HashSet in mapRow for JDBC template - spring-boot

Question

I would like to make a select from one of my user table. In this table there is a field, which is a HashSet. This Set has "role" objects. I need a unique mapRow method for this operation, but I don't know how to to do it with the Set.
You can see my code below:
#Entity
#Getter
#Setter
#ToString
public class User {
#Id
#GeneratedValue(strategy= GenerationType.IDENTITY)
private Integer id;
private String name;
#Column( nullable=false )
private String password;
#Column( unique=true, nullable=false )
private String email;
private Boolean active;
#ManyToMany()
#JoinTable(name="role_user")
private Set<Role> roles;
}
public class UserMapper implements RowMapper<User> {
#Override
public User mapRow(ResultSet rs, int rowNum) throws SQLException {
User user = new User();
user.setId(rs.getInt("id"));
user.setName(rs.getString("name"));
user.setPassword(rs.getString("password"));
user.setEmail(rs.getString("email"));
user.setActive(rs.getBoolean("active"));
//user.setRoles();
return user;
}
}