com.beasys.commerce.util
Class JDBCSequencer

java.lang.Object
  |
  +--com.beasys.commerce.util.JDBCSequencer

All Implemented Interfaces:

Sequencer

public class JDBCSequencer

extends java.lang.Object

implements Sequencer

Field Summary

static long	DEFAULT_CACHE_SIZE
static java.lang.String	DEFAULT_SEQUENCE_NAME
static java.lang.String	DEFAULT_SEQUENCER_NAME
static long	DEFAULT_STEP_SIZE
static java.lang.String	SEQUENCE_NAME_IDENTIFIER
static java.lang.String	SEQUENCE_VALUE_IDENTIFIER

Constructor Summary

JDBCSequencer()
Default constructor.

JDBCSequencer(java.lang.String sequencerName, java.lang.String sequenceName)
Creates a new JDBCSequencer with the supplied sequencer name and managed sequence name.

JDBCSequencer(java.lang.String sequencerName, java.lang.String sequenceName, long cacheSize)
Creates a new JDBCSequencer with the supplied sequencer name, managed sequence name, and cache size.

JDBCSequencer(java.lang.String sequencerName, java.lang.String sequenceName, long cacheSize, long stepSize)
Creates a new JDBCSequencer with the supplied sequencer name, managed sequence name, cache size, and step size.

Method Summary

protected void	allocateSequenceBlock(java.sql.Connection databaseConnection) Allocates a new block of sequence numbers from the database using the supplied database connection.
protected void	cleanUpResources() Closes any open DB resources.
protected static boolean	commitTransaction(java.sql.Connection databaseConnection, boolean transactionStarted) Commits the transaction associated with the supplied database connection if a transaction was previously started.
long	getCacheSize() Returns the cache size.
long	getCurrent(java.sql.Connection databaseConnection) Gets the current sequence number associated with this sequencer.
long	getIncrementAmount() Deprecated. Replaced by getCacheSize
long	getNext(java.sql.Connection databaseConnection) Gets the next sequence number using the supplied database connection.
java.lang.String	getSequenceName() Returns the name of the sequence that is managed by this sequencer.
java.lang.String	getSequencerName() Returns the name of this sequencer.
long	getStepSize() Returns the step size.
protected static boolean	rollbackTransaction(java.sql.Connection databaseConnection, boolean transactionStarted) Forces a rollback of the transaction associated with the supplied database connection if a transaction was previously started.
void	setCacheSize(long cacheSize) Sets the cache size.
void	setIncrementAmount(long incrementAmount) Deprecated. Replaced by setCacheSize
void	setSequenceName(java.lang.String sequenceName) Sets the name of the sequence that is managed by this sequencer.
void	setSequencerName(java.lang.String sequencerName) Sets the name of this sequencer.
void	setStepSize(long stepSize) Sets the step size.
protected static boolean	startTransaction(java.sql.Connection databaseConnection) Starts a transaction using the supplied database connection if the connection is not already assoicated with a transaction.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_CACHE_SIZE

public static final long DEFAULT_CACHE_SIZE

DEFAULT_STEP_SIZE

public static final long DEFAULT_STEP_SIZE

DEFAULT_SEQUENCER_NAME

public static final java.lang.String DEFAULT_SEQUENCER_NAME

DEFAULT_SEQUENCE_NAME

public static final java.lang.String DEFAULT_SEQUENCE_NAME

SEQUENCE_NAME_IDENTIFIER

public static final java.lang.String SEQUENCE_NAME_IDENTIFIER

SEQUENCE_VALUE_IDENTIFIER

public static final java.lang.String SEQUENCE_VALUE_IDENTIFIER

Constructor Detail

JDBCSequencer

public JDBCSequencer()

Default constructor.

JDBCSequencer

public JDBCSequencer(java.lang.String sequencerName,
                     java.lang.String sequenceName)

Creates a new JDBCSequencer with the supplied sequencer name and managed sequence name.

Parameters:

sequencerName - The name of the new sequencer.

sequenceName - The name of the managed sequence.

JDBCSequencer

public JDBCSequencer(java.lang.String sequencerName,
                     java.lang.String sequenceName,
                     long cacheSize)

Creates a new JDBCSequencer with the supplied sequencer name, managed sequence name, and cache size.

Parameters:

sequencerName - The name of the new sequencer.

sequenceName - The name of the managed sequence.

cacheSize - The cache size.

JDBCSequencer

public JDBCSequencer(java.lang.String sequencerName,
                     java.lang.String sequenceName,
                     long cacheSize,
                     long stepSize)

Creates a new JDBCSequencer with the supplied sequencer name, managed sequence name, cache size, and step size.

Parameters:

sequencerName - The name of the new sequencer.

sequenceName - The name of the managed sequence.

cacheSize - The cache size.

Method Detail

getNext

public long getNext(java.sql.Connection databaseConnection)
             throws java.sql.SQLException

Gets the next sequence number using the supplied database connection. The database connection will not be automatically closed upon method return. This class is thread safe.

