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
·
Your Podcast. Everywhere. Effortlessly.
Share. Educate. Inspire. Entertain. You do you. We'll handle the rest.
→
HASUNUMA Kenji
April 20, 2016
Programming
0
37
Fundamental Java
HASUNUMA Kenji
April 20, 2016
Tweet
Share
More Decks by HASUNUMA Kenji
See All by HASUNUMA Kenji
Jakarta EE: The First Parts
khasunuma
0
54
Life of our small product
khasunuma
0
45
How to adapt MicroProfile API for generic Web applications
khasunuma
0
41
Overviewing Admin Console
khasunuma
0
40
Introduction to MicroProfile Metrics
khasunuma
0
63
Basic method for Java EE Web Profile
khasunuma
0
38
Introduction to JCA and MDB
khasunuma
0
91
Collections Framework Begineers Guide 2
khasunuma
0
80
JLS myths ~ if-then-else statement ~
khasunuma
0
46
Other Decks in Programming
See All in Programming
GC言語のWasm化とComponent Modelサポートの実践と課題 - Scalaの場合
tanishiking
0
130
20260228_JAWS_Beginner_Kansai
takuyay0ne
5
610
実践ハーネスエンジニアリング #MOSHTech
kajitack
7
3.1k
生成 AI 時代のスナップショットテストってやつを見せてあげますよ(α版)
ojun9
0
300
Linux Kernelの1文字のミスで 権限昇格ができた話
rqda
0
2.1k
Feature Toggle は捨てやすく使おう
gennei
0
330
Codex の「自走力」を高める
yorifuji
0
1.3k
AI時代の脳疲弊と向き合う ~言語学としてのPHP~
sakuraikotone
1
1.5k
Ruby and LLM Ecosystem 2nd
koic
1
1.3k
Nostalgia Meets Technology: Super Mario with TypeScript
manfredsteyer
PRO
0
110
Reactive ❤️ Loom: A Forbidden Love Story
franz1981
2
160
RailsのValidatesをSwift Macrosで再現してみた
hokuron
0
130
Featured
See All Featured
Visualizing Your Data: Incorporating Mongo into Loggly Infrastructure
mongodb
49
9.9k
What's in a price? How to price your products and services
michaelherold
247
13k
Breaking role norms: Why Content Design is so much more than writing copy - Taylor Woolridge
uxyall
0
220
How to build a perfect <img>
jonoalderson
1
5.3k
Measuring Dark Social's Impact On Conversion and Attribution
stephenakadiri
1
160
Practical Orchestrator
shlominoach
191
11k
Paper Plane (Part 1)
katiecoart
PRO
0
5.8k
Exploring the relationship between traditional SERPs and Gen AI search
raygrieselhuber
PRO
2
3.7k
Designing Powerful Visuals for Engaging Learning
tmiket
0
290
The Success of Rails: Ensuring Growth for the Next 100 Years
eileencodes
47
8k
Joys of Absence: A Defence of Solitary Play
codingconduct
1
320
XXLCSS - How to scale CSS and keep your sanity
sugarenia
249
1.3M
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