Category: Programming

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3 months of JRebel

Found this post in draft status. Seemed to have forgotten to publish it. Here it goes.

I’ve used JRebel for 3 months. The demo license has come to an end in January and I’m already missing it.

In 3 months time JRebel saved my about 3 days, that is a day a month. Now I must confess, I haven’t had to start up webapps for at least one month and another month was 3 weeks of holidays . So these stats actually count for only a month and a half, which makes them even look better!

Currently I’m without JRebel, restarting the jersey/spring web applications every 2 deploys. I’m trying to advertise the usage of JRebel a bit, but with the crisis it seems there is no money. If I only was a manager …

Why should you use JRebel? That has been summed up before see here and here

Wouldn’t everyone want a tool like that?

I would like to see LiveRebel in action where I work now, but don’t think the workplace wants it 🙁

note: I’m not affiliated with zeroturnaround in any way!

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Akka

Something else I picked up at Devoxx is Akka. I had heard of it before. Following a session about it renewed my interest.

Akka is a framework created to address problems in creating highly scalable and concurrent software. It is also the name of a mountain in Sweden and a Goddess.
Akka’s Keywords are: concurrency, scalability, fault-tolerance
Akka tries to address system overloads and is currently used in finance, telecom simulation, e-commerce and betting system. All applications that need a lot of event driven actions.
If you have heard of the Play framework, it will be using Akka internally from 2.0 on.

An Akka application uses Actors. What’s an actor: an object that encapsulates state and behaviour. Actors talk to each other as like they send mail. They don’t wait for each other. ( e.g. an actor could be every user in a mmorpg)

Some actor features: Continue reading “Akka”

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Stop sleeping, start awaiting

On Devoxx there was a quicky session named ‘Stop sleeping, start awaiting’

The speaker presented Awaitility. A test-framework for helping you out waiting on objects. Mainly usable for testing asynchronous code in unit testing. A unit test does not wait for code to be executed, developers tend to use Object.sleep(xxx) but this will not always work. On some systems the xxx needs more milliseconds then on others. In the end you’ll be waiting ( rather sleeping) while all the tests that have sleep() run. The whole testsuite will go very slow.

Awaitility is a framework to help you wait for code to be executed,
It goes like:

await().untilCall(wrappedCallMethod).statusOf(xxx).is(OKAY);

It’s like a mocking framework. Personally I do the same with mockito and java.util.concurrency waiting and locking classes. But perhaps Awaitility will make you create the tests faster.

This is certainly one framework I will try out!