@Entity
public class Employee {
@Id
@GeneratedValue
private long id;
private String name;
@ElementCollection
@CollectionTable(name = "EMP_TASKS", joinColumns = @JoinColumn(name = "EMP_ID"))
@MapKeyJoinColumn(name = "TASK_ID")
@Column(name = "TASK_DATE")
private Map<Task, Date> taskMap;
.............
}