## org.jboss.ejb
Interface EntityPersistenceStore

All Superinterfaces:
  ContainerPlugin, Service

All Known Implementing Classes:
  CMPFilePersistenceManager, JAWSPersistenceManager

public interface EntityPersistenceStore
extends ContainerPlugin

This interface is implemented by any EntityBean persistence Store. These stores just deal with the persistence aspect of storing java objects They need not be aware of the EJB semantics. They act as delegatees for the CMPEntityPersistenceManager class.

Version:
  $Revision: 1.4 $
Author:
  Rickard Öberg (rickard.oberg@telkel.com), Marc Fleury, danch (Dan Christopherson)
See Also:
  `EntityPersistenceManager`

Method Summary
`void` `activateEntity(EntityEnterpriseContext instance)` This method is called when an entity shall be activated.
`java.lang.Object` `createEntity(java.lang.reflect.Method m, java.lang.Object[] args, EntityEnterpriseContext instance)` This method is called whenever an entity is to be created.
`FinderResults` `findEntities(java.lang.reflect.Method finderMethod, java.lang.Object[] args, EntityEnterpriseContext instance)` This method is called when collections of entities are to be found.
`java.lang.Object` `findEntity(java.lang.reflect.Method finderMethod, java.lang.Object[] args, EntityEnterpriseContext instance)` This method is called when single entities are to be found.
`void` `loadEntities(FinderResults keys)` This method is called whenever a set of entities should be preloaded from the underlying storage.
`void` `loadEntity(EntityEnterpriseContext instance)` This method is called whenever an entity shall be load from the underlying storage.
`void` `passivateEntity(EntityEnterpriseContext instance)` This method is called when an entity shall be passivate.
`void` `removeEntity(EntityEnterpriseContext instance)` This method is called when an entity shall be removed from the underlying storage.
`void` `storeEntity(EntityEnterpriseContext instance)` This method is called whenever an entity shall be stored to the underlying storage.

Methods inherited from interface org.jboss.ejb.ContainerPlugin
`setContainer`

Methods inherited from interface org.jboss.util.Service
`destroy, init, start, stop`

Method Detail

### createEntity

    public java.lang.Object createEntity(java.lang.reflect.Method m,
                                         java.lang.Object[] args,
                                         EntityEnterpriseContext instance)
                                  throws java.lang.Exception

  This method is called whenever an entity is to be created. The persistence manager is responsible for handling the results properly wrt the persistent store. The return is The primary key in case of CMP PM Null in case of BMP PM (but no store should exist)
  Parameters:
    `m` - the create method in the home interface that was called
    `args` - any create parameters
    `instance` - the instance being used for this create call
  Returns:
    Object, the primary key computed by CMP PM or null for BMP
  Throws:
    `java.lang.Exception` -

### findEntity

    public java.lang.Object findEntity(java.lang.reflect.Method finderMethod,
                                       java.lang.Object[] args,
                                       EntityEnterpriseContext instance)
                                throws java.lang.Exception

  This method is called when single entities are to be found. The persistence manager must find out whether the wanted instance is available in the persistence store, if so it returns the primary key of the object.
  Parameters:
    `finderMethod` - the find method in the home interface that was called
    `args` - any finder parameters
    `instance` - the instance to use for the finder call
  Returns:
    a primary key representing the found entity
  Throws:
    `java.rmi.RemoteException` - thrown if some system exception occurs
    `javax.ejb.FinderException` - thrown if some heuristic problem occurs

### findEntities

    public FinderResults findEntities(java.lang.reflect.Method finderMethod,
                                      java.lang.Object[] args,
                                      EntityEnterpriseContext instance)
                               throws java.lang.Exception

  This method is called when collections of entities are to be found. The persistence manager must find out whether the wanted instances are available in the persistence store, and if so it must return a collection of primaryKeys.
  Parameters:
    `finderMethod` - the find method in the home interface that was called
    `args` - any finder parameters
    `instance` - the instance to use for the finder call
  Returns:
    an primary key collection representing the found entities
  Throws:
    `java.rmi.RemoteException` - thrown if some system exception occurs
    `javax.ejb.FinderException` - thrown if some heuristic problem occurs

### activateEntity

    public void activateEntity(EntityEnterpriseContext instance)
                        throws java.rmi.RemoteException

  This method is called when an entity shall be activated. With the PersistenceManager factorization most EJB calls should not exists However this calls permits us to introduce optimizations in the persistence store. Particularly the context has a "PersistenceContext" that a PersistenceStore can use (JAWS does for smart updates) and this is as good a callback as any other to set it up.
  Parameters:
    `instance` - the instance to use for the activation
  Throws:
    `java.rmi.RemoteException` - thrown if some system exception occurs

### loadEntity

    public void loadEntity(EntityEnterpriseContext instance)
                    throws java.rmi.RemoteException

  This method is called whenever an entity shall be load from the underlying storage. The persistence manager must load the state from the underlying storage and then call ejbLoad on the supplied instance.
  Parameters:
    `instance` - the instance to synchronize
  Throws:
    `java.rmi.RemoteException` - thrown if some system exception occurs

### loadEntities

    public void loadEntities(FinderResults keys)
                      throws java.rmi.RemoteException

  This method is called whenever a set of entities should be preloaded from the underlying storage. The persistence store is allowed to make this a null operation
  Parameters:
    `instances` - the EntityEnterpriseContexts for the entities that must be loaded
    `keys` - a PagableKeyCollection previously returned from findEntities.

### storeEntity

    public void storeEntity(EntityEnterpriseContext instance)
                     throws java.rmi.RemoteException

  This method is called whenever an entity shall be stored to the underlying storage. The persistence manager must call ejbStore on the supplied instance and then store the state to the underlying storage.
  Parameters:
    `instance` - the instance to synchronize
  Throws:
    `java.rmi.RemoteException` - thrown if some system exception occurs

### passivateEntity

    public void passivateEntity(EntityEnterpriseContext instance)
                         throws java.rmi.RemoteException

  This method is called when an entity shall be passivate. The persistence manager must call the ejbPassivate method on the instance. See the activate discussion for the reason for exposing EJB callback calls to the store.
  Parameters:
    `instance` - the instance to passivate
  Throws:
    `java.rmi.RemoteException` - thrown if some system exception occurs

### removeEntity

    public void removeEntity(EntityEnterpriseContext instance)
                      throws java.rmi.RemoteException,
                             javax.ejb.RemoveException

  This method is called when an entity shall be removed from the underlying storage. The persistence manager must call ejbRemove on the instance and then remove its state from the underlying storage.
  Parameters:
    `instance` - the instance to remove
  Throws:
    `java.rmi.RemoteException` - thrown if some system exception occurs
    `javax.ejb.RemoveException` - thrown if the instance could not be removed

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