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
Rx Java introduction
Search
SingaSUG
July 29, 2015
Technology
0
100
Rx Java introduction
Talk from Xavier Lepretre
SingaSUG
July 29, 2015
Tweet
Share
More Decks by SingaSUG
See All by SingaSUG
Java/Spring and Node.JS side by side
singasug
0
180
Migrating to microservices (Carlos Queiroz)
singasug
0
210
Docker 101 - Mario Loriedo
singasug
0
250
Docker for Java/Spring developers
singasug
0
64
Cloud Foundry and Docker
singasug
0
170
Multi dimensional scaling with CouchBase
singasug
1
100
NoSql presentation from Clarence Tauro
singasug
2
180
Spring Websockets
singasug
0
180
migrating from JSP to AngularJS
singasug
0
2.5k
Other Decks in Technology
See All in Technology
登壇ネタの見つけ方 / How to find talk topics
pinkumohikan
5
550
モバイル界のMCPを考える
naoto33
0
130
Wasm元年
askua
0
160
Claude Code Actionを使ったコード品質改善の取り組み
potix2
PRO
6
2.6k
Lambda Web Adapterについて自分なりに理解してみた
smt7174
5
130
Amazon S3標準/ S3 Tables/S3 Express One Zoneを使ったログ分析
shigeruoda
5
580
生成AIで小説を書くためにプロンプトの制約や原則について学ぶ / prompt-engineering-for-ai-fiction
nwiizo
4
3k
TechLION vol.41~MySQLユーザ会のほうから来ました / techlion41_mysql
sakaik
0
200
米国国防総省のDevSecOpsライフサイクルをAWSのセキュリティサービスとOSSで実現
syoshie
2
1.2k
Tech-Verse 2025 Global CTO Session
lycorptech_jp
PRO
0
960
生成AI時代の開発組織・技術・プロセス 〜 ログラスの挑戦と考察 〜
itohiro73
1
340
AIの最新技術&テーマをつまんで紹介&フリートークするシリーズ #1 量子機械学習の入門
tkhresk
0
140
Featured
See All Featured
Chrome DevTools: State of the Union 2024 - Debugging React & Beyond
addyosmani
7
710
Thoughts on Productivity
jonyablonski
69
4.7k
The Art of Programming - Codeland 2020
erikaheidi
54
13k
Responsive Adventures: Dirty Tricks From The Dark Corners of Front-End
smashingmag
252
21k
Cheating the UX When There Is Nothing More to Optimize - PixelPioneers
stephaniewalter
281
13k
Design and Strategy: How to Deal with People Who Don’t "Get" Design
morganepeng
130
19k
Become a Pro
speakerdeck
PRO
28
5.4k
10 Git Anti Patterns You Should be Aware of
lemiorhan
PRO
657
60k
Git: the NoSQL Database
bkeepers
PRO
430
65k
The Cost Of JavaScript in 2023
addyosmani
51
8.5k
Measuring & Analyzing Core Web Vitals
bluesmoon
7
490
Building Adaptive Systems
keathley
43
2.6k
Transcript
RxJava Intro Functional reactive programming By Xavier Lepretre
What we want What we know
Imperative and synchronous var a = fetch(key); var b =
transform(a); var c = transformAgain(b); return process(c);
Asynchronous with callbacks fetch(key, new Callback() { void onReceived(a) {
transform(a, new Callback() { void onFinished(b) ... }); } });
Futures future = executor.submit(new Callback() { Object call() { return
doLongExecution(); } }); a = future.get();
Nice to have, workflow description When done, do that fetch(key).then(a
-> transform(a)) .then(b -> transformAgain(b)) .then(c -> process(c)) .then(d -> use(d));
Important classes
Observable<MyType> - like an object(s) pipe - no limit on
number of objects piped - also pipes Throwable - signals when no more object, completed - can have many observers, like a multicast
Observer<MyType> - will receive: - the objects - the errors
- the completed signal - can subscribe to many observables
Subscription - a handle to an observer subscribed to an
observable - call .unsubscribe() when you no longer need to receive
Action1<MyType> { void call(MyType obj); } - 1 because it
takes 1 parameter - There are Action2 … Action9
Func1<MyType, NextType> { public NextType call(MyType obj); } - 1
because it takes 1 parameter - There are Func2 … Func9
Important operations
.map(new Func1<A,B>(){}) - works on an object traveling along the
pipe - transforms from one type to another - to be used when the transformation is synchronous - example: convert
None
.doOnNext(new Action1<A>(){}) - Works on a object from the pipe
- Leaves the object unchanged - Example: save in cache, log
None
.flatMap(Func1<A, Observable<B>>) - Works on an object traveling along the
pipe - Transforms from one type to another - To be used when the transformation is asynchronous - Example: network fetch, open dialog
None
Advantages - Unsubscription handles removing callback - Method can describe
a subset of workflow
Create your own: OnSubscribe<> - Change callbacks into objects in
pipeline - Know when to call onCompleted() - subscribeOn() - Subscriptions.create() - AndroidSubscriptions. unsubscribeInUiThread
Pitfalls - Forgot to .subscribe() - subscriptionList.unsubscribe(). Do not reuse
- forgot observeOn(AndroidSchedulers. mainThread()) - callbacks may not show as used if you use retrolambda
Code Example https://github.com/xavierlepretre/rx-example
- All code shown is on client - Retrofit creates
Observables -
- workflow pieces in methods: for dialog, no need to
know next step - .onErrorResumeNext() to avoid break on less important elements - .flatMap() to show and wait for dialog - .publish() and .connect() to share Observable - SimpleAlertDialogOperator to convert a dialog into Observable