org.firebirdsql.gds.ng

Class AbstractFbBlob

java.lang.Object

org.firebirdsql.gds.ng.AbstractFbBlob

All Implemented Interfaces:

java.lang.AutoCloseable, FbBlob, DatabaseListener, ExceptionListenable, TransactionListener

Direct Known Subclasses:

AbstractFbWireBlob, JnaBlob

public abstract class AbstractFbBlob
extends java.lang.Object
implements FbBlob, TransactionListener, DatabaseListener

Since:

3.0

Author:

Mark Rotteveel

Nested Class Summary

Nested classes/interfaces inherited from interface org.firebirdsql.gds.ng.FbBlob

FbBlob.SeekMode

Field Summary

Fields

Modifier and Type	Field and Description
protected ExceptionListenerDispatcher	exceptionListenerDispatcher

Fields inherited from interface org.firebirdsql.gds.ng.FbBlob

NO_BLOB_ID

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractFbBlob(FbDatabase database, FbTransaction transaction, BlobParameterBuffer blobParameterBuffer)

Method Summary

Modifier and Type	Method and Description
void	addExceptionListener(ExceptionListener listener) Adds an exception listener to this object.
void	cancel() Cancels an output blob (which means its contents will be thrown away).
protected abstract void	cancelImpl() Internal implementation of cancel().
protected void	checkBlobClosed()
protected void	checkBlobOpen()
protected void	checkDatabaseAttached()
protected void	checkTransactionActive()
protected void	clearDatabase()
protected void	clearTransaction()
void	close() Closes the blob.
protected abstract void	closeImpl() Internal implementation of close().
protected BlobLengthProcessor	createBlobLengthProcessor()
void	detached(FbDatabase database) Called when the database connection has been detached
void	detaching(FbDatabase database) Called before the database will be detached.
<T> T	getBlobInfo(byte[] requestItems, int bufferLength, InfoProcessor<T> infoProcessor) Request blob info.
protected BlobParameterBuffer	getBlobParameterBuffer()
FbDatabase	getDatabase()
int	getMaximumSegmentSize() The maximum segment size allowed by the protocol for FbBlob.getSegment(int) and FbBlob.putSegment(byte[]).
java.lang.Object	getSynchronizationObject() Get synchronization object.
protected FbTransaction	getTransaction()
protected boolean	isEndingTransaction()
boolean	isEof()
boolean	isOpen()
long	length() Requests the blob length from the server.
protected abstract void	releaseResources() Release Java resources held.
void	removeExceptionListener(ExceptionListener listener) Removes an exception listener to this object.
protected void	resetEof() Resets the eof state of the blob to false (not eof).
protected void	setEof() Marks this blob as EOF (End of file).
protected void	setOpen(boolean open) Sets the open state of the blob to the specified value.
void	transactionStateChanged(FbTransaction transaction, TransactionState newState, TransactionState previousState) Signals that the transaction state changed.
void	warningReceived(FbDatabase database, java.sql.SQLWarning warning) Called when a warning was received for the database connection.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.firebirdsql.gds.ng.FbBlob

getBlobId, getBlobInfo, getHandle, getSegment, isOutput, open, putSegment, seek

Field Detail

exceptionListenerDispatcher

protected final ExceptionListenerDispatcher exceptionListenerDispatcher

Constructor Detail

AbstractFbBlob

protected AbstractFbBlob(FbDatabase database,
                         FbTransaction transaction,
                         BlobParameterBuffer blobParameterBuffer)

Method Detail

isOpen

public final boolean isOpen()

Specified by:

isOpen in interface FbBlob

Returns:

true if this blob is currently open.

isEof

public final boolean isEof()

Specified by:

isEof in interface FbBlob

Returns:

true if this blob has reached the end or has been closed, always true for an open output blob.

setEof

protected final void setEof()

Marks this blob as EOF (End of file).

For an output blob this is a no-op (as those are never end of file, unless explicitly closed)

resetEof

protected final void resetEof()

Resets the eof state of the blob to false (not eof).

This method should only be called by sub-classes of this class.

setOpen

protected final void setOpen(boolean open)

Sets the open state of the blob to the specified value.

This method should only be called by sub-classes of this class.

Parameters:

open - New value of open.

close

public final void close()
                 throws java.sql.SQLException

Description copied from interface: FbBlob

Closes the blob.

Closing an already closed blob is a no-op.

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface FbBlob

Throws:

java.sql.SQLException - If the transaction is not active, or a database connection error occurred

closeImpl

protected abstract void closeImpl()
                           throws java.sql.SQLException

Internal implementation of close(). The implementation does not need to check for attached database and active transaction, nor does it need to mark this blob as closed.

Throws:

java.sql.SQLException

cancel

public final void cancel()
                  throws java.sql.SQLException

Description copied from interface: FbBlob

Cancels an output blob (which means its contents will be thrown away).

Calling cancel on an input blob will close it. Contrary to FbBlob.close(), calling cancel on an already closed (or cancelled) blob will throw an SQLException.

