How to apply unique constraints using annotation

Question

@Column(name = \"userId\")
    @UniqueConstraint
    private Integer userId;

I am using these annotation for entering data into database table. i want

Answer 1

@Column(name = "userId",unique=true)

or if its an DB generated ID you can also do this

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