Beer.java

package guru.springframework.spring6restmvc.entities;

import lombok.*;
import org.hibernate.annotations.CreationTimestamp;
import org.hibernate.annotations.UpdateTimestamp;

import jakarta.persistence.*;
import java.math.BigDecimal;
import java.time.LocalDateTime;
import java.util.HashSet;
import java.util.Set;
import java.util.UUID;

@Getter
@Setter
@Builder
@NoArgsConstructor
@AllArgsConstructor
@Entity
public class Beer {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private UUID id;

    private String name;
    private String style;
    private String upc;
    private Integer quantityOnHand;
    private BigDecimal price;

    @CreationTimestamp
    private LocalDateTime createdDate;

    @UpdateTimestamp
    private LocalDateTime lastModifiedDate;

    @ManyToMany
    @JoinTable(name = "beer_category",
            joinColumns = @JoinColumn(name = "beer_id"),
            inverseJoinColumns = @JoinColumn(name = "category_id"))
    private Set<Category> categories = new HashSet<>();

    public void addCategory(Category category){
        this.categories.add(category);
        category.getBeers().add(this);
    }

    public void removeCategory(Category category){
        this.categories.remove(category);
        category.getBeers().remove(this);
    }
}