Adding Java docs for Serialization, and discovered some flaws with the Java API, that have been fixed

akka-docs/java/code/akka/docs/serialization/SerializationDocTest.scala

@@ -0,0 +1,8 @@
+/**
+ * Copyright (C) 2009-2011 Typesafe Inc. <http://www.typesafe.com>
+ */
+package akka.docs.serialization
+
+import org.scalatest.junit.JUnitSuite
+
+class SerializationDocTest extends SerializationDocTestBase with JUnitSuite

akka-docs/java/code/akka/docs/serialization/SerializationDocTestBase.java

@@ -0,0 +1,135 @@
+/**
+ * Copyright (C) 2009-2011 Typesafe Inc. <http://www.typesafe.com>
+ */
+package akka.docs.serialization;
+
+import akka.serialization.JSerializer;
+import akka.serialization.Serialization;
+import akka.serialization.SerializationExtension;
+import akka.serialization.Serializer;
+import org.junit.Test;
+//#imports
+
+import akka.serialization.*;
+import akka.actor.ActorSystem;
+import com.typesafe.config.*;
+
+//#imports
+
+public class SerializationDocTestBase {
+  //#my-own-serializer
+    public static class MyOwnSerializer extends JSerializer {
+
+      // This is whether "fromBinary" requires a "clazz" or not
+      @Override public boolean includeManifest() {
+          return false;
+      }
+
+      // Pick a unique identifier for your Serializer,
+      // you've got a couple of billions to choose from,
+      // 0 - 16 is reserved by Akka itself
+      @Override public int identifier() {
+          return 1234567;
+      }
+
+      // "toBinary" serializes the given object to an Array of Bytes
+      @Override public byte[] toBinary(Object obj) {
+        // Put the code that serializes the object here
+        //#...
+        return new byte[0];
+        //#...
+      }
+
+      // "fromBinary" deserializes the given array,
+      // using the type hint (if any, see "includeManifest" above)
+      // into the optionally provided classLoader.
+      @Override public Object fromBinary(byte[] bytes,
+                     Class clazz,
+                     ClassLoader classLoader) {
+        // Put your code that deserializes here
+        //#...
+        return null;
+        //#...
+      }
+    }
+//#my-own-serializer
+    @Test public void haveExamples() {
+        /*
+        //#serialize-messages-config
+        akka {
+          actor {
+            serialize-messages = on
+          }
+        }
+        //#serialize-messages-config
+
+        //#serialize-creators-config
+        akka {
+          actor {
+            serialize-creators = on
+          }
+        }
+        //#serialize-creators-config
+
+
+        //#serialize-serializers-config
+        akka {
+          actor {
+            serializers {
+              default = "akka.serialization.JavaSerializer"
+
+              myown = "akka.docs.serialization.MyOwnSerializer"
+            }
+          }
+        }
+        //#serialize-serializers-config
+
+        //#serialization-bindings-config
+        akka {
+          actor {
+            serializers {
+              default = "akka.serialization.JavaSerializer"
+              java = "akka.serialization.JavaSerializer"
+              myown = "akka.docs.serialization.MyOwnSerializer"
+            }
+
+            serialization-bindings {
+             java = ["java.lang.String",
+                     "app.my.Customer"]
+             myown = ["my.own.BusinessObject",
+                      "something.equally.Awesome",
+                      "java.lang.Boolean"]
+           }
+          }
+        }
+        //#serialization-bindings-config
+        */
+    }
+
+    @Test public void demonstrateTheProgrammaticAPI() {
+      //#programmatic
+      ActorSystem system = ActorSystem.create("example");
+
+      // Get the Serialization Extension
+      Serialization serialization = SerializationExtension.get(system);
+
+      // Have something to serialize
+      String original = "woohoo";
+
+      // Find the Serializer for it
+      Serializer serializer = serialization.findSerializerFor(original);
+
+      // Turn it into bytes
+      byte[] bytes = serializer.toBinary(original);
+
+      // Turn it back into an object,
+      // the nulls are for the class manifest and for the classloader
+      String back = (String)serializer.fromBinary(bytes);
+
+      // Voilá!
+      assertEquals(original, back);
+
+      //#programmatic
+      system.shutdown();
+    }
+}

akka-docs/java/serialization.rst

@@ -5,8 +5,90 @@
  Serialization (Java)
 #####################
 
-Serialization will soon be documented.
+.. sidebar:: Contents
 
-Until then we refer to the following section in the configuration file:
+   .. contents:: :local:
 
-* `Serializers <https://github.com/jboner/akka/blob/master/akka-actor/src/main/resources/reference.conf#L180>`_
+Akka has a built-in Extension for serialization,
+and it is both possible to use the built-in serializers and to write your own.
+
+The serialization mechanism is both used by Akka internally to serialize messages,
+and available for ad-hoc serialization of whatever you might need it for.
+
+Usage
+=====
+
+Configuration
+-------------
+
+For Akka to know which ``Serializer`` to use for what, you need edit your Akka Configuration,
+in the "akka.actor.serializers"-section you bind names to implementations of the ``akka.serialization.Serializer``
+you wish to use, like this:
+
+.. includecode:: code/akka/docs/serialization/SerializationDocTestBase.java#serialize-serializers-config
+
+.. note::
+
+   The name ``default`` is special in the sense that the ``Serializer``
+   mapped to it will be used as default.
+
+After you've bound names to different implementations of ``Serializer`` you need to wire which classes
+should be serialized using which ``Serializer``, this is done in the "akka.actor.serialization-bindings"-section:
+
+.. includecode:: code/akka/docs/serialization/SerializationDocTestBase.java#serialization-bindings-config
+
+.. note::
+
+   Akka currently only checks for absolute equality of Classes, i.e. it does not yet check ``isAssignableFrom``,
+   this means that you'll need to list the specific classes.
+
+Verification
+------------
+
+If you want to verify that your messages are serializable you can enable the following config option:
+
+.. includecode:: code/akka/docs/serialization/SerializationDocTestBase.java#serialize-messages-config
+
+.. warning::
+
+   We only recommend using the config option turned on when you're running tests.
+   It is completely pointless to have it turned on in other scenarios.
+
+If you want to verify that your ``Props`` are serializable you can enable the following config option:
+
+.. includecode:: code/akka/docs/serialization/SerializationDocTestBase.java#serialize-creators-config
+
+.. warning::
+
+   We only recommend using the config option turned on when you're running tests.
+   It is completely pointless to have it turned on in other scenarios.
+
+Programmatic
+------------
+
+If you want to programmatically serialize/deserialize using Akka Serialization,
+here's some examples:
+
+.. includecode:: code/akka/docs/serialization/SerializationDocTestBase.java
+   :include: imports,programmatic
+
+For more information, have a look at the ``ScalaDoc`` for ``akka.serialization._``
+
+Customization
+=============
+
+So, lets say that you want to create your own ``Serializer``,
+you saw the ``akka.docs.serialization.MyOwnSerializer`` in the config example above?
+
+Creating new Serializers
+------------------------
+
+First you need to create a class definition of your ``Serializer``,
+which is done by extending ``akka.serialization.JSerializer``, like this:
+
+.. includecode:: code/akka/docs/serialization/SerializationDocTestBase.java
+   :include: imports,my-own-serializer
+   :exclude: ...
+
+Then you only need to fill in the blanks, bind it to a name in your Akka Configuration and then
+list which classes that should be serialized using it.