUnit.HOURS);
 
     /**
      * Local cache for storing requested names and items which must be updated.
@@ -46,7 +45,8 @@ public class HeadGetter {
     /**
      * Requesters of player heads.
      */
-    private static final Map<String, Set<HeadRequester>> headRequesters = new HashMap<>();
+    private static final ExpiringMap<String, Set<HeadRequester>> headRequesters = new ExpiringMap<>(10,
+            TimeUnit.SECONDS);
 
     private static final String TEXTURES = "textures";
 
@@ -65,6 +65,14 @@ public class HeadGetter {
         this.runPlayerHeadGetter();
     }
 
+    /**
+     * Shutdown the schedulers
+     */
+    public static void shutdown() {
+        cachedHeads.shutdown();
+        headRequesters.shutdown();
+    }
+
     /**
      * @param panelItem - head to update
      * @param requester - callback class