Bug 5740: Change TimeoutNow and Shutdown to externalizable proxy

Change-Id: I3b2289c258ffab288901b5cbf4e5032bc143dfc7
Signed-off-by: Tom Pantelis <tompantelis@gmail.com>

diff --git a/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/base/messages/EmptyExternalizableProxy.java b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/base/messages/EmptyExternalizableProxy.java
new file mode 100644 (file)
index 0000000..4f1fe37
--- /dev/null
+++ b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/base/messages/EmptyExternalizableProxy.java
@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2017 Inocybe Technologies and others.  All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
+package org.opendaylight.controller.cluster.raft.base.messages;
+
+import com.google.common.base.Preconditions;
+import java.io.Externalizable;
+import java.io.IOException;
+import java.io.ObjectInput;
+import java.io.ObjectOutput;
+
+/**
+ * Abstract base that implements Externalizable with no-op methods that is intended for classes that use the
+ * externalizable proxy pattern but have no data to serialize and read-resolve to a static instance.
+ *
+ * @author Thomas Pantelis
+ */
+public abstract class EmptyExternalizableProxy implements Externalizable {
+    private static final long serialVersionUID = 1L;
+
+    private final Object readResolveTo;
+
+    protected EmptyExternalizableProxy(Object readResolveTo) {
+        this.readResolveTo = Preconditions.checkNotNull(readResolveTo);
+    }
+
+    @Override
+    public void writeExternal(ObjectOutput out) throws IOException {
+    }
+
+    @Override
+    public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
+    }
+
+    protected Object readResolve() {
+        return readResolveTo;
+    }
+}

diff --git a/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/base/messages/TimeoutNow.java b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/base/messages/TimeoutNow.java
index 5a753c24c99efe224b752299cfcdfc25168915f7..b85d8b7008393e0eac64c0c70bb6fa8a7ab95820 100644 (file)
--- a/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/base/messages/TimeoutNow.java
+++ b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/base/messages/TimeoutNow.java
@@ -22,7 +22,18 @@ public final class TimeoutNow implements Serializable {
         // Hidden on purpose
     }
 
-    private Object readResolve() {
-        return INSTANCE;
+    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);
+        }
     }
 }

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 4261baef2fd22f19c5374139f34f15ba063eb1b5..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
@@ -8,6 +8,7 @@
 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
@@ -24,7 +25,18 @@ public final class Shutdown implements Serializable {
         // Hidden on purpose
     }
 
-    private Object readResolve() {
-        return INSTANCE;
+    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);
+        }
     }
 }

diff --git a/opendaylight/md-sal/sal-akka-raft/src/test/java/org/opendaylight/controller/cluster/raft/base/messages/TimeoutNowTest.java b/opendaylight/md-sal/sal-akka-raft/src/test/java/org/opendaylight/controller/cluster/raft/base/messages/TimeoutNowTest.java
new file mode 100644 (file)
index 0000000..26cdb22
--- /dev/null
+++ b/opendaylight/md-sal/sal-akka-raft/src/test/java/org/opendaylight/controller/cluster/raft/base/messages/TimeoutNowTest.java
@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2017 Inocybe Technologies and others.  All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
+package org.opendaylight.controller.cluster.raft.base.messages;
+
+import static org.junit.Assert.assertSame;
+
+import org.apache.commons.lang.SerializationUtils;
+import org.junit.Test;
+
+/**
+ * Unit tests for TimeoutNow.
+ *
+ * @author Thomas Pantelis
+ */
+public class TimeoutNowTest {
+
+    @Test
+    public void test() {
+        TimeoutNow cloned = (TimeoutNow) SerializationUtils.clone(TimeoutNow.INSTANCE);
+        assertSame("Cloned instance", TimeoutNow.INSTANCE, cloned);
+    }
+}

diff --git a/opendaylight/md-sal/sal-akka-raft/src/test/java/org/opendaylight/controller/cluster/raft/client/messages/ShutdownTest.java b/opendaylight/md-sal/sal-akka-raft/src/test/java/org/opendaylight/controller/cluster/raft/client/messages/ShutdownTest.java
new file mode 100644 (file)
index 0000000..81b9fbb
--- /dev/null
+++ b/opendaylight/md-sal/sal-akka-raft/src/test/java/org/opendaylight/controller/cluster/raft/client/messages/ShutdownTest.java
@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2017 Inocybe Technologies and others.  All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
+package org.opendaylight.controller.cluster.raft.client.messages;
+
+import static org.junit.Assert.assertSame;
+
+import org.apache.commons.lang.SerializationUtils;
+import org.junit.Test;
+
+/**
+ * Unit tests for Shutdown.
+ *
+ * @author Thomas Pantelis
+ */
+public class ShutdownTest {
+
+    @Test
+    public void test() {
+        Shutdown cloned = (Shutdown) SerializationUtils.clone(Shutdown.INSTANCE);
+        assertSame("Cloned instance", Shutdown.INSTANCE, cloned);
+    }
+}