1 files changed, 44 insertions, 0 deletions
diff --git a/src/main/java/org/traccar/session/cache/WeakValueMap.java b/src/main/java/org/traccar/session/cache/WeakValueMap.java
new file mode 100644
index 000000000..8323e2c30
--- /dev/null
+++ b/src/main/java/org/traccar/session/cache/WeakValueMap.java
@@ -0,0 +1,44 @@
+/*
+ * Copyright 2023 Anton Tananaev (anton@traccar.org)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.traccar.session.cache;
+
+import java.lang.ref.WeakReference;
+import java.util.HashMap;
+import java.util.Map;
+
+public class WeakValueMap<K, V> {
+
+    private final Map<K, WeakReference<V>> map = new HashMap<>();
+
+    public void put(K key, V value) {
+        map.put(key, new WeakReference<>(value));
+    }
+
+    public V get(K key) {
+        WeakReference<V> weakReference = map.get(key);
+        return (weakReference != null) ? weakReference.get() : null;
+    }
+
+    public V remove(K key) {
+        WeakReference<V> weakReference = map.remove(key);
+        return (weakReference != null) ? weakReference.get() : null;
+    }
+
+    private void clean() {
+        map.entrySet().removeIf(entry -> entry.getValue().get() == null);
+    }
+
+}