인프런 커뮤니티 질문&답변

@RequiredArgsConstructor
@RestControllerpublic 
class MemberController {

private final MemberRepository memberRepository; 

@GetMapping("/members/{id}")
public String findMember(@PathVariable("id") Long id) {
Member member = memberRepository.findById(id).get(); 
return member.getUsername(); 
}

public void init() {
memberRepository.save(new Member("userA")); 
}

2023-06-17T14:29:55.066+09:00 DEBUG 6856 --- [nio-8080-exec-1] org.hibernate.SQL :

select

m1_0.member_id,

m1_0.age,

m1_0.created_by,

m1_0.created_date,

m1_0.last_modified_by,

m1_0.last_modified_date,

m1_0.team_id,

m1_0.username

from

member m1_0

where

m1_0.member_id=?

2023-06-17T14:29:55.068+09:00 INFO 6856 --- [nio-8080-exec-1] p6spy : #1686979795068 | took 0ms | statement | connection 4| url jdbc:h2:tcp://localhost/~/datajpa

select m1_0.member_id,m1_0.age,m1_0.created_by,m1_0.created_date,m1_0.last_modified_by,m1_0.last_modified_date,m1_0.team_id,m1_0.username from member m1_0 where m1_0.member_id=?

select m1_0.member_id,m1_0.age,m1_0.created_by,m1_0.created_date,m1_0.last_modified_by,m1_0.last_modified_date,m1_0.team_id,m1_0.username from member m1_0 where m1_0.member_id=1;

2023-06-17T14:29:55.071+09:00 INFO 6856 --- [nio-8080-exec-1] p6spy : #1686979795071 | took 0ms | commit | connection 4| url jdbc:h2:tcp://localhost/~/datajpa

;

2023-06-17T14:29:55.074+09:00 ERROR 6856 --- [nio-8080-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed: java.util.NoSuchElementException: No value present] with root cause

java.util.NoSuchElementException: No value present

at java.base/java.util.Optional.get(Optional.java:143) ~[na:na]

at study.datajpa.constoller.MemberController.findMember(MemberController.java:18) ~[classes/:na]

at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]

at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) ~[na:na]

at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]

at java.base/java.lang.reflect.Method.invoke(Method.java:568) ~[na:na]

at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:207) ~[spring-web-6.0.9.jar:6.0.9]

at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:152) ~[spring-web-6.0.9.jar:6.0.9]

at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:118) ~[spring-webmvc-6.0.9.jar:6.0.9]

at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:884) ~[spring-webmvc-6.0.9.jar:6.0.9]

http://localhost:8080/members/1에 userA가 나와야 하는데 Whitelabel Error Page가 뜨고 위와 같은 오류가 나옵니다.