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
Fundamental Java
Search
Sponsored
·
Ship Features Fearlessly
Turn features on and off without deploys. Used by thousands of Ruby developers.
→
HASUNUMA Kenji
April 20, 2016
Programming
48
0
Share
Embed
Copy iframe code
Copy JS code
Copy link
Start on current slide
Fundamental Java
HASUNUMA Kenji
April 20, 2016
More Decks by HASUNUMA Kenji
See All by HASUNUMA Kenji
Jakarta EE: The First Parts
khasunuma
0
67
Life of our small product
khasunuma
0
49
How to adapt MicroProfile API for generic Web applications
khasunuma
0
47
Overviewing Admin Console
khasunuma
0
47
Introduction to MicroProfile Metrics
khasunuma
0
74
Basic method for Java EE Web Profile
khasunuma
0
48
Introduction to JCA and MDB
khasunuma
0
100
Collections Framework Begineers Guide 2
khasunuma
0
88
JLS myths ~ if-then-else statement ~
khasunuma
0
70
Other Decks in Programming
See All in Programming
これからAgentCoreを触る方へトレンドはGatewayです
har1101
6
500
PHPだって関数型したい 〜できること、できないこと〜 / fp-in-php
jsoizo
0
210
【SRE NEXT 2026 Lunch Session】一人目専任SREの立ち上げを加速する ― AIと進めたオンボーディングで2分を0.04秒にした話
pkshadeck
PRO
0
2.7k
【やさしく解説 設計編 #1】「ドメイン駆動」と「実装駆動」ってなに? 〜設計の考え方を、たとえ話で学ぼう〜
panda728
PRO
1
120
関数型プログラミングのメリットって何だろう?
wanko_it
0
180
型も通る、synthも通る、それでも危ない 〜AIのCDKの権限とコストを機械で検証する〜 / It Passes Type Checks, It Passes Synth Checks, but It’s Still Risky — Automatically Verifying Permissions and Costs in AI’s CDK —
seike460
PRO
1
340
【やさしく解説 設計編・中級 #6】良いアーキテクチャとは ~ 一本の登り道の、行き先 ~
panda728
PRO
0
170
yield再入門 #phpcon
o0h
PRO
0
450
Laravel Boostに学ぶ、AIにPHPを書かせる技術 〜OSSの実装から蒸留するエージェント制御の王道〜
kentaroutakeda
3
450
継続モナドとリアクティブプログラミング
yukikurage
3
610
【やさしく解説 設計編 #0】DDDのコード、読めるのに分からない人へ
panda728
PRO
2
270
霧の中の代数的エフェクト
funnyycat
1
390
Featured
See All Featured
Jamie Indigo - Trashchat’s Guide to Black Boxes: Technical SEO Tactics for LLMs
techseoconnect
PRO
0
360
Writing Fast Ruby
sferik
630
63k
Reflections from 52 weeks, 52 projects
jeffersonlam
356
21k
Intergalactic Javascript Robots from Outer Space
tanoku
273
27k
Exploring the Power of Turbo Streams & Action Cable | RailsConf2023
kevinliebholz
37
6.5k
Lightning talk: Run Django tests with GitHub Actions
sabderemane
0
220
<Decoding/> the Language of Devs - We Love SEO 2024
nikkihalliwell
1
280
Paper Plane (Part 1)
katiecoart
PRO
1
9.7k
The Straight Up "How To Draw Better" Workshop
denniskardys
239
140k
HU Berlin: Industrial-Strength Natural Language Processing with spaCy and Prodigy
inesmontani
PRO
0
530
Docker and Python
trallard
47
4k
More Than Pixels: Becoming A User Experience Designer
marktimemedia
3
460
Transcript
Fundamental Java HASUNUMA Kenji Vice president, GlassFish Users Group Japan
[email protected]
Twitter: @btnrouge
What’s Java?
Javaͷಛ • Φʔϓϯͳن֨Ͱ͋Δ • ৗʹਐԽ͍ͯ͠Δ • ޓੑΛॏࢹ͍ͯ͠Δ
JavaΦʔϓϯن֨ • ݴޠɺඪ४APIɺԾϚγϯ༷ • Java Community ProcessͰඪ४Խ • ݱࡏΦʔϓϯιʔε (GPLv2)
wWrite Once, Run Anywhere wݴޠϨϕϧͰϚϧνεϨουରԠ wݫ֨ͳྫ֎ॲཧػߏ w6OJDPEFΛશ໘తʹ࠾༻
Write Once, Run Anywhere • OSɺJava VM࣮ʹґଘ͠ͳ͍ • ݹ͍ίʔυ͕࠷৽ͷJavaͰಈ͘ •
Blu-ray͔ΒڊେγεςϜ·Ͱ
ॳ04ͷࠩҟΛ+BWB7.͕ٵऩ͢Δ ݱࡏ+BWB7.͕ଟݴޠͷڞ௨ج൫
Essential Java
JavaͷΤίγεςϜ
ΫϥεͱΠϯλϑΣʔε
!
