Jshell로 여유롭게 놀았어요.

개요

배경.

대상

준비물

환경 구조

docker run -it openjdk:11 jshell

일단 한번 해보도록 하겠습니다.

jshell> String hoge = "hoge"
hoge ==> "hoge"

/vars

jshell> /vars
|    String hoge = "hoge"
|    List<String> list = []
|    String test = "test"

/ imports 두드리기

jshell> /imports
|    import java.io.*
|    import java.math.*
|    import java.net.*
|    import java.nio.file.*
|    import java.util.*
|    import java.util.concurrent.*
|    import java.util.function.*
|    import java.util.prefs.*
|    import java.util.regex.*
|    import java.util.stream.*

다시 시작하고 싶을 때

jshell> import java.util.Scanner

jshell> ZonedDateTime
0: Do nothing
1: import: java.time.ZonedDateTime
Choice:
Imported: java.time.ZonedDateTime

jshell> ZonedDateTime now = ZonedDateTime.now()
now ==> 2018-12-21T16:14:20.037591Z[Etc/UTC]

보충하다

jshell> var lsit = List.
class     copyOf(   of(

줄 바꿈

jshell> var list = List.of("hoge","fuga","piyo")
list ==> [hoge, fuga, piyo]

jshell> var result = list.stream().filter(word -> word.startsWith("h"))
result ==> java.util.stream.ReferencePipeline$2@31610302

jshell> var result = list.stream().filter(word -> word.startsWith("h")
   ...>  ).collect(Collectors.toList())
result ==> [hoge]

jshell> /exit
|  Goodbye

/help

감상

총결산

참고 자료