Pular para o conteúdo principal

Wildfly 10 Javascript Hello World in 2 minutes

We already talked about Nashorn, JavaFX and Javascript in this blog, but today I was surprised by the announcement that Widlfly 10 supports Javascript in the server side. I should have seen before, but only after a few months it was released I saw it on twitter!

After seeing the announcements samples, I thought I had to try it and surprisingly it took less than a few minutes to have my first script running. Here are the steps I had to follow:

(I am considering you already have Java 8 installed)

  • * Download Widlfly 10: I downloaded Widlfly 10.0.0.CR4 Application Server Distribution. See more in widlfly downloads page;
$ wget http://download.jboss.org/wildfly/10.0.0.CR4/wildfly-10.0.0.CR4.zip

  • Unzip it somewhere locally: 
$ unzip wildfly-10.0.0.CR4.zip

  • Start it "quietly":
$ cd wildfly-10.0.0.CR4
& ./bin/standalone.sh > /dev/null &

  • Create the application structure in the deployments directory
$ mkdir -p standalone/deployments/app.war/WEB-INF

  • Create the only descriptor needed in your application and declare the Javascript file on it (hello.js):
$ cat standalone/deployments/app.war/WEB-INF/undertow-scripts.conf 
hello.js

  • Create the javascript file itself in the application root directory:
$ cat standalone/deployments/app.war/hello.js 
$undertow.onGet("/say-hello", function($exchange) {
return "Hello World!";
});

As you can see above, when you send a HTTP request using the GET method to the URL {host}/{app context}/say-hello it should return "Hello World!". We just have to provide the context and the function that will handle the requests.
  • Deploy the application itself:
$ touch standalone/deployments/app.war.dodeploy

  • Check if it was correctly deployed by checking the logs:
$ tail  -n 3 standalone/log/server.log 
2015-11-15 21:47:09,649 INFO  [org.jboss.as.server.deployment] (MSC service thread 1-3) WFLYSRV0027: Starting deployment of "app.war" (runtime-name: "app.war")
2015-11-15 21:47:11,600 INFO  [org.wildfly.extension.undertow] (ServerService Thread Pool -- 63) WFLYUT0021: Registered web context: /app
2015-11-15 21:47:11,654 INFO  [org.jboss.as.server] (DeploymentScanner-threads - 2) WFLYSRV0010: Deployed "app.war" (runtime-name : "app.war")

  • Finally test the application using a web browser or curl:
$ curl http://localhost:8080/app/say-hello
Hello World!


Well, that's just the beginning. You can now using Java EE services in your javascript annotation as it is described in the release announcement. 

I guess you still did not notice the best part: you don't need to recompile your application anymore, you can simply edit the javascript and touch the app.war.dodeploy file and the changes will be immediately available (after, of course, a redeploy). Stuart Douglas pointed that you can configure hot deployment and no redeploy is needed. The hot deployment configuration is described in the announcement as well and to configure it I simply created the file undertow-external-mounts.conf with the directory where my javascripts are located:


$ echo /opt/jboss/WILDFLY/wildfly-10.0.0.CR4/standalone/deployments/app.war/  > standalone/deployments/app.war/WEB-INF/undertow-external-mounts.conf

 Now if I edit any javascript file in the pointed directory I will see the changes immediately once I reach the endpoint.

If you still do not believe it is really simple, I have created a video for you!




Marcadores

Marcadores:

Comentários

Postar um comentário

Postagens mais visitadas deste blog

Dancing lights with Arduino - The idea

I have been having fun with Arduino these days! In this article I am going to show how did I use an electret mic with Arduino to create a Dancing Lights circuit. Dancing Lights   I used to be an eletronician before starting the IT college. I had my own electronics maintenance office to fix television, radios, etc. In my free time I used to create electronic projects to sell and I made a few "reais" selling a version of Dancing lights, but it was too limited: it simply animated lamps using a relay in the output of a 4017 CMOS IC. The circuit was a decimal counter  controlled by a 555. 4017 decimal counter. Source in the image When I met Arduino a few years ago, I was skeptical because I said: I can do this with IC, why should I use a microcontroller. I thought that Arduino was for kids. But now my pride is gone and I am having a lot of fun with Arduino :-) The implementation of Dancing Lights with Arduino uses an electret mic to capture the sound and light leds...
Postar um comentário
Leia mais

Simplest JavaFX ComboBox autocomplete

Based on this Brazilian community post , I've created a sample Combobox auto complete. What it basically does is: When user type with the combobox selected, it will work on a temporary string to store the typed text; Each key typed leads to the combobox to be showed and updated If backspace is type, we update the filter Each key typed shows the combo box items, when the combobox is hidden, the filter is cleaned and the tooltip is hidden:   The class code and a sample application is below. I also added the source to my personal github , sent me PR to improve it and there are a lot of things to improve, like space and accents support.
2 comentários
Leia mais

Genetic algorithms with Java

One of the most fascinating topics in computer science world is Artificial Intelligence . A subset of Artificial intelligence are the algorithms that were created inspired in the nature. In this group, we have Genetic Algorithms  (GA). Genetic Algorithms  To find out more about this topic I recommend the following MIT lecture and the Nature of Code book and videos created by Daniel Shiffman. Genetic Algorithms using Java After I remembered the basics about it, I wanted to practice, so I tried my own implementation, but I would have to write a lot of code to do what certainly others already did. So I started looking for Genetic Algorithm libraries and found Jenetics , which is a modern library that uses Java 8 concepts and APIs, and there's also JGAP . I decided to use Jenetics because the User Guide was so clear and it has no other dependency, but Java 8. The only thing I missed for Jenetics are more small examples like the ones I will show i...
Postar um comentário
Leia mais