Spring AnnotationException - Illegal attempt to map a non collection as a @OneToMany, @ManyToMany or @CollectionOfElements

[에러 메시지] AnnotationException: Illegal attempt to map a non collection as a @OneToMany, @ManyToMany or @CollectionOfElements

해결 방법

• 에러나는 코드

@OneToMany(fetch = FetchType.LAZY)
@JoinColumn(name = "userId")
private UserEntity userId;

• UserEntity를 List로 고치기

@OneToMany(mappedBy = "music_like", fetch = FetchType.LAZY)
@JoinColumn(name = "userId")
private List<UserEntity> userId;