Specified by:

getNext in interface Sequencer

Parameters:

databaseConnection - The database connection used to generate the next sequence number.

Throws:

SQLException - on error.

getCurrent

public long getCurrent(java.sql.Connection databaseConnection)
                throws java.sql.SQLException

Gets the current sequence number associated with this sequencer.

Specified by:

getCurrent in interface Sequencer

Parameters:

databaseConnection - The database connection used to generate the next sequence number.

Throws:

SQLException - on error.

startTransaction

protected static boolean startTransaction(java.sql.Connection databaseConnection)
                                   throws java.sql.SQLException

Starts a transaction using the supplied database connection if the connection is not already assoicated with a transaction.

Parameters:

databaseConnection - The database connection

Returns:

true if a transaction was started, false otherwise

Throws:

SQLException - on error.

rollbackTransaction

protected static boolean rollbackTransaction(java.sql.Connection databaseConnection,
                                             boolean transactionStarted)
                                      throws java.sql.SQLException

Forces a rollback of the transaction associated with the supplied database connection if a transaction was previously started.

Parameters:

databaseConnection - The database connection

transactionStarted - Return value from a call to startTransaction

Returns:

true if a rollback was performed, false otherwise

Throws:

SQLException - on error.

commitTransaction

protected static boolean commitTransaction(java.sql.Connection databaseConnection,
                                           boolean transactionStarted)
                                    throws java.sql.SQLException

Commits the transaction associated with the supplied database connection if a transaction was previously started.

Parameters:

databaseConnection - The database connection

transactionStarted - Return value from a call to startTransaction

Returns:

true if the transaction was committed, false otherwise

Throws:

SQLException - on error.

allocateSequenceBlock

protected final void allocateSequenceBlock(java.sql.Connection databaseConnection)
                                    throws java.sql.SQLException

Allocates a new block of sequence numbers from the database using the supplied database connection. If a transaction is not currently associated with the connection, one will be started and used for allocating a sequence block. This function uses a SELECT ... FOR UPDATE query to lock the sequencer row.

Parameters:

databaseConnection - The database connection used to generate the next sequence number.

Throws:

SQLException - on error.

cleanUpResources

protected final void cleanUpResources()

Closes any open DB resources.

getIncrementAmount

public long getIncrementAmount()

Deprecated. Replaced by getCacheSize

Returns the increment amount. The increment amount defines how often the sequencer will allocate a block of unique sequence numbers from the database. When the sequencer exhausts its supplied of allocated numbers, it will allocate a new sequence of numbers from the database.

Specified by:

getIncrementAmount in interface Sequencer

Returns:

The increment amount.

See Also:

getCacheSize()

setIncrementAmount

public void setIncrementAmount(long incrementAmount)

Deprecated. Replaced by setCacheSize

Sets the increment amount. The increment amount defines how often the sequencer will allocate a block of unique sequence numbers from the database. When the sequencer exhausts its supplied of allocated numbers, it will allocate a new sequence of numbers from the database.

Specified by:

setIncrementAmount in interface Sequencer

Parameters:

incrementAmount - The increment amount.

See Also:

setCacheSize(long)

getCacheSize

public long getCacheSize()

Returns the cache size. The cache size defines how often the sequencer will allocate a block of unique sequence numbers from the database. When the sequencer exhausts its supplied of allocated numbers, it will allocate a new sequence of numbers from the database.

Specified by:

getCacheSize in interface Sequencer

Returns:

The cache size.

setCacheSize

public void setCacheSize(long cacheSize)

Sets the cache size. The cache size defines how often the sequencer will allocate a block of unique sequence numbers from the database. When the sequencer exhausts its supplied of allocated numbers, it will allocate a new sequence of numbers from the database.

Specified by:

setCacheSize in interface Sequencer

Parameters:

cacheSize - The cache size.

getStepSize

public long getStepSize()

Returns the step size. The step size determines the difference between the values returned from successive calls to getNext().

Specified by:

getStepSize in interface Sequencer

Returns:

The step size.

setStepSize

public void setStepSize(long stepSize)

Sets the step size. The step size determines the difference between the values returned from successive calls to getNext().

Specified by:

setStepSize in interface Sequencer

Parameters:

stepSize - The step size.

getSequencerName

public java.lang.String getSequencerName()

Returns the name of this sequencer.

Specified by:

getSequencerName in interface Sequencer

Returns:

The sequencer name.

setSequencerName

public void setSequencerName(java.lang.String sequencerName)

Sets the name of this sequencer.

Specified by:

setSequencerName in interface Sequencer

Parameters:

sequencerName - The new sequencer name.

getSequenceName

public java.lang.String getSequenceName()

Returns the name of the sequence that is managed by this sequencer.

Specified by:

getSequenceName in interface Sequencer

Returns:

The sequence name.

setSequenceName

public void setSequenceName(java.lang.String sequenceName)

Sets the name of the sequence that is managed by this sequencer.

Specified by:

setSequenceName in interface Sequencer

Parameters:

sequenceName - The new sequence name.