jasongoodwin / learning-akka

Code From Learning Akka

learning-akka

Code From "Learning Akka", Jason Goodwin. The book is to be published by Packt Publishing Dec 2015

Organization

Each chapter's example is separated into a different folder. Navigate to the folder and read the README.md file. The README.md file will explain the contents of each folder, any preparation needed to run the tests, how to run the tests, and will document expected output.

Any questions please feel free to either raise a github ticket or mailme at

jay.michael.goodwin 
@ 
gmail.com

Notes at time of publishing

NOTE: There is a bug in the scala-java8-compat lib that is fixed in 0.6.0. The book was published citing 0.6.0 but I think 0.6.0 as published in Maven Central has an issue with one of its dependencies that causes it to fail on import however 0.7.0 is fine to use. If anything, check maven central and use the latest.

"org.scala-lang.modules" %% "scala-java8-compat" % "0.7.0"

Up to date code

If there are any errors etc, I'll fix them on github. The link to the code on github is: https://github.com/jasongoodwin/learning-akka/

learning-akka's Issues

What's the difference between "ask demo" and "tell demo" in AskAndTellDemoSpec of ch3

Chapter 2: Status.Failure usage

Hi,
In the chapter 2, AkkademyDb class, we have two different syntaxes for the same pattern (sending a failure message to the sender)

case None => sender() ! Status.Failure(new KeyNotFoundException(key))
and
case o => Status.Failure(new ClassNotFoundException)

Why do we user sender() ! in the first example and not the second? Is there any difference? Does it matter?

SClientIntegrationSpec doesn't run twice

The default implementation of the SClientIntegrationSpec class gives an error if we try to run the tests twice. (port already in use).

The default template from giter8 uses TestKit and BeforeAndAfterAll to cleanly close the test class after execution. Why not use those?

code error

1. .java not found
   learning-akka/ch6/akkademaid-java/src/main/java/com/akkademy/AkkademyDb.java
   [
   import com.akkademy.japi.GetRequest;
   import com.akkademy.japi.KeyNotFoundException;
   import com.akkademy.japi.SetRequest;
   ] not found

2. file content:
   learning-akka/ch6/akkademaid-java/build.sbt
   name is [akkademy-db-scala]

Typo in "Creating an actor"

Hi, I've been reading the book on Safari Online. It's fantastic!
In section "Creating an actor" of Chapter 2, seems "variable lengle list" in the first paragraph of "Props" should be "variable length list".

Thanks.

Questions for the code example on page 112

Hey, I just went through this and for the code example on page 112:

public void postStart() {
    self().ask(new Connect(), null);
}

override def postStart = self ! connect

Shouldn't it be:

public void preStart() {
    self().tell(new Connect(), null);
}

override def preStart = self ! connect

I don't find postStart as an akka method that we can override. And the java code should use tell instead of ask.
Is it a typo or am I missing anything?

Thanks

Trouble getting akka remoting to start

I'm trying to run your code without activator. It works if I run it with sbt publishLocal and sbt run as downloaded. When I copy your build.sbt and src/ directory to another project akka remoting doesn't start. I've also added the activator and activator-launch-1.2.10.jar file but that makes no difference.

What else do I need to get this to work without activator?