SessionSynchronization (Java EE 5 SDK)

Java

Java EE 5 SDK

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javax.ejb Interface SessionSynchronization


public interface SessionSynchronization

The SessionSynchronization interface allows a session Bean instance to be notified by its container of transaction boundaries.

An session Bean class is not required to implement this interface. A session Bean class should implement this interface only if it wishes to synchronize its state with the transactions.


方法摘要
 void afterBegin()
          The afterBegin method notifies a session Bean instance that a new transaction has started, and that the subsequent business methods on the instance will be invoked in the context of the transaction.
 void afterCompletion(boolean committed)
          The afterCompletion method notifies a session Bean instance that a transaction commit protocol has completed, and tells the instance whether the transaction has been committed or rolled back.
 void beforeCompletion()
          The beforeCompletion method notifies a session Bean instance that a transaction is about to be committed.
 

方法详细信息

afterBegin

void afterBegin()
                throws EJBException,
                       RemoteException
The afterBegin method notifies a session Bean instance that a new transaction has started, and that the subsequent business methods on the instance will be invoked in the context of the transaction.

The instance can use this method, for example, to read data from a database and cache the data in the instance fields.

This method executes in the proper transaction context.

抛出异常:
EJBException - Thrown by the method to indicate a failure caused by a system-level error.
RemoteException - This exception is defined in the method signature to provide backward compatibility for enterprise beans written for the EJB 1.0 specification. Enterprise beans written for the EJB 1.1 and higher specifications should throw the javax.ejb.EJBException instead of this exception. Enterprise beans written for the EJB 2.0 and higher specifications must not throw the java.rmi.RemoteException.

beforeCompletion

void beforeCompletion()
                      throws EJBException,
                             RemoteException
The beforeCompletion method notifies a session Bean instance that a transaction is about to be committed. The instance can use this method, for example, to write any cached data to a database.

This method executes in the proper transaction context.

Note: The instance may still cause the container to rollback the transaction by invoking the setRollbackOnly() method on the instance context, or by throwing an exception.

抛出异常:
EJBException - Thrown by the method to indicate a failure caused by a system-level error.
RemoteException - This exception is defined in the method signature to provide backward compatibility for enterprise beans written for the EJB 1.0 specification. Enterprise beans written for the EJB 1.1 and higher specification should throw the javax.ejb.EJBException instead of this exception. Enterprise beans written for the EJB 2.0 and higher specifications must not throw the java.rmi.RemoteException.

afterCompletion

void afterCompletion(boolean committed)
                     throws EJBException,
                            RemoteException
The afterCompletion method notifies a session Bean instance that a transaction commit protocol has completed, and tells the instance whether the transaction has been committed or rolled back.

This method executes with no transaction context.

This method executes with no transaction context.

参数:
committed - True if the transaction has been committed, false if is has been rolled back.
抛出异常:
EJBException - Thrown by the method to indicate a failure caused by a system-level error.
RemoteException - This exception is defined in the method signature to provide backward compatibility for enterprise beans written for the EJB 1.0 specification. Enterprise beans written for the EJB 1.1 and higher specification should throw the javax.ejb.EJBException instead of this exception. Enterprise beans written for the EJB 2.0 and higher specifications must not throw the java.rmi.RemoteException.

Java EE 5 SDK

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