@Temporal Annotation in JPA

1. Temporal annotation

The java.util or java.time properties need to explicitly mark the SQL type correlation with the @Temporal annotation prior to Java 8. In JPA or Hibernate, @Temporal should only be set on a java.util.Date or java.util.Calendar property.

• @Temporal  annotation must be specified for persistent fields or properties of type java.util.Date and java.util.Calendar.
• In JPA, @Temporal annotation solves the one of the major issue of converting the date and time values from Java object to compatible database type and retrieving back to the application.
• The mapping between the Java 8 Date/Time classes and the SQL types is implicit, there is not need to specify the @Temporal annotation.

• JPA supports:
  1. @Temporal(TemporalType.TIMESTAMP)
  2. @Temporal(TemporalType.DATE)
  3. @Temporal(TemporalType.TIME)
• These types are equivalent of  
  1. java.sql.Timestamp
  2. java.sql.Date
  3. java.sql.Time

Technologies Used in following example :

• JPA 2.1
• Hibernate 5.2.6
• MySql 8.0
• Maven 3
• Spring Tool Suite (STS) 3.9.8
• Java 1.8

2. @Temporal annotation mapping example

@Entity(name="USER")
public class User {
    
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO, generator = "native")
    @GenericGenerator(name = "native", strategy = "native")
    @Column(name = "ID")
    private Long id;
    
    @Column(name="USER_NAME")
    private String userName;
    
    @Column(name="PASSWORD")
    private String password;
    
    @Temporal(value=TemporalType.TIMESTAMP)
    @Column(name="CREATED_TIME")
    private Date creationTime;
    
    @Temporal(value=TemporalType.TIMESTAMP)
    @Column(name="UPDATED_TIME")
    private Date updatedTime;
    
    @Temporal(value=TemporalType.DATE)
    @Column(name="DOB")
    private Date dateofBirth;
    
    @Enumerated(value=EnumType.STRING)
    @Column(name="USER_TYPE")
    private UserType userType;

• From the above snippet line numbers 16,20,24 describes the mapping of Temporal type to the Entity.
• @Temporal annotation more useful to convert specific type either TimeStamp or Time or Date.

3.1 Test the mapping

public static void main( String[] args )
    {
        EntityManagerFactory emf = null;
        EntityManager entityManager = null;
        EntityTransaction transaction = null;
        
        try{
            emf = Persistence.createEntityManagerFactory("jbd-pu");
            entityManager = emf.createEntityManager();
            transaction = entityManager.getTransaction();
            transaction.begin();
            
            User user = new User();
            user.setUserName("mike");
            user.setPassword("password");
            // Setting Current Date
            user.setCreationTime(new Date());
            user.setDateofBirth(new Date());
            user.setUserType(UserType.EMPLOYEE);
    
            entityManager.persist(user);
            transaction.commit();
        }catch(Exception e){
            transaction.rollback();
        }finally{
            entityManager.close();
            emf.close();
        }
    }

Download Application – JPA-Temporal.zip (11 KB)

3.2. You might be interested in following articles

1. Transient annotation in JPA and hibernate
2. Hibernate Types

4. Conclusion

In this quick guide, we have learned about how to use @Temporal annotation in JPA or Hibernate applications.

5. References

1. Hibernate document