ADF-BC EO 介绍ppt课件

1、ADF-BC EO 介绍介绍资深技术顾问甲骨文 开发者计划ADF-BC Entities ObjectCharacteristics of Entity ObjectsEntity objects: Represent a row in a database table or other data source Handle database caching Contain attributes representing the database columns Encapsulate attribute-level and entity-level validation logic Can

2、contain custom business methodsUsing Entity Objects to Persist DataCustomersEOIdNameStatusEmailEntity objectAttributesDatabase tableStatus List(Gold Silver Platinum)Validation ruleID201NAMESteveSTATUSGoldEmail202MikeSilverCUSTOMERSCreating Entity Objects from Tables, Views, or SynonymsWhen you creat

3、e an entity object, JDeveloper: Interrogates the data dictionary for information about attribute Names, types, relationships based on primary/foreign key relationships, Infers primary key, or creates one from RowID Creates implicit validators for database constraints Creates the XML component defini

4、tion file (.xml) Creates optional Java files if selected, such as entity object class Impl.java Generates associations based on foreign keys, if applicable (FkAS.xml) these should be renamedModifying the Default Behavior of Entity Objects With declarative settings, you can: Define attribute control

5、hints Use alternate key entity constraints Refactor (rename or move) objects Create and publish events Validate user input (presented in a later lesson) Many other modifications are possible with coding, such as: Overriding base class methods Implementing calculation and recalculation of transient a

6、ttributesDefining Attribute Control Hints12Associations Define a relationship between EOs Facilitate access to data in related entity objects May be based on database constraints May be independent of database constraints Are used in defining validations and LOV metadata Consist of a source (master)

7、 and a destination (detail) entitySourceDestinationOrdersPersonsFkASAssociationPersonsEOOrdersEOCreating Associations Automatically created when creating 2nd EO with foreign keyCreating Associations Using the Create Association wizardAssociation Types Association Entities are related but not complet

8、ely dependent Either end of the association can exist without the other Either can be deleted without deleting the other Composition Destination entity is completely dependent on the source entity The source entity owns the destination entity No destination entity can be created without the owning e

9、ntity existing first The source entity cannot be deleted without deleting all its associated destination entitiesUsing Alternate Key Entity ConstraintsAlternate keys are: Used for efficient uniqueness checks Used for direct row lookups with findByKey() methods Different from primary keys or unique k

10、eysRefactoring ObjectsWith refactoring you can: Rename objects, such as associations and view links Move objects or packages to a different package Change all references throughout the applicationWorking Programatically with Entities and AssociationsFinding an Entity Object by Primary KeypublicStrin

11、gfindOrderID(longorderId)StringentityName=oracle.apps.str.model.entity.OrderEO;EntityDefImplorderDef=EntityDefImpl.findDefObject(entityName);KeyorderKey=newKey(newObjectorderId);EntityImplorder=orderDef.findByPrimaryKey(getDBTransaction(),orderKey);if(order!=null)return(String)order.getAttribute(“Sh

12、ipToName);elsereturnnull;1234public String getLocationId() return getDepartmentEO().getLocationId(); Traversing Associations:Source to Destination The destination entitys EntityImpl.java methods to get and set the source entity. For example, EmployeeEOImpl.java contains getDepartmentEO() and setDepa

13、rtmentEO(). You could add a method to EmployeeEO.java to get the Location ID of the department to which the employee belongs:getEmployeeEO()DepartmentEODepartmentEOToEmployeeEOEmployeeEOgetDepartmentEO()getLocationId()Updating or Removingan Existing Entity Rowpublic void updateEmpEmail(long empId, S

14、tring newEmail) EntityImpl emp = retrieveEmployeeById(empId); if (emp != null) emp.setAttribute(“Email,newEmail); try getDBTransaction().commit(); catch (JboException ex) getDBTransaction().rollback(); throw ex; 123Creating a New Entity Rowpublic long createProduct(String name, String description) S

15、tring entityName = “oracle.apps.str.model.entity.ProductEO; EntityDefImpl productDef = EntityDefImpl.findDefObject(entityName); EntityImpl newProduct = productDef.createInstance2(getDBTransaction(),null); newProduct.setAttribute(Name,name); newProduct.setAttribute(Description,description); try getDB

16、Transaction().commit(); catch (JboException ex) throw ex; DBSequence newIdAssigned = (DBSequence)newProduct.getAttribute(ProdId); return newIdAssigned.getSequenceNumber().longValue(); 12345Coding: The Supporting Java Classes EntityImpl The entity class Represents a row Provides getter and setter met

17、hods EntityDefImpl The entity definition class Represents the whole entity Can be used to modify the entity definition EntityCollImpl Represents the cached set of rows from the entity It is not necessary to modify or override methods in this classOverriding Base Class MethodsYou can override methods in the base classes for objects. For example, you can override methods in EntityImpl.java, such as: doDML() Use to log changes in another entity beforeCommit() Use to validate multiple instances of the same entity remove() Use to log a deletion in an entityOverri