Akka/Scala example source code file (SerializationDocTest.java)

This example Akka source code file (SerializationDocTest.java) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Akka and Scala source code examples by using tags.

All credit for the original source code belongs to akka.io; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Akka tags/keywords

actor, actorsystem, address, akka, defaultaddress, defaultaddressext, extendedactorsystem, externaladdress, externaladdressext, id, override, serialize, string, test, testing, testkit

The SerializationDocTest.java Akka example source code

/**
 * Copyright (C) 2009-2014 Typesafe Inc. <http://www.typesafe.com>
 */
package docs.serialization;

import akka.testkit.JavaTestKit;
import org.junit.Test;
import static org.junit.Assert.*;
//#imports
import akka.actor.*;
import akka.serialization.*;

//#imports

public class SerializationDocTest {
  static
  //#my-own-serializer
  public 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)
    @Override public Object fromBinaryJava(byte[] bytes,
                                           Class<?> clazz) {
      // Put your code that deserializes here
      //#...
      return null;
      //#...
    }
  }
//#my-own-serializer

  @Test public void serializeActorRefs() {
    final ExtendedActorSystem extendedSystem = (ExtendedActorSystem)
      ActorSystem.create("whatever");
    final ActorRef theActorRef =
      extendedSystem.deadLetters(); // Of course this should be you

    //#actorref-serializer
    // Serialize
    // (beneath toBinary)
    String identifier = Serialization.serializedActorPath(theActorRef);

    // Then just serialize the identifier however you like

    // Deserialize
    // (beneath fromBinary)
    final ActorRef deserializedActorRef = extendedSystem.provider().resolveActorRef(
      identifier);
    // Then just use the ActorRef
    //#actorref-serializer
    JavaTestKit.shutdownActorSystem(extendedSystem);
  }

  static
  //#external-address
  public class ExternalAddressExt implements Extension {
    private final ExtendedActorSystem system;

    public ExternalAddressExt(ExtendedActorSystem system) {
      this.system = system;
    }

    public Address getAddressFor(Address remoteAddress) {
      final scala.Option<Address> optAddr = system.provider()
        .getExternalAddressFor(remoteAddress);
      if (optAddr.isDefined()) {
        return optAddr.get();
      } else {
        throw new UnsupportedOperationException(
          "cannot send to remote address " + remoteAddress);
      }
    }
  }

  //#external-address
  static
  //#external-address
  public class ExternalAddress extends
    AbstractExtensionId<ExternalAddressExt> implements ExtensionIdProvider {
    public static final ExternalAddress ID = new ExternalAddress();

    public ExternalAddress lookup() {
      return ID;
    }

    public ExternalAddressExt createExtension(ExtendedActorSystem system) {
      return new ExternalAddressExt(system);
    }
  }

  //#external-address
  static
  //#external-address
  public class ExternalAddressExample {
    //#external-address
    final ActorSystem system = ActorSystem.create();
    //#external-address
    public String serializeTo(ActorRef ref, Address remote) {
      return ref.path().toSerializationFormatWithAddress(
          ExternalAddress.ID.get(system).getAddressFor(remote));
    }
  }

  //#external-address

  static
  //#external-address-default
  public class DefaultAddressExt implements Extension {
    private final ExtendedActorSystem system;

    public DefaultAddressExt(ExtendedActorSystem system) {
      this.system = system;
    }

    public Address getAddress() {
      return system.provider().getDefaultAddress();
    }
  }

  //#external-address-default
  static
  //#external-address-default
  public class DefaultAddress extends
      AbstractExtensionId<DefaultAddressExt> implements ExtensionIdProvider {
    public static final DefaultAddress ID = new DefaultAddress();

    public DefaultAddress lookup() {
      return ID;
    }

    public DefaultAddressExt createExtension(ExtendedActorSystem system) {
      return new DefaultAddressExt(system);
    }
  }

  //#external-address-default

  public void demonstrateDefaultAddress() {
    // this is not meant to be run, only to be compiled
    final ActorSystem system = ActorSystem.create();
    final Address remoteAddr = new Address("", "");
    // #external-address-default
    final Address addr = DefaultAddress.ID.get(system).getAddress();
    // #external-address-default
  }

  @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
    JavaTestKit.shutdownActorSystem(system);
  }
}