yagdao-0.3.1 JPA guide http://www.altuure.com/projects/yagdao/

1. Yet Another DAO
JPA Guide
YAGDAO 0.3.1

2. yagdao
 http://www.altuure.com/projects/yagdao
 Mert Can Akkan
 mcakkan@yahoo.com
 http://www.altuure.com

3. overview
 Popular Java ORM layer
 JPA 2.0
 Hibernate
 Spring 3.0+ Support (optional)
 Lightweight
 No Implementation Framework
 No Static Code Generation
 Annotation Based
 GenericDAO/CRUD operations
 Custom operations

4. dependency-heaven
Lightweight framework with minimal dependency
GroupId ArtifactId Version Optional
cglib cglib 2.2 No
commons-logging commons-logging 1.0.2 No
org.antlr antlr-runtime 3.2 No
org.slf4j slf4j-log4j12 1.5.8 No
org.apache.geronimo.specs geronimo-jpa_2.0_spec 1.1 JPA
org.hibernate hibernate-core 3.5.1-Final hibernate
org.hibernate hibernate-entitymanager 3.5.1-Final hibernate
org.springframework spring-beans 3.0.4.RELEASE spring support
org.springframework spring-jdbc 3.0.4.RELEASE spring support
org.springframework spring-orm 3.0.4.RELEASE Spring support

5. maven dependecy
<dependencies>
<dependency>
<groupId>com.altuure</groupId>
<artifactId>com.altuure.yagdao</artifactId>
<version>0.3.1</version>
</dependency>
<dependencies>
<!-- repo.altuure.com-->
<repositories>
<repository>
<id>repo.altuure.com</id>
<name>repo.altuure.com</name>
<url>http://repo.altuure.com</url>
<layout>default</layout>
</repository>
</repositories>

6. my first yagdao
 easy implementation
public interface UserDAO extends
GenericDAO<User,Long>{
}

7. quickstart
 GenericHibernateDAOFactory
userDAO = (UserDAO)
GenericHibernateDAOFactory.createInstance(UserDAO.class,
sessionAccessor);
The GenericHibernateDAOFactory will create instance
of given DAO at the runtime

8. springframework support
 package scan feature
<yagdao:jpa id="DAOFactory1"
base-package="com.altuure.yagdao.blog.dao"
entity-manager-factory="entityManagerFactory"/>
 one by one definition
<yagdao:jpa
base-class="com.altuure.yagdao.blog.dao.UserDAO"
session-factory="mySessionFactory"/>

9. GenericDAO
 save(Object entity)
 update(Object entity)
 load(T id)
 loadLazy(T id)
 delete(Object object)
 delete(T id)
 vs….

10. custom methods
create & update
 Get rid of all setter and getter operations
public interface UserDAO extends GenericDAO<User,Long>{
@YMethod(type = YMethodType.SAVE)
User create(
@YParameter("username")String username,
@YParameter("password")String password,
@YParameter("email")String email);
@YMethod(type = YMethodType.UPDATE)
User updateRoles(long id,
@YParameter("roles")Set roles);
}

11. custom methods
query
 Embeded Query Support
@YMethod(
type = YMethodType.QUERY,
query="select u.username from User u where u.email=:email“
)
String findUsernameByEmailQuery(
@YParameter(value = "email")String email);
 Named Query Support
@YMethod(type = YMethodType.QUERY,queryName="findByEmail")
String findUsernameByEmailNamed(
@YParameter(value = "email")String email);

12. custom methods
execute
@YMethod(type = YMethodType.EXECUTE,
query="update User set password=:password")
int updateAllPasswords(String newPassword);
Tip:
All execute methods must return an integer

13. custom methods
append
 APPEND Method handler is a simple query builder
in which you can append query strings with not null
parameters
@YMethod(type = YMethodType.APPEND,
select = "pbyte,count(id)",
groupBy = "pbyte",
having = "count(id)>10")
List<SimpleBean> appendQuery(
@YParameter("pint>=?") int i);

14. custom methods
criteria &count(experimental)
 Criteria method handler is like append method
handler tries to build a query with not null values by
parsing query parameters.

15. custom methods
criteria
•Custom Paging and order is supported
•Selected field and fetch are supported
@YMethod(type = YMethodType.CRITERIA)
SearchResultList<SimpleBean>
criteria1(@YParameter(value = "pint>=") Integer
arg1);

16. custom methods
count
@YMethod(type = YMethodType.COUNT)
long count2(@YParameter("pint") Integer arg1,
@YParameter("pdate<=")Date endDate);
Returns only count query result of criteria method
To execute both see SearchResultList

17. smart parameters & return types
 YPage: enables order and paging
 criteria methods
 YLimit: enables only paging
 append method
 criteria methods
 SearchResultList: fetch total size of result list
public SearchResultList(List<T> result,
long totalCount, YPage paging) {
super(result);
this.totalCount = totalCount;
this.paging = paging;
}

18. paging
To add paging to any querying method is easy just
add YPage,YLimit as a method parameter
@YMethod(type = YMethodType.APPEND,orderBy = "id desc")
SearchResultList appendPage1(@YParameter("pbyte>=?")
byte arg1,YLimit limit);
PS: YLimit is valid in all while YPage is valid on only
Criteria Methods

19. prefetch result size
Defining ‘SearchResultList’ as a return type enables a
count queires for all methods
@YMethod(type = YMethodType.CRITERIA)
SearchResultList<SimpleBean> criteria1(@YParameter(value = "pint>=") Integer
arg1);

20. and more
 Object based and method based fetch support
@YMethod(type = YMethodType.CRITERIA)
@YFetch({ "product", "order", "order.customer" })
List<OrderItem> findByCustomerCityAndMaxPrice2(…);
 projection support at append methods

21. thanks 
For more please see sample application:
http://code.google.com/p/yagdao/downloads/list?q=label:Type-Sample
maven jetty:run
http://localhost:8080/blog