1 files changed, 46 insertions, 0 deletions
diff --git a/guava/src/com/google/common/cache/RemovalListener.java b/guava/src/com/google/common/cache/RemovalListener.java
new file mode 100644
index 0000000..e9b6c2c
--- /dev/null
+++ b/guava/src/com/google/common/cache/RemovalListener.java
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2011 The Guava Authors
+ *
+ * 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 com.google.common.cache;
+
+import com.google.common.annotations.Beta;
+
+/**
+ * An object that can receive a notification when an entry is removed from a cache. The removal
+ * resulting in notification could have occured to an entry being manually removed or replaced, or
+ * due to eviction resulting from timed expiration, exceeding a maximum size, or garbage
+ * collection.
+ *
+ * <p>An instance may be called concurrently by multiple threads to process different entries.
+ * Implementations of this interface should avoid performing blocking calls or synchronizing on
+ * shared resources.
+ *
+ * @param <K> the most general type of keys this listener can listen for; for
+ *     example {@code Object} if any key is acceptable
+ * @param <V> the most general type of values this listener can listen for; for
+ *     example {@code Object} if any key is acceptable
+ * @author Charles Fry
+ * @since 10.0
+ */
+@Beta
+public interface RemovalListener<K, V> {
+  /**
+   * Notifies the listener that a removal occurred at some point in the past.
+   */
+  // Technically should accept RemovalNotification<? extends K, ? extends V>, but because
+  // RemovalNotification is guaranteed covariant, let's make users' lives simpler.
+  void onRemoval(RemovalNotification<K, V> notification);
+}