com.hp.util.persistence.cassandra

Class DataStoreContext

java.lang.Object

com.hp.util.persistence.cassandra.DataStoreContext

public class DataStoreContext
extends Object

DataStoreContext provides the context for a given query operation. Each query needs to have an EntityManager object and a lock manager object to complete the operation.

This class acts as a container for these objects and are used in the DAO methods.

Author:

Nachiket Abhyankar

Constructor Summary

Constructors

Constructor and Description
DataStoreContext(EntityManager em) Constructor.

Method Summary

Methods

Modifier and Type	Method and Description
EntityManager	getContext() This method is used extensively in the DAO to retrieve the EntityManager object for a given query.
com.hp.util.persistence.cassandra.lockmgr.impl.AbstractLockMgr	getTransactionContext() This method is used extensively in the DAO to retrieve the LockManager object for a given query.
void	setTransactionContext(com.hp.util.persistence.cassandra.lockmgr.impl.AbstractLockMgr lockMgr) This method sets the Transaction context.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DataStoreContext

public DataStoreContext(EntityManager em)

Constructor. Called from the UnitOfWork. The EntityManager object is created in the UnitOfWork using the EntityManagerFactory and passed in as an argument. The LockManager defaults to a fake lock manager making the query non-transactional.

Parameters:

em - The EntityManager object instance.

Method Detail

getContext

public EntityManager getContext()

This method is used extensively in the DAO to retrieve the EntityManager object for a given query.

Returns:

The EntityManager object

setTransactionContext

public void setTransactionContext(com.hp.util.persistence.cassandra.lockmgr.impl.AbstractLockMgr lockMgr)

This method sets the Transaction context. If the query is transactional, then an appropriate implementation of the lock manager interface is used to provide locking mechanism. This method sets the object of the selected implementation in the context.

Parameters:

lockMgr - The LockManager implementation for a given query.

getTransactionContext

public com.hp.util.persistence.cassandra.lockmgr.impl.AbstractLockMgr getTransactionContext()

This method is used extensively in the DAO to retrieve the LockManager object for a given query.

Returns:

The LockManager object