yagdao-0.3.1 JPA guide
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This document introduces YAGDAO, a lightweight Java ORM framework that uses JPA and Hibernate. It provides annotation-based CRUD and custom data access methods without static code generation. YAGDAO supports Spring dependency injection and includes features like generic DAOs, query builders, pagination, and object fetching. The framework aims to reduce boilerplate code and dependency while enabling custom data access layers.
yagdao-0.3.1 JPA guide
- 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