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[Spring boot] NullPointException ์˜ค๋ฅ˜ ํ•ด๊ฒฐ ๋ณธ๋ฌธ

SpringBoot

[Spring boot] NullPointException ์˜ค๋ฅ˜ ํ•ด๊ฒฐ

sun_young 2023. 8. 11. 02:41

๐Ÿšจ Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.NullPointerException] with root cause ์›์ธ!

๊ณ„์† ์œ„์— ์‚ฌ์ง„์ฒ˜๋Ÿผ ๋ฉ”์‹œ์ง€๊ฐ€ ๋œจ๋ฉด์„œ NullPointException ์˜ค๋ฅ˜๊ฐ€ ๋œจ๋Š”๋ฐ ์˜คํƒˆ์ž๊ฐ€ ์žˆ๋‚˜ ์‹ถ์–ด์„œ ํ•˜๋‚˜ํ•˜๋‚˜ ๋‹ค ํ™•์ธํ–ˆ์ง€๋งŒ ๊ทธ๋ž˜๋„ ํ•ด๊ฒฐ์„ ๋ชปํ•˜๊ณ  ์žˆ์—ˆ๋Š”๋ฐ..

 

๊ตฌ๊ธ€๋งํ•ด๋ณด๋‹ˆ ๋‚˜๋ž‘ ๋˜‘๊ฐ™์€ ์˜ค๋ฅ˜๊ฐ€ ๊ณ„์† ๋œจ๋Š” ์‚ฌ๋žŒ์ด ์žˆ์—ˆ๊ณ  ํ•ด๋‹น ๊ฒŒ์‹œ๊ธ€์„ ์ฐธ๊ณ ํ•ด์„œ ์˜ค๋ฅ˜๋ฅผ ํ•ด๊ฒฐํ•  ์ˆ˜ ์žˆ์—ˆ๋‹คใ… ใ… 

 

์ผ๋‹จ ๊ฒฐ๋ก ์€ private final FreeCommentRepository freeCommentRepository; << ์ด๋•Œ final์„ ์ ์–ด์ฃผ์ง€ ์•Š์•„์„œ ์˜์กด์„ฑ ์ฃผ์ž… ๊ด€๋ จ ๋ฌธ์ œ๊ฐ€ ์žˆ๊ธฐ ๋•Œ๋ฌธ์— ์˜ค๋ฅ˜๊ฐ€ ๋ฐœ์ƒํ•œ ๊ฒƒ!

 

๋‚ด๊ฐ€ ๊ฐœ์ธ ํ”„๋กœ์ ํŠธ ๋ธ”๋กœ๊ทธ์— ์ •๋ฆฌํ•˜๋ฉด์„œ ์“ด ๊ธ€์— ์ ์€ ๊ฑด๋ฐ

 

@RequiredArgsConstructor : final์ด๋‚˜ @NonNull์ด ๋ถ™์€ ํ•„๋“œ์— ์ƒ์„ฑ์ž๋ฅผ ์ƒ์„ฑํ•ด ์ค€๋‹ค. ๋นˆ์— ์ƒ์„ฑ์ž๊ฐ€ 1๊ฐœ์ด๊ณ  ์ƒ์„ฑ์ž์˜ ํŒŒ๋ผ๋ฏธํ„ฐ ํƒ€์ž…์ด ๋นˆ์œผ๋กœ ๋“ฑ๋ก์ด ๊ฐ€๋Šฅํ•˜๋‹ค๋ฉด @Autowired ์–ด๋…ธํ…Œ์ด์…˜ ์—†์ด ์˜์กด์„ฑ ์ฃผ์ž…์ด ๊ฐ€๋Šฅํ•˜๋‹ค.

 

@RequiredArgsConstructor ์–ด๋…ธํ…Œ์ด์…˜์„ ์‚ฌ์šฉํ•˜๋ฉด์„œ final์„ ์ ์–ด์ฃผ์ง€ ์•Š์•„์„œ ์˜์กด์„ฑ ์ฃผ์ž…์ด ์ œ๋Œ€๋กœ ๋˜์ง€ ์•Š์€ ๊ฒƒ์ด๋‹คใ…  

 


๐Ÿ”Ž ํ•ด๊ฒฐ ๋ฐฉ์•ˆ

๊ทธ๋ƒฅ ์œ„์— ๋งํ•œ ๊ฒƒ์ฒ˜๋Ÿผ final๋งŒ ์ถ”๊ฐ€ํ•ด์ฃผ๋ฉด ๋œ๋‹ค ๐Ÿ˜…

 

๋Œ“๊ธ€ ๋“ฑ๋ก๊นŒ์ง€ ์„ฑ๊ณต!

 

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