Bug 5740: Change TimeoutNow and Shutdown to externalizable proxy

[controller.git] / opendaylight / md-sal / sal-akka-raft / src / main / java / org / opendaylight / controller / cluster / raft / client / messages / Shutdown.java

diff --git a/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/client/messages/Shutdown.java b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/client/messages/Shutdown.java
index 930a4b0471f5152b4abe3f08b45b81198c67f675..22acc41e01e9dfee46042a008c813ff1f1cc561d 100644 (file)
--- a/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/client/messages/Shutdown.java
+++ b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/client/messages/Shutdown.java
@@ -8,13 +8,35 @@
 package org.opendaylight.controller.cluster.raft.client.messages;
 
 import java.io.Serializable;
+import org.opendaylight.controller.cluster.raft.base.messages.EmptyExternalizableProxy;
 
 /**
  * Message sent to a raft actor to shutdown gracefully. If it's the leader it will transfer leadership to a
- * follower. As its last act, the actor self-destructs via a PoisonPill.
+ * follower. As its last act, the actor self-destructs via a PoisonPill. This message should only be used with
+ * Patterns.gracefulStop().
  *
  * @author Thomas Pantelis
  */
-public class Shutdown implements Serializable {
+public final class Shutdown implements Serializable {
     private static final long serialVersionUID = 1L;
+    public static final Shutdown INSTANCE = new Shutdown();
+
+    private Shutdown() {
+        // Hidden on purpose
+    }
+
+    private Object writeReplace() {
+        return new Proxy();
+    }
+
+    private static class Proxy extends EmptyExternalizableProxy {
+        private static final long serialVersionUID = 1L;
+
+        // checkstyle flags the public modifier as redundant which really doesn't make sense since it clearly isn't
+        // redundant. It is explicitly needed for Java serialization to be able to create instances via reflection.
+        @SuppressWarnings("checkstyle:RedundantModifier")
+        public Proxy() {
+            super(INSTANCE);
+        }
+    }
 }