File	Doc	Category	Size	Date	Package
EntityManager.java	API Doc	Glassfish v2 API	13129	Fri May 04 22:34:06 BST 2007	javax.persistence

EntityManager

Fields Summary

Constructors Summary

Methods Summary
public void	clear() Clear the persistence context, causing all managed entities to become detached. Changes made to entities that have not been flushed to the database will not be persisted. throws IllegalStateException if this EntityManager has been closed.
public void	close() Close an application-managed EntityManager. After the close method has been invoked, all methods on the EntityManager instance and any Query objects obtained from it will throw the IllegalStateException except for getTransaction and isOpen (which will return false). If this method is called when the EntityManager is associated with an active transaction, the persistence context remains managed until the transaction completes. throws IllegalStateException if the EntityManager is container-managed or has been already closed..
public boolean	contains(java.lang.Object entity) Check if the instance belongs to the current persistence context. param entity return true if the instance belongs to the current persistence context. throws IllegalStateException if this EntityManager has been closed. throws IllegalArgumentException if not an entity
public javax.persistence.Query	createNamedQuery(java.lang.String name) Create an instance of Query for executing a named query (in the Java Persistence query language or in native SQL). param name the name of a query defined in metadata return the new query instance throws IllegalStateException if this EntityManager has been closed. throws IllegalArgumentException if a query has not been defined with the given name
public javax.persistence.Query	createNativeQuery(java.lang.String sqlString) Create an instance of Query for executing a native SQL statement, e.g., for update or delete. param sqlString a native SQL query string return the new query instance throws IllegalStateException if this EntityManager has been closed.
public javax.persistence.Query	createNativeQuery(java.lang.String sqlString, java.lang.Class resultClass) Create an instance of Query for executing a native SQL query. param sqlString a native SQL query string param resultClass the class of the resulting instance(s) return the new query instance throws IllegalStateException if this EntityManager has been closed.
public javax.persistence.Query	createNativeQuery(java.lang.String sqlString, java.lang.String resultSetMapping) Create an instance of Query for executing a native SQL query. param sqlString a native SQL query string param resultSetMapping the name of the result set mapping return the new query instance throws IllegalStateException if this EntityManager has been closed.
public javax.persistence.Query	createQuery(java.lang.String qlString) Create an instance of Query for executing a Java Persistence query language statement. param qlString a Java Persistence query language query string return the new query instance throws IllegalStateException if this EntityManager has been closed. throws IllegalArgumentException if query string is not valid
public T	find(java.lang.Class entityClass, java.lang.Object primaryKey) Find by primary key. param entityClass param primaryKey return the found entity instance or null if the entity does not exist throws IllegalStateException if this EntityManager has been closed. throws IllegalArgumentException if the first argument does not denote an entity type or the second argument is not a valid type for that entity's primary key
public void	flush() Synchronize the persistence context to the underlying database. throws IllegalStateException if this EntityManager has been closed. throws TransactionRequiredException if there is no transaction throws PersistenceException if the flush fails
public java.lang.Object	getDelegate() Return the underlying provider object for the EntityManager, if available. The result of this method is implementation specific. throws IllegalStateException if this EntityManager has been closed.
public javax.persistence.FlushModeType	getFlushMode() Get the flush mode that applies to all objects contained in the persistence context. return flush mode throws IllegalStateException if this EntityManager has been closed.
public T	getReference(java.lang.Class entityClass, java.lang.Object primaryKey) Get an instance, whose state may be lazily fetched. If the requested instance does not exist in the database, throws {@link EntityNotFoundException} when the instance state is first accessed. (The persistence provider runtime is permitted to throw {@link EntityNotFoundException} when {@link #getReference} is called.) The application should not expect that the instance state will be available upon detachment, unless it was accessed by the application while the entity manager was open. param entityClass param primaryKey return the found entity instance throws IllegalStateException if this EntityManager has been closed. throws IllegalArgumentException if the first argument does not denote an entity type or the second argument is not a valid type for that entity's primary key throws EntityNotFoundException if the entity state cannot be accessed
public javax.persistence.EntityTransaction	getTransaction() Returns the resource-level transaction object. The EntityTransaction instance may be used serially to begin and commit multiple transactions. return EntityTransaction instance throws IllegalStateException if invoked on a JTA EntityManager.
public boolean	isOpen() Determine whether the EntityManager is open. return true until the EntityManager has been closed.
public void	joinTransaction() Indicate to the EntityManager that a JTA transaction is active. This method should be called on a JTA application managed EntityManager that was created outside the scope of the active transaction to associate it with the current JTA transaction. throws IllegalStateException if this EntityManager has been closed. throws TransactionRequiredException if there is no transaction.
public void	lock(java.lang.Object entity, javax.persistence.LockModeType lockMode) Set the lock mode for an entity object contained in the persistence context. param entity param lockMode throws IllegalStateException if this EntityManager has been closed. throws PersistenceException if an unsupported lock call is made throws IllegalArgumentException if the instance is not an entity or is a detached entity throws TransactionRequiredException if there is no transaction
public T	merge(T entity) Merge the state of the given entity into the current persistence context. param entity return the instance that the state was merged to throws IllegalStateException if this EntityManager has been closed. throws IllegalArgumentException if instance is not an entity or is a removed entity throws TransactionRequiredException if invoked on a container-managed entity manager of type PersistenceContextType.TRANSACTION and there is no transaction.
public void	persist(java.lang.Object entity) Make an entity instance managed and persistent. param entity throws EntityExistsException if the entity already exists. (The EntityExistsException may be thrown when the persist operation is invoked, or the EntityExistsException or another PersistenceException may be thrown at flush or commit time.) throws IllegalStateException if this EntityManager has been closed. throws IllegalArgumentException if not an entity throws TransactionRequiredException if invoked on a container-managed entity manager of type PersistenceContextType.TRANSACTION and there is no transaction.
public void	refresh(java.lang.Object entity) Refresh the state of the instance from the database, overwriting changes made to the entity, if any. param entity throws IllegalStateException if this EntityManager has been closed. throws IllegalArgumentException if not an entity or entity is not managed throws TransactionRequiredException if invoked on a container-managed entity manager of type PersistenceContextType.TRANSACTION and there is no transaction. throws EntityNotFoundException if the entity no longer exists in the database.
public void	remove(java.lang.Object entity) Remove the entity instance. param entity throws IllegalStateException if this EntityManager has been closed. throws IllegalArgumentException if not an entity or if a detached entity throws TransactionRequiredException if invoked on a container-managed entity manager of type PersistenceContextType.TRANSACTION and there is no transaction.
public void	setFlushMode(javax.persistence.FlushModeType flushMode) Set the flush mode that applies to all objects contained in the persistence context. param flushMode throws IllegalStateException if this EntityManager has been closed.