DDevelopment & Design

Friday hackathon

Every month we have a Friday Hackathon, where we can code or create anything we want. That’s for the purpose of evaluating new technologies, doing crazy stuff or just having fun.

Beneath that we develop our skills and gain new experience.

Today we have 5 teams, that are doing following projects in various technologies:

  • Ping-pong scoring – we play ping pong a lot, so an app is a must! – Java (Dropwizard), Mongo
  • TouK’s library – we have dozens of books but currently we have a chaos who lends what – Clojure
  • ToukApi – access all internal data (about people, salaries, holidays, auth, projects people are in etc) through REST api – vert.x
  • ID / Drivers license recognition on Mobile – just shoot a photo of an ID and have all data and photo in a few seconds – Kotlin, Android
  • jaIde – I’m going for a sandwich – you can inform other employees that you go for a morning sandwich – that means – Mr Sandwich has just arrived at the kitchen – it’s like a snowball, the more people go for a sandwich the more confident you can be that there are actually sandwiches waiting :) – Swift/Scala/Java

At 4:30 PM we have hackathon summary. Let’s see what projects we will manage to accomplish…

 

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DDevelopment & Design

Grails render as JSON catch

One of a reasons your controller doesn't render a proper response in JSON format might be wrong package name that you use. It is easy to overlook. Import are on top of a file, you look at your code and everything seems to be fine. Except response is still not in JSON format.

Consider this simple controller:

class RestJsonCatchController {
def grailsJson() {
render([first: 'foo', second: 5] as grails.converters.JSON)
    }

def netSfJson() {
render([first: 'foo', second: 5] as net.sf.json.JSON)
    }
}

And now, with finger crossed... We have a winner!

$ curl localhost:8080/example/restJsonCatch/grailsJson
{"first":"foo","second":5}
$ curl localhost:8080/example/restJsonCatch/netSfJson
{first=foo, second=5}

As you can see only grails.converters.JSON converts your response to JSON format. There is no such converter for net.sf.json.JSON, so Grails has no converter to apply and it renders Map normally.

Conclusion: always carefully look at your imports if you're working with JSON in Grails!

Edit: Burt suggested that this is a bug. I've submitted JIRA issue here: GRAILS-9622 render as class that is not a codec should throw exception