With Parancoe (www.parancoe.org) You can define and use your DAOs without implementing them. This speeds up the development of your application and the satisfaction of the developers. This presentation was held at the JavaDay in Torino, the October 20, 2007.

1. Parancoe usare i DAO senza implementarli a cura di Lucio Benfante Creative Commons Attribution-NonCommercial-ShareAlike 2.5 License Roma 2007

3. Convention over Configuration DRY (Don't repeat yourself) Don't re-invent the wheel Guidelines

4. Fun for the developer Main Guideline

6. ...easier with a good IDE

7. The new application

8. What I'm able to use? (JUNIOR Programmer)

9. What I like to use? (SENIOR Developer)

10. What for the persistent layer? Class.forName( "com.mioDbms.mioDriver" ); Connection con=null; try { con = DriverManager.getConnection ( “ jdbc:...”, “user”, “pass”); ResultSet rs; PreparedStatement ps = conn.prepareStatement( " SELECT * FROM Person WHERE name=? ”); ps. setString (1, "Lucio Benfante"); rs = ps.executeQuery(); while ( rs.next() ) { rs.getString...ecc..ecc.... } rs.close(); ps.close(); stmt.close(); } catch (Exception e){ ... } finally { try { con. close (); } catch( Exception ignoreMe ) {} } JDBC ?

11. NOIA!

13. NOIA!

15. A “simple” persistent class @Entity() public class Person { private Long id; private String firstName; private String lastName; private Integer version; @Id @GeneratedValue(strategy = GenerationType.AUTO) public Long getId() { ... } public void setId(Long id) { ... } public String getFirstName() { ... } public void setFirstName(String firstName) { ... } public String getLastName() { ... } public void setLastName(String lastName) { ... } @version public Integer getVersion() { ... } public void setVersion() { ... } }

17. NOIA!

18. The Parancoe Way @Entity() public class Person extends EntityBase { private String firstName; private String lastName; public String getFirstName() { ... } public void setFirstName(String firstName) { ... } public String getLastName() { ... } public void setLastName(String lastName) { ... } } ...auto-discovered!

21. NOIA!

23. Common implementation public List<Person> findByLastName (String lastName) { Session session = sessionFactory.openSession(); Transaction tx = null; List<Person> result = null; try { tx = session.beginTransaction(); Query q = session.createQuery( &quot;from Person p where p.lastName = ?”+ “ order by p.lastName” ); q.setString(0, lastName); result = q.list(); tx.commit(); } catch (HibernateException he) { if (tx!=null) tx.rollback(); throw he; } finally { try {session.close();} catch(Exception ignore) {} } return result; }

25. Parancoe DAO @Dao(entity=Person.class) public interface PersonDao extends GenericDao<Person, Long> { List<Person> findByLastName(String lastName); } Auto-discovered Automatically available in the Spring context people = dao().getPersonDao().findByLastName(“Benfante”);

27. Complex queries @Dao(entity=Person.class) public interface PersonDao extends GenericDao<Person, Long> { ... List<Person> searchByPartialUncasedLastName( String partialLastName); ... } @Entity() @NamedQueries({ @NamedQuery( name=&quot;Person.searchByPartialUncasedLastName&quot; , query=&quot;from Person p”+ ” where lower(p.lastName) like lower(?)”+ ” order by p.lastName&quot;) }) public class Person extends EntityBase { ... }

28. Methods of the base DAO PK create(T newInstance); void createOrUpdate(T o); T read(PK id); void update(T transientObject); void delete(T persistentObject); List<T> findAll(); List<T> searchByCriteria(Criterion... criterion); List<T> searchByCriteria(DetachedCriteria criteria); List<T> searchByCriteria( DetachedCriteria criteria, int firstResult, int maxResults); int deleteAll(); long count();