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
·
SiteGround - Reliable hosting with speed, security, and support you can count on.
→
HASUNUMA Kenji
April 20, 2016
Programming
42
0
Share
Fundamental Java
HASUNUMA Kenji
April 20, 2016
More Decks by HASUNUMA Kenji
See All by HASUNUMA Kenji
Jakarta EE: The First Parts
khasunuma
0
57
Life of our small product
khasunuma
0
46
How to adapt MicroProfile API for generic Web applications
khasunuma
0
43
Overviewing Admin Console
khasunuma
0
42
Introduction to MicroProfile Metrics
khasunuma
0
65
Basic method for Java EE Web Profile
khasunuma
0
40
Introduction to JCA and MDB
khasunuma
0
92
Collections Framework Begineers Guide 2
khasunuma
0
81
JLS myths ~ if-then-else statement ~
khasunuma
0
52
Other Decks in Programming
See All in Programming
The Less-Told Story of Socket Timeouts
coe401_
3
450
UIの境界線をデザインする | React Tokyo #15 メイントーク
sasagar
2
370
의존성 주입과 모듈화
fornewid
0
150
ふりがな Deep Dive try! Swift Tokyo 2026
watura
0
230
10年分の技術的負債、完済へ ― Claude Code主導のAI駆動開発でスポーツブルを丸ごとリプレイスした話
takuya_houshima
0
2.6k
Don't Prompt Harder, Structure Better
kitasuke
0
770
アーキテクチャモダナイゼーションとは何か
nwiizo
19
5.3k
Agentic Elixir
whatyouhide
0
350
t *testing.T は どこからやってくるの?
otakakot
1
690
ハーネスエンジニアリングにどう向き合うか 〜ルールファイルを超えて開発プロセスを設計する〜 / How to approach harness engineering
rkaga
24
14k
レガシーPHP転生 〜父がドメインエキスパートだったのでDDD+Claude Codeでチート開発します〜
panda_program
0
1k
年間50登壇、単著出版、雑誌寄稿、Podcast出演、YouTube、CM、カンファレンス主催……全部やってみたので面白さ等を比較してみよう / I’ve tried them all, so let’s compare how interesting they are.
nrslib
4
790
Featured
See All Featured
Measuring & Analyzing Core Web Vitals
bluesmoon
9
810
What does AI have to do with Human Rights?
axbom
PRO
1
2.1k
B2B Lead Gen: Tactics, Traps & Triumph
marketingsoph
0
100
16th Malabo Montpellier Forum Presentation
akademiya2063
PRO
0
110
ReactJS: Keep Simple. Everything can be a component!
pedronauck
666
130k
Java REST API Framework Comparison - PWX 2021
mraible
34
9.3k
Max Prin - Stacking Signals: How International SEO Comes Together (And Falls Apart)
techseoconnect
PRO
0
150
How STYLIGHT went responsive
nonsquared
100
6.1k
CSS Pre-Processors: Stylus, Less & Sass
bermonpainter
360
30k
The Myth of the Modular Monolith - Day 2 Keynote - Rails World 2024
eileencodes
27
3.4k
Impact Scores and Hybrid Strategies: The future of link building
tamaranovitovic
0
260
StorybookのUI Testing Handbookを読んだ
zakiyama
31
6.7k
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