@Column is not the appropriate annotation. You don't want to store a whole User or Question in a column. You want to create an association between the entities. Start by renaming Questions to Question, since an instance represents a single question, and not several ones. Then create the association:
@Entity
@Table(name = "UserAnswer")
public class UserAnswer {
// this entity needs an ID:
@Id
@Column(name="useranswer_id")
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
@ManyToOne
@JoinColumn(name = "user_id")
private User user;
@ManyToOne
@JoinColumn(name = "question_id")
private Question question;
@Column(name = "response")
private String response;
//getter and setter
}
The Hibernate documentation explains that. Read it. And also read the javadoc of the annotations.