I am using Spring, JPA, Java17, MySQL.
IDE: IntelliJ IDEA 2022.2.4
JDK: Amazon Coretto 17.0.6

I am getting an error "Expected 0 arguments but found 3". (image)

Here is my Article entity class code and I am using Lombok to remove boilerplate code. For some reason RequiredArgsConstructor annotation cannot be well managed in test class and I need to create actual constructor to be able to work on it.

@Entity
@Getter
@Setter
@RequiredArgsConstructor
@Table(name = "article", schema = "chitchat")
public class Article {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @Column(name = "title", nullable = false, length = 150)
    private String title;

    @OneToOne
    @JoinColumn(name = "category_id")
    private Category category;

    @Column(name = "comment_count", nullable = false)
    private int commentCount;

    @Column(name = "view_count", nullable = false)
    private int viewCount;

    @ToString.Exclude
    @OneToMany(mappedBy = "article", orphanRemoval = true)
    private Set<Tag> tags = new LinkedHashSet<>();

    @Column(name = "modification_date")
    private LocalDateTime modificationDate;

    @Column(name = "creation_date", nullable = false)
    private LocalDateTime creationDate;

    @Column(name = "content", nullable = false, length = 50000)
    private String content;

    @OneToOne(optional = false, orphanRemoval = true)
    @JoinColumn(name = "author_id", nullable = false)
    private User author;

    @Column(name = "published", nullable = false)
    private Boolean published = false;

    @OneToMany(mappedBy = "article")
    private Set<Comment> comments = new LinkedHashSet<>();
}

I tried using AllArgsConstructor and creating constructor by hand (works fine).

CodePudding user response：

As docs of @RequiredArgsConstructor suggests:

Generates a constructor with required arguments. Required arguments are final fields and fields with constraints such as @NonNull.

So, your class does not have fields that match those criteria

Whereas @AllArgsConstructor :

Generates an all-args constructor. An all-args constructor requires one argument for every field in the class.

So, everything works as expected.