I have this written in Typescript but I need to write it in Java as part of java practice but I need help interpreting it into Java. //How to create RolePermission through endpoints static async addPermissions(roleId: number, permissionIds: number[]){ return permissionIds.map(async (permissionId) => { return await RolePermission.findOrCreate({where: {roleId: roleId, permissionId: permissionId}}); }); }

So RolePermission does not allow Static methods so I cannot create a findOrCreate() method in this class. And the addPermissions in RolePermissionServiceImpl requires a static method and not non-static. I am really confused here. 

And can you help with the body for findOrCreate method. May be that will help understand a little more:
public static findOrCreate(Long roleId, Long permissionId){

}

I am getting an error: findOrCreate()
Cannot resolve method findOrCreate in RolePermission.

Also, when I try Option 3: The method cannot be reference if it is non-static. I'm not too familiar with it so do you suggest I make it static?

Below is my RolePermission Model:

@Entity
@Getter
@Setter
public class RolePermission {

@Id
@GeneratedValue(
strategy = GenerationType.SEQUENCE,
generator = "Id")
// @Column(name = "id", nullable = false)
private Long id;
//
@ManyToOne(fetch = FetchType.LAZY,
cascade = CascadeType.REMOVE)
// @ManyToOne
@JoinColumn(name = "roleId")
@JsonIgnore
Role role;


@ManyToOne(fetch = FetchType.LAZY,
cascade = CascadeType.REMOVE)
// @ManyToOne
@JoinColumn(name = "permissionId")
// @JoinColumn(name = "permissionId", referencedColumnName = "permission",
// insertable = false,updatable = false)
@LazyToOne(LazyToOneOption.NO_PROXY)
@JsonIgnore
Permission permission;

@CreatedDate
@CreationTimestamp
@DateTimeFormat(iso = DateTimeFormat.ISO.DATE_TIME)
LocalDateTime createdAt;

@LastModifiedDate
@UpdateTimestamp
@DateTimeFormat(iso = DateTimeFormat.ISO.DATE_TIME)
LocalDateTime updatedAt;

}