Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Two Scoops of Scala
Search
Kārlis Lauva
April 09, 2014
Programming
0
100
Two Scoops of Scala
April tech talk at FullContact
Kārlis Lauva
April 09, 2014
Tweet
Share
More Decks by Kārlis Lauva
See All by Kārlis Lauva
Let's talk about PureScript
karlis
0
78
Going Full Monty with full.monty
karlis
1
93
The Transatlantic Struggle
karlis
0
66
Valsts pārvaldes atvērto datu semantiskās integrācijas procesi
karlis
1
180
Tornado in 1 Hour (or Less)
karlis
4
190
Other Decks in Programming
See All in Programming
CSC305 Lecture 08
javiergs
PRO
0
280
Server Side Kotlin Meetup vol.16: 内部動作を理解して ハイパフォーマンスなサーバサイド Kotlin アプリケーションを書こう
ternbusty
3
260
The Past, Present, and Future of Enterprise Java
ivargrimstad
0
520
O Que É e Como Funciona o PHP-FPM?
marcelgsantos
0
210
GC25 Recap: The Code You Reviewed is Not the Code You Built / #newt_gophercon_tour
mazrean
0
120
「ちょっと古いから」って避けてた技術書、今だからこそ読もう
mottyzzz
12
7.2k
NIKKEI Tech Talk#38
cipepser
0
290
bootcamp2025_バックエンド研修_WebAPIサーバ作成.pdf
geniee_inc
0
140
Devvox Belgium - Agentic AI Patterns
kdubois
1
150
Pythonに漸進的に型をつける
nealle
1
130
Towards Transactional Buffering of CDC Events @ Flink Forward 2025 Barcelona Spain
hpgrahsl
0
120
三者三様 宣言的UI
kkagurazaka
0
260
Featured
See All Featured
RailsConf 2023
tenderlove
30
1.3k
How GitHub (no longer) Works
holman
315
140k
Optimizing for Happiness
mojombo
379
70k
Performance Is Good for Brains [We Love Speed 2024]
tammyeverts
12
1.2k
JavaScript: Past, Present, and Future - NDC Porto 2020
reverentgeek
52
5.7k
What’s in a name? Adding method to the madness
productmarketing
PRO
24
3.7k
Let's Do A Bunch of Simple Stuff to Make Websites Faster
chriscoyier
508
140k
Designing for humans not robots
tammielis
254
26k
[RailsConf 2023] Rails as a piece of cake
palkan
57
5.9k
Why You Should Never Use an ORM
jnunemaker
PRO
59
9.6k
The Illustrated Children's Guide to Kubernetes
chrisshort
49
51k
Save Time (by Creating Custom Rails Generators)
garrettdimon
PRO
32
1.7k
Transcript
Two scoops of Scala & Unfiltered April 2014 FullContact techTalk
@skazhy
Scala? • object oriented and functional programming language • Type
safe • Runs on JVM
Unfiltered? • A toolkit for HTTP in Scala • Really,
really modular • Works with Netty and Jetty • Built for meetup.com realtime API • Makes good use of Scala's idioms
Toolchain • SBT - Scala Build Tool • Best conventions
from Maven world • Iterative development in SBT shell
My setup • IntelliJ + SBT console(s) inside tmux •
IntelliJ 13 has SBT support baked in
Deployment • Works great with Jenkins & Asgard • Minimal
configuration tweaks needed (wait for the next slide)
• A tool for fetching templates for Scala projects •
g8 skazhy/unfiltered-netty-rx • All SBT plugins for deployment and IntelliJ are included Bootstrapping with giter8
Using opinionated RESTful frameworks for microservices?
None
Example time!
object MyPlan extends cycle.Plan with cycle.ThreadPool with ServerErrorResponse { def
intent = { case GET(Path("/")) => ResponseString("Hello!") case OPTIONS(_) => Created ~> Location("/foo") case _ => NotFound } } unfiltered.netty.Http(1337).handler(MyPlan).run()
An Intent is a partial function that pattern matches HTTP
requests
A Plan is a binding between intent and the underlying
interface
Pattern matching • Decomposing data structures to extract certain fields
or validate them • Really powerful in Scala • “routing” mechanism in Unfiltered
None
Match on request methods • Use builtins: GET(_) POST(_) PATCH(_)
• Or define your own: object SPACEJUMP extends Method("SPACEJUMP")
What happens under the hood? class Method(method: String) { def
unapply[T](req: HttpRequest[T]) = if (req.method.equalsIgnoreCase(method)) Some(req) else None } object POST extends Method("POST")
Match on request headers BasicAuth(username, password) UserAgent("Cobook")
...on URN Path("/foobar") Path(Seg("contactLists" :: "v2" :: listId :: Nil))
// Will extract /contactLists/v2/1234
...or query parameters object AccountIdParam extends Params.Extract("numericId", Params.first ~> Params.nonempty
~> Params.long) PATCH(Params(AccountIdParam(accountId))) // Will extract 1234 from PATCH /foo?numericId=1234
None
function composition!
Responses are composable case _ => Unauthorized ~> ResponseString("No pasaran")
~> ResponseHeader("WWW-Authenticate", "Basic realm=foo")
• HTTP requests are stateless • HTTP responses are side
effects
Async made easy case req @ GET(Path("/async")) => val futureOp
= asyncOperation futureOp.onSuccess { case result => req.respond(Ok ~> ResponseString(result)) } futureOp.onFailure { case _ => req.respond(InternalServerError) }
Unfiltered plays well with RxJava too
case req @ GET(Path("/reactive")) => observableOp.subscribe( result => req.respond(ResponseString(result)) _
=> req.respond(InternalServerError) )
What about testing?
• Separate library for testing with Specs2 • Mocking with
Mockito • Comes bundled with the giter8 template unfiltered-specs2
object OperationPostSpec extends Specification { "PATCH /foo" should { lazy
val r = Http(url((host \ "foo").PATCH)) lazy val response = r() "return HTTP 200" in { response.getResponseStatus mustEqual 200 } } }
Consider using Unfiltered when you... • need an async &
lightweight HTTP service • Have separate business logic • Want to leverage the λ-force
Questions?