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
#渋谷java あなたと乱数生成とJava
Search
KOMIYA Atsushi
March 07, 2015
Programming
1
1.7k
#渋谷java あなたと乱数生成とJava
第十回 #渋谷java
http://shibuya-java.connpass.com/event/11574/
での発表資料です。Java で乱数生成するときのお話をしました。
KOMIYA Atsushi
March 07, 2015
Tweet
Share
More Decks by KOMIYA Atsushi
See All by KOMIYA Atsushi
#JJUG Java における乱数生成器とのつき合い方
komiya_atsushi
5
5.3k
#JJUG Fork/Join フレームワークを効率的に正しく使いたい
komiya_atsushi
0
510
[#JSUG] SmartNews における container friendly な Spring Boot アプリケーション開発
komiya_atsushi
1
11k
Java のデータ圧縮ライブラリを極める #jjug_ccc #ccc_c7
komiya_atsushi
4
5k
#devsumi 自然言語処理・機械学習によるファクトチェック業務の支援
komiya_atsushi
1
4.5k
SmartNews Ads における機械学習の活用とその運用 #mlops
komiya_atsushi
3
19k
GBDT によるクリック率予測を高速化したい #オレシカナイト vol.4
komiya_atsushi
5
1.3k
Maven central repository の artifact をランキングする #渋谷java
komiya_atsushi
0
1.4k
確率的データ構造を Java で扱いたい! #JJUG
komiya_atsushi
6
2.3k
Other Decks in Programming
See All in Programming
Modern Angular with Signals and Signal Store:New Rules for Your Architecture @enterJS Advanced Angular Day 2025
manfredsteyer
PRO
0
220
A full stack side project webapp all in Kotlin (KotlinConf 2025)
dankim
0
120
XP, Testing and ninja testing
m_seki
3
240
0626 Findy Product Manager LT Night_高田スライド_speaker deck用
mana_takada
0
170
なんとなくわかった気になるブロックテーマ入門/contents.nagoya 2025 6.28
chiilog
1
270
Systèmes distribués, pour le meilleur et pour le pire - BreizhCamp 2025 - Conférence
slecache
0
120
今ならAmazon ECSのサービス間通信をどう選ぶか / Selection of ECS Interservice Communication 2025
tkikuc
21
4k
Claude Code + Container Use と Cursor で作る ローカル並列開発環境のススメ / ccc local dev
kaelaela
9
5.1k
PHPで始める振る舞い駆動開発(Behaviour-Driven Development)
ohmori_yusuke
2
390
iOS 26にアップデートすると実機でのHot Reloadができない?
umigishiaoi
0
130
GitHub Copilot and GitHub Codespaces Hands-on
ymd65536
2
150
5つのアンチパターンから学ぶLT設計
narihara
1
170
Featured
See All Featured
KATA
mclloyd
30
14k
Practical Tips for Bootstrapping Information Extraction Pipelines
honnibal
PRO
20
1.3k
Typedesign – Prime Four
hannesfritz
42
2.7k
Easily Structure & Communicate Ideas using Wireframe
afnizarnur
194
16k
Evolution of real-time – Irina Nazarova, EuRuKo, 2024
irinanazarova
8
820
CoffeeScript is Beautiful & I Never Want to Write Plain JavaScript Again
sstephenson
161
15k
RailsConf 2023
tenderlove
30
1.1k
Bootstrapping a Software Product
garrettdimon
PRO
307
110k
Rails Girls Zürich Keynote
gr2m
95
14k
The Power of CSS Pseudo Elements
geoffreycrofte
77
5.9k
Sharpening the Axe: The Primacy of Toolmaking
bcantrill
44
2.4k
Chrome DevTools: State of the Union 2024 - Debugging React & Beyond
addyosmani
7
740
Transcript
͋ͳͨͱཚੜͱ Java ୈेճ #ौ୩java 2015-03-07 @komiya_atsushi
͓·ͩΕ ʢ͓લ୭Αʁʣ
,0.*:""UTVTIJ !LPNJZB@BUTVTIJ
None
Ad server and machine learning with Java
Random Number Generator
java.util.Random
None
Random classes provided by JDK
Random classes provided by JDK • java.util.Random • java.security.SecureRandom •
SecureRandom.getInstance("SHA1PRNG") • java.util.concurrent.ThreadLocalRandom • ThreadLocalRandom.current()
Random classes provided by commons-math3
Random classes provided by commons-math3 • MersenneTwister • most popular
(?) random number generator • Well44497a • longer period than Mersenne Twister • ISAACRandom • a fast cryptographic pseudo-random number generator
Random classes provided by commons-math3 • RandomDataGenerator supports sampling from
various distributions • Beta / Binomial / Cauchy / ChiSquare / Exponential / F / Gamma / Hypergeometric / Pascal / Poisson / T / Weibull / Zipf • java.util.Random only supports sampling from Gaussian (normal distribution)
Comparisons
Concurrency of Random and ThreadLocalRandom
Concurrency of Random and ThreadLocalRandom 5ISFBE-PDBM3BOEPNJTBXFTPNF
Latency of 200,000,000 times random number generation
Latency of 200,000,000 times random number generation .FSTFOOF5XJTUFS JTGBTU 3BOEPNJTOPU
GBTU
Conclusion
If you need… • high concurrency one • use ThreadLocalRandom
• very long-period & high quality one • use Well44497a • long-period & fast one • use MersenneTwister • cryptographically secure one • use SecureRandom
Thanks! Any questions?
8&`3&)*3*/( IUUQTKPCTGPSLXFMMDPNTNBSUOFXT PSDPOUBDUNF