Specified by:

cancel in interface FbBlob

Throws:

java.sql.SQLException - If the blob has already been closed, the transaction is not active, or a database connection error occurred.

cancelImpl

protected abstract void cancelImpl()
                            throws java.sql.SQLException

Internal implementation of cancel(). The implementation does not need to check for attached database and active transaction, nor does it need to mark this blob as closed.

Throws:

java.sql.SQLException

releaseResources

protected abstract void releaseResources()

Release Java resources held. This should not communicate with the Firebird server.

getSynchronizationObject

public final java.lang.Object getSynchronizationObject()

Description copied from interface: FbBlob

Get synchronization object.

Specified by:

getSynchronizationObject in interface FbBlob

Returns:

object, cannot be null.

transactionStateChanged

public void transactionStateChanged(FbTransaction transaction,
                                    TransactionState newState,
                                    TransactionState previousState)

Description copied from interface: TransactionListener

Signals that the transaction state changed.

Specified by:

transactionStateChanged in interface TransactionListener

Parameters:

transaction - FbTransaction that changed state

detaching

public void detaching(FbDatabase database)

Description copied from interface: DatabaseListener

Called before the database will be detached.

This event is intended for cleanup action, implementer should take care that no exceptions are thrown from this method.

Specified by:

detaching in interface DatabaseListener

Parameters:

database - The database object that is detaching

detached

public void detached(FbDatabase database)

Description copied from interface: DatabaseListener

Called when the database connection has been detached

Specified by:

detached in interface DatabaseListener

Parameters:

database - The database object that was detached

warningReceived

public void warningReceived(FbDatabase database,
                            java.sql.SQLWarning warning)

Description copied from interface: DatabaseListener

Called when a warning was received for the database connection.

In implementation it is possible that some warnings are not sent to listeners on the database, but only to listeners on specific connection derived objects (like an FbStatement implementation).

Specified by:

warningReceived in interface DatabaseListener

Parameters:

database - Database receiving the warning

warning - Warning

isEndingTransaction

protected final boolean isEndingTransaction()

Returns:

true if the transaction is committing, rolling back or preparing

checkTransactionActive

protected final void checkTransactionActive()
                                     throws java.sql.SQLException

Throws:

java.sql.SQLException - When no transaction is set, or the transaction state is not TransactionState.ACTIVE

checkDatabaseAttached

protected void checkDatabaseAttached()
                              throws java.sql.SQLException

Throws:

java.sql.SQLException - When no database is set, or the database is not attached

checkBlobOpen

protected void checkBlobOpen()
                      throws java.sql.SQLException

Throws:

java.sql.SQLException - When the blob is closed.

checkBlobClosed

protected void checkBlobClosed()
                        throws java.sql.SQLException

Throws:

java.sql.SQLException - When the blob is open.

getTransaction

protected FbTransaction getTransaction()

clearTransaction

protected final void clearTransaction()

getDatabase

public FbDatabase getDatabase()

Specified by:

getDatabase in interface FbBlob

Returns:

The database connection that created this blob

getBlobInfo

public <T> T getBlobInfo(byte[] requestItems,
                         int bufferLength,
                         InfoProcessor<T> infoProcessor)
                  throws java.sql.SQLException

Description copied from interface: FbBlob

Request blob info.

Specified by:

getBlobInfo in interface FbBlob

Parameters:

requestItems - Array of info items to request

bufferLength - Response buffer length to use

infoProcessor - Implementation of InfoProcessor to transform the info response

Returns:

Transformed info response of type T

Throws:

java.sql.SQLException - For errors retrieving or transforming the response.

length

public long length()
            throws java.sql.SQLException

Description copied from interface: FbBlob

Requests the blob length from the server.

Specified by:

length in interface FbBlob

Returns:

Length of the blob.

Throws:

java.sql.SQLException - For Errors retrieving the length, or if the blob is not associated with a blob id, or the database is not attached.

addExceptionListener

public final void addExceptionListener(ExceptionListener listener)

Description copied from interface: ExceptionListenable

Adds an exception listener to this object.

Implementations use WeakReference.

Specified by:

addExceptionListener in interface ExceptionListenable

Parameters:

listener - Listener to register

removeExceptionListener

public final void removeExceptionListener(ExceptionListener listener)

Description copied from interface: ExceptionListenable

Removes an exception listener to this object.

Specified by:

removeExceptionListener in interface ExceptionListenable

Parameters:

listener - Listener to remove

clearDatabase

protected final void clearDatabase()

getBlobParameterBuffer

protected BlobParameterBuffer getBlobParameterBuffer()

Returns:

The blob parameter buffer of this blob.

createBlobLengthProcessor

protected BlobLengthProcessor createBlobLengthProcessor()

Returns:

New instance of BlobLengthProcessor (or subclass) for this blob.

getMaximumSegmentSize

public int getMaximumSegmentSize()

Description copied from interface: FbBlob

The maximum segment size allowed by the protocol for FbBlob.getSegment(int) and FbBlob.putSegment(byte[]).

This value is not the segment size (optionally) defined for the column.

Specified by:

getMaximumSegmentSize in interface FbBlob

Returns:

The maximum segment size allowed for get or put.