net.sf.spif
Class StoreAccumulator

java.lang.Object
  |
  +--net.sf.spif.StoreChain
        |
        +--net.sf.spif.StoreAccumulator

public class StoreAccumulator

extends StoreChain

A store accumulator can accumulate several puts and removes, and forget them, or send them further down the chain at some later time. Use this too create long transactions without having to make the business code using the store transaction-aware.

This class is not thread safe.

Version:

$Id: StoreAccumulator.java,v 1.2 2003/02/05 22:15:44 bratseth Exp $

Author:

Jon S Bratseth

Field Summary

Fields inherited from class net.sf.spif.StoreChain

chained

Constructor Summary

StoreAccumulator()

Method Summary

void	begin() Starts a transaction.
void	clear() Clears all puts and gets and sets this to be not in a transaction
void	commit() Commits all accumulated changes (puts and removes) to the downstream store chain.
java.lang.Object	get(Id id, boolean writable) Returns an object.
boolean	inTransaction() Returns whether we are in a transaction
Id	put(Id id, java.lang.Object object) Accumulates the put in this class until commit if a transaction has started.
boolean	remove(Id id) Accumulates the remove in this class until commit if a transaction has started.
void	rollback() Rolls back all changes if we are in a transaction.

Methods inherited from class net.sf.spif.StoreChain

equals, getChained, getChained, getChained, hashCode, setChained

Methods inherited from class java.lang.Object

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

Constructor Detail

StoreAccumulator

public StoreAccumulator()

Method Detail

get

public java.lang.Object get(Id id,
                            boolean writable)

Returns an object. Changes which are not yet committed are reflected in what it returned, writable or not.

Overrides:

get in class StoreChain

Parameters:

id - the id of the object to return

Returns:

the object, or null if the object could not be retrieved or if the input id was null

put

public Id put(Id id,
              java.lang.Object object)

Accumulates the put in this class until commit if a transaction has started. Passes it on if not.

Overrides:

put in class StoreChain

Parameters:

id - the id of the object to put. May be null

object - the object to put. May be null

Returns:

the id if we are not in a transaction, null if we are

remove

public boolean remove(Id id)

Accumulates the remove in this class until commit if a transaction has started. Passes it on if not.

Overrides:

remove in class StoreChain

Parameters:

id - the id of the object to remove

Returns:

true if the object did not exists

clear

public void clear()

Clears all puts and gets and sets this to be not in a transaction

Overrides:

clear in class StoreChain

rollback

public void rollback()

Rolls back all changes if we are in a transaction. Does nothing if we are not

begin

public void begin()

Starts a transaction. Does nothing if we are allready in one.

commit

public void commit()

Commits all accumulated changes (puts and removes) to the downstream store chain. Does nothing if we are not in a transaction.

inTransaction

public boolean inTransaction()

Returns whether we are in a transaction