header.jsp
<li><a href="**/member/logout**">로그아웃</a></li>
MemberController.java
@GetMapping("/member/logout")
public ResponseEntity<String> logout(HttpSession session) {
// 세션 초기화
session.invalidate();
HttpHeaders headers = new HttpHeaders();
headers.add("Content-Type", "text/html; charset=utf-8");
String str = Script.href("로그아웃 되었습니다", "/");
return new ResponseEntity<String>(str, headers, HttpStatus.OK);
}