Programming 73

[20212115 TIL] [Spring] Java - Spring ํ”„๋กœ์ ํŠธ 1์ผ์ฐจ

ํšŒ์‚ฌ์—์„œ ์‹œ์Šคํ…œ ์œ ์ง€๋ณด์ˆ˜ ์œ„์ฃผ๋กœ ํ•˜๋‹ค๋ณด๋‹ˆ๊นŒ ๊ฐœ๋ฐœ์ž๋กœ์„œ์˜ ์‹ค๋ ฅ์ด ์ž˜ ๋Š˜์ง€ ์•Š๋Š” ๊ฒƒ ๊ฐ™์•„์„œ ๋”ฐ๋กœ ์ž๋ฐ” ํ”„๋กœ์ ํŠธ๋ฅผ ๊ธฐํšํ•ด๋ณด์•˜๋‹ค. ์ผ๋‹จ ์ต์ˆ™ํ•œ JAVA, SPRING, ORACLE์„ ์‚ฌ์šฉํ•˜๋ฉด์„œ REST API๋„ ์จ๋ณด๋Š”๊ฒŒ ๋ชฉํ‘œ๋‹ค! 1. ์Šคํ”„๋ง ๊ธฐ๋ณธ ์„ค์ • https://kuzuro.blogspot.com/2019/08/1.html ์Šคํ”„๋ง ๊ฒŒ์‹œํŒ ๋งŒ๋“ค๊ธฐ #1. ์Šคํ”„๋ง ๊ธฐ๋ณธ ์„ค์ • ๊ฐœ๋ฐœ์ž, ์›น๊ฐœ๋ฐœ, PC์•ฑ๊ฐœ๋ฐœ, Java, C#, HTML/CSS, JavaScript, Spring, ASP, .NET kuzuro.blogspot.com ์ด๊ฑฐ ๋”ฐ๋ผํ•˜๋‹ค๊ฐ€ ์„œ๋ฒ„ ์—ฐ๋™ ๊ณผ์ •์—์„œ unknown version of tomcat was specified ๋ฌธ๊ตฌ๊ฐ€ ์ž๊พธ ๋– ์„œ... ํ†ฐ์บฃ ๊น”์•˜๋˜ ๊ฒƒ์„ ๊ทธ๋ƒฅ ์ง€์›Œ๋ฒ„๋ฆฐ ํ›„์— https://kuz..

Programming/Java 2021.12.15

[20211214 TIL] [์‹œํ์–ด์ฝ”๋”ฉ] ๋„(Null)ํฌ์ธํ„ฐ ์—ญ์ฐธ์กฐ (NULL Pointer Dereference)

