Add a close() method to Cache

core/src/main/scala/scalacache/Cache.scala

@@ -29,5 +29,15 @@ trait Cache {
    */
   def remove(key: String): Future[Unit]
 
+  /**
+   * You should call this when you have finished using this Cache.
+   * (e.g. when your application shuts down)
+   *
+   * It will take care of gracefully shutting down the underlying cache client.
+   *
+   * Note that you should not try to use this Cache instance after you have called this method.
+   */
+  def close(): Unit
+
 }
 

core/src/test/scala/scalacache/mocks.scala

@@ -8,18 +8,21 @@ class EmptyCache extends Cache {
   override def get[V](key: String): Future[Option[V]] = Future.successful(None)
   override def put[V](key: String, value: V, ttl: Option[Duration]) = Future.successful((): Unit)
   override def remove(key: String) = Future.successful((): Unit)
+  override def close(): Unit = {}
 }
 
 class FullCache(value: Any) extends Cache {
   override def get[V](key: String): Future[Option[V]] = Future.successful(Some(value).asInstanceOf[Option[V]])
   override def put[V](key: String, value: V, ttl: Option[Duration]) = Future.successful((): Unit)
   override def remove(key: String) = Future.successful((): Unit)
+  override def close(): Unit = {}
 }
 
 class FailedFutureReturningCache extends Cache {
   override def get[V](key: String): Future[Option[V]] = Future.failed(new RuntimeException("failed to read"))
   override def put[V](key: String, value: V, ttl: Option[Duration]): Future[Unit] = Future.failed(new RuntimeException("failed to write"))
   override def remove(key: String) = Future.successful((): Unit)
+  override def close(): Unit = {}
 }
 
 /**
@@ -40,6 +43,9 @@ class MockCache extends Cache {
 
   def remove(key: String) =
     Future.successful(mmap.remove(key))
+
+  def close(): Unit = {}
+
 }
 
 /**

ehcache/src/main/scala/scalacache/ehcache/EhcacheCache.scala

@@ -53,6 +53,10 @@ class EhcacheCache(underlying: Ehcache)
    */
   override def remove(key: String) = Future.successful(underlying.remove(key))
 
+  override def close(): Unit = {
+    // Nothing to do
+  }
+
 }
 
 object EhcacheCache {

guava/src/main/scala/scalacache/guava/GuavaCache.scala

@@ -62,6 +62,10 @@ class GuavaCache(underlying: GCache[String, Object])
    */
   override def remove(key: String) = Future.successful(underlying.invalidate(key))
 
+  override def close(): Unit = {
+    // Nothing to do
+  }
+
   private def toExpiryTime(ttl: Duration): DateTime = DateTime.now.plusMillis(ttl.toMillis.toInt)
 
 }

lrumap/src/main/scala/scalacache/lrumap/LruMapCache.scala

@@ -62,6 +62,10 @@ class LruMapCache(underlying: LruMap[String, Object])
   override def remove(key: String): Future[Unit] =
     Future.successful(underlying.remove(key))
 
+  override def close(): Unit = {
+    // Nothing to do
+  }
+
   private def toExpiryTime(ttl: Duration): DateTime = DateTime.now.plusMillis(ttl.toMillis.toInt)
 }
 

memcached/src/main/scala/scalacache/memcached/MemcachedCache.scala

@@ -71,6 +71,10 @@ class MemcachedCache(client: MemcachedClient, keySanitizer: MemcachedKeySanitize
     p.future
   }
 
+  override def close(): Unit = {
+    client.shutdown()
+  }
+
 }
 
 object MemcachedCache {

redis/src/main/scala/scalacache/redis/RedisCache.scala

@@ -75,6 +75,10 @@ class RedisCache(jedisPool: JedisPool, override val customClassloader: Option[Cl
     }
   }
 
+  override def close(): Unit = {
+    jedisPool.close()
+  }
+
   private def withJedisClient[T](f: Jedis => T): T = {
     val jedis = jedisPool.getResource()
     try {