! Ϋϥεͷܧঝ
" #
" Polymorphismͱ
$%& '&( ( )&%%%
ϓϩηεͱεϨου
$%& '&( ( )&%%%
$%* $%* $%* + + ϓϩηεͱεϨου
, "- # ./0 , 0 #- ./0 " " " " " " -""1 +BWBͷೖग़ྗ 4USFBN ݱࡏͰจࣈྻσʔλʹಛԽͨ͠3FBEFS8SJUFSɺ ߴ*0Λ࣮ݱ͢Δ$IBOOFMΑ͘ΘΕ͍ͯΔ
+BWBͷύοέʔδ
Ϋϥε໊ͷදهํ๏ wݪଇύοέʔδΛؚΉશ໊ ྫ java.util.List wimportએݴಛఆͷύοέʔδΛলུՄ ํ๏ import java.util.List; ํ๏ import
java.util.*; wjava.langʜৗʹύοέʔδΛলུՄ
+BWBΫϥεͷಉҰੑ • Ϋϥε໊͕ಉҰͰ͋Δ • ύοέʔδ໊͕શʹҰக͍ͯ͠Δ • ಉ͡Ϋϥεϩʔμʔ͔ΒಡΈࠐ·Εͨ
Java Core Parts
ΫϥεͱΦϒδΣΫτ • ΫϥεఆٛͷΈ…࣮ମ͕ͳ͍ • ΦϒδΣΫτ(Πϯελϯε) …Ϋϥε͔Β࡞࣮ͨ͠ମͷ͜ͱ • ϑΟʔϧυͱϝιουΦϒδΣΫτʹ ଐ͢Δ(㱻staticΫϥεʹଐ͢Δ)
java.lang.Object • JavaͷશΫϥεͷεʔύʔΫϥε • ΫϥεͷࠜװʹؔΘΔϝιουΛ࣋ͭ • ϓϦϛςΟϒܕʹରͯ͠ϦϑΝϨϯεܕ ͱݺΕΔ͜ͱ͋Δ
java.lang.Object ͷϝιου equals ಉҰνΣοΫʹ͏ ※ݪଇͱͯ͠ΦʔόʔϥΠυ͢Δ hashCode toString จࣈྻදݱΛฦ͢ ※༻్༷ʑ wait
εϨου੍ޚ༻ϝιου ※௨ৗConcurrency UtilitiesΛܦ༝ ͯ͠༻͢Δ(ΦʔόʔϥΠυෆՄ) notify notifyAll clone ίϐʔ(࠷ۙΘΕͳ͍) finalize ޙॲཧ(௨ৗΦʔόʔϥΠυ͠ͳ͍)
Object o = new Object();
Object o = new Object();
Object o = new Object(); ӈลͱಉ͡Ϋϥε PS εʔύʔΫϥε PS ࣮ΠϯλϑΣʔε
Object o = new ArrayList();
Ωϟετ Object o = new ArrayList(); • objͷఆٛObjectɺ࣮ମArrayList • ΞΫηεఆٛΛ௨ͯ͡ߦ͏
• ࣮ମͷΞΫηεˠΩϟετ ArrayList list = (ArrayList) o; w Ωϟετ=αϒΫϥεͷఆٛͰΞΫηε w Ωϟετޙ࣮ମʹΞΫηεՄೳ
ϓϦϛςΟϒܕ • ΫϥεͰͳ͍σʔλܕ • ରԠ͢ΔΫϥε(ϥούʔ)Λ࣋ͭ • auto-boxing/unboxing: ϓϦϛςΟϒܕͱϥούʔͷ૬ޓม
ϓϦϛςΟϒܕ ϥούʔΫϥε boolean Boolean byte Byte char Character short Short
int Integer long Long float Float double Double
ྻ • ಉ͡ΫϥεorϓϦϛςΟϒܕͷ࿈ଓ • ԋࢉࢠ [ ] ͰཁૉʹΞΫηε͢Δ • ෦తʹjava.lang.ArrayΫϥε
Object[ ] o = new Object[8]; P0CKFDUͷྻ ཁૉࢦఆ͠ͳ͍ ྻͷཁૉ ඞͣఆޙͰมߋෆՄ
ྻͷ߹ɺࠨลͱӈลಉ͡Ϋϥε
ͦͷଞͷॏཁͳτϐοΫ • Generics (J2SE 5.0) • Annotation (J2SE 5.0) •
Project Coin (Java SE 7) • Collections Framework (J2SE 1.2) • New I/O (J2SE 1.4 & Java SE 7) • Concurrency Utilitites (J2SE 5.0 & Java SE 7)
Fundamental Java HASUNUMA Kenji
[email protected]
Twitter: @btnrouge