This post was migrated from Tistory. You can find the original here. DTO/Lombok @Getter public class UserSignUpDto { ... private boolean admin = false; ... } For a boolean field, @...

This post was migrated from Tistory. You can find the original here. Filter This is Spring’s life cycle. Security Spring Security is also made up of a lot of filters. The purpose of Secu...

This post was migrated from Tistory. You can find the original here. ExceptionHandler @ExceptionHandler(IllegalArgumentException.class) public ResponseEntity<ExceptionResponseDto> ...

This post was migrated from Tistory. You can find the original here. RequestParam (1) @PostMapping("/test3") public String p2(@RequestParam PostRequestDto requestDto) { System.ou...

This post was migrated from Tistory. You can find the original here. combination static List<List<Integer>> combination(List<Integer> list, List<Integer> result, int ...

This post was migrated from Tistory. You can find the original here. You combine from, order by, and group by with commas. select * from A, B select course_id, week, count(c.likes) from checkin...

This post was migrated from Tistory. You can find the original here. concept IoC Inversion of Control public class A{ b = new B(); } In code like the above, A creates b directly itself. ...

This post was migrated from Tistory. You can find the original here. Wildcards Source Unlike arrays, generics don’t support covariance/contravariance. // covariance Object[] Co...

This post was migrated from Tistory. You can find the original here. List List<Integer> list = Arrays.asList(new Integer[] {1,2,3}); List<int[]> list2 = Arrays.asList(new int[]{1, 2,...

This post was migrated from Tistory. You can find the original here. Stream.of Stream<int[]> stream = Stream.of(new int[3]); Stream<char[]> stream1 = Stream.of(new char[3]); ...