์ •๋ณด์ฒ˜๋ฆฌ๊ธฐ์‚ฌ์—์„œ ์ฐธ ์™ธ์šฐ๊ธฐ ํž˜๋“ค์—ˆ๋˜, ์‹œํ์–ด์ฝ”๋”ฉ. ์‹ค๋ฌด์—์„œ ๋ณด๋‹ˆ๊นŒ ์ •๋ง ๋ฐ˜๊ฐ€์› ๋‹ค. ์‹œํ์–ด์ฝ”๋”ฉ์ด ์ด๋ ‡๊ฒŒ ์“ฐ์ด๋Š” ๊ตฌ๋‚˜ ์‹ถ์—ˆ๋‹ค. ๋ฌผ๋ก  ์ฒ˜์Œ๋ถ€ํ„ฐ ์‹œํ์–ด์ฝ”๋”ฉ ๊ฐ€์ด๋“œ์— ๋งž๊ฒŒ ์ฝ”๋”ฉํ•˜๋ฉด ์ข‹๊ฒ ์ง€๋งŒ, ๊ทธ๋ ‡์ง€ ๋ชปํ•œ ๊ฒฝ์šฐ๋“ค๋„ ์žˆ๋‹ค. ํ˜„ํšŒ์‚ฌ์—์„œ๋Š” ํŒจํ‚ค์ง€ ๊ฐœ๋ฐœ์ด ๋ชจ๋‘ ๋๋‚œ ํ›„์— ์‹œํ์–ด์ฝ”๋”ฉ์„ ํ•ด์ฃผ๋Š” ํšŒ์‚ฌ์—์„œ ์‹œํ์–ด์ฝ”๋”ฉ ์ ๊ฒ€์„ ๋ฐ›์•˜๋‹ค. ์—…์ฒด์ธก์—์„œ ๋ณด๊ณ ์„œ๊ฐ€ ๋‚ ๋ผ์™”๊ณ  ๊ทธ ๋ณด๊ณ ์„œ์—๋Š” ์‹œํ์–ด์ฝ”๋”ฉ์„ ์ง€ํ‚ค์ง€ ๋ชปํ•œ ๋ณด์•ˆ์•ฝ์ ๋“ค์— ๋Œ€ํ•œ ๋‚ด์šฉ์ด ์ ํ˜€์žˆ์—ˆ๋‹ค. ๋‚˜๋„ ๊ทธ ๋ณด์•ˆ์•ฝ์ ์„ ์ˆ˜์ •ํ•˜๋Š” ์—ญํ• ์„ ๋งก์•˜๋‹ค. ๋‚ด๊ฐ€ ๋งก์€ ๋ถ€๋ถ„์€ ๋„ ํฌ์ธํ„ฐ ์—ญ ์ฐธ์กฐ์— ๋Œ€ํ•œ ๋ณด์•ˆ์•ฝ์ ์ด์—ˆ๋‹ค. Q. ๋„(Null)ํฌ์ธํ„ฐ ์—ญ์ฐธ์กฐ๋ž€? '์ผ๋ฐ˜์ ์œผ๋กœ ๊ทธ ๊ฐ์ฒด๊ฐ€ Null์ด ๋  ์ˆ˜ ์—†๋‹ค'๋ผ๊ณ  ํ•˜๋Š” ๊ฐ€์ •์„ ์œ„๋ฐ˜ํ–ˆ์„ ๋•Œ ๋ฐœ์ƒํ•œ๋‹ค. ๊ณต๊ฒฉ์ž๊ฐ€ ์˜๋„์ ์œผ๋กœ Null ํฌ์ธํ„ฐ ์—ญ์ฐธ์กฐ๋ฅผ ์‹คํ–‰ํ•˜๋Š” ๊ฒฝ์šฐ, ๊ทธ ๊ฒฐ๊ณผ..

Programming/Java 2021.12.14

[Javascript] ์ž๋ฐ”์Šคํฌ๋ฆฝํŠธ ์˜ค๋Š˜๋‚ ์งœ ์š”์ผ๊ตฌํ•˜๊ธฐ, ํŠน์ •๋‚ ์งœ ์š”์ผ๊ตฌํ•˜๊ธฐ

1. ์˜ค๋Š˜๋‚ ์งœ ์š”์ผ ๊ตฌํ•˜๊ธฐ var week = ['์ผ', '์›”', 'ํ™”', '์ˆ˜', '๋ชฉ', '๊ธˆ', 'ํ† ']; var date = new Date().getDay(); var day = week[date]; return day; var date = new Date(); return dateํ•˜๋ฉด, ์ด๋ ‡๊ฒŒ ๋‚˜์˜จ๋‹ค. var date = new Date().getDay(); retrun date ํ•˜๋ฉด, 4๊ฐ€ ๋‚˜์˜จ๋‹ค. week[4]๋Š” ๋ชฉ! 2. ํŠน์ •๋‚ ์งœ ์š”์ผ๊ตฌํ•˜๊ธฐ var week = ['์ผ', '์›”', 'ํ™”', '์ˆ˜', '๋ชฉ', '๊ธˆ', 'ํ† ']; var date = new Date('2021/09/03').getDay(); var day = week[date]; return day; * new Date() ๋‚ ..