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
HASUNUMA Kenji
April 20, 2016
Programming
0
15
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
33
Life of our small product
khasunuma
0
17
How to adapt MicroProfile API for generic Web applications
khasunuma
0
18
Overviewing Admin Console
khasunuma
0
18
Introduction to MicroProfile Metrics
khasunuma
0
40
Basic method for Java EE Web Profile
khasunuma
0
17
Introduction to JCA and MDB
khasunuma
0
49
Collections Framework Begineers Guide 2
khasunuma
0
55
JLS myths ~ if-then-else statement ~
khasunuma
0
18
Other Decks in Programming
See All in Programming
Understand the mechanism! Let's do screenshots tests of Compose Previews with various variations / 仕組みから理解する!Composeプレビューを様々なバリエーションでスクリーンショットテストしよう
sumio
3
620
[DroidKaigi 2024] Android ViewからJetpack Composeへ 〜Jetpack Compose移行のすゝめ〜 / From Android View to Jetpack Compose: A Guide to Migration
syarihu
1
550
connect-go で面倒くささと戦う / 2024-08-27 #newmo_layerx_go
izumin5210
2
640
Boost Performance and Developer Productivity with Jakarta EE 11
ivargrimstad
0
440
How to Break into Reading Open Source
kaspth
2
210
事業フェーズの変化に対応する 開発生産性向上のゼロイチ
masaygggg
0
200
The Sequel to a Dream of Ruby Parser's Grammar
ydah
1
220
Amazon BedrockでサーバレスなAIお料理ボットを作成する!!
tosuri13
0
220
意外とフォントが大事だった話 / Font Issues on Internationalization
fumi23
0
110
Rechartsで楽にゴリゴリにカスタマイズする!
10tera
1
170
サーバーレスで負荷試験!Step Functions + Lambdaを使ったk6の分散実行
shuntakahashi
6
1.5k
僕が思い描くTypeScriptの未来を勝手に先取りする
yukukotani
9
2.4k
Featured
See All Featured
Visualizing Your Data: Incorporating Mongo into Loggly Infrastructure
mongodb
38
9.2k
Fontdeck: Realign not Redesign
paulrobertlloyd
80
5.1k
The MySQL Ecosystem @ GitHub 2015
samlambert
250
12k
The Art of Programming - Codeland 2020
erikaheidi
48
13k
The Pragmatic Product Professional
lauravandoore
31
6.2k
Music & Morning Musume
bryan
46
6k
Pencils Down: Stop Designing & Start Developing
hursman
119
11k
Six Lessons from altMBA
skipperchong
26
3.3k
Speed Design
sergeychernyshev
22
430
Building an army of robots
kneath
302
42k
Designing on Purpose - Digital PM Summit 2013
jponch
114
6.8k
The Mythical Team-Month
searls
218
43k
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