Package org.firebirdsql.gds.ng.jna

Class JnaBlob

java.lang.Object

org.firebirdsql.gds.ng.AbstractFbBlob

org.firebirdsql.gds.ng.jna.JnaBlob

All Implemented Interfaces:

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

public class JnaBlob
extends AbstractFbBlob
implements FbBlob, DatabaseListener

Implementation of FbBlob for native client access.

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 inherited from class org.firebirdsql.gds.ng.AbstractFbBlob

exceptionListenerDispatcher

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

NO_BLOB_ID

Constructor Summary

Constructors

Constructor	Description
JnaBlob(JnaDatabase database, JnaTransaction transaction, BlobParameterBuffer blobParameterBuffer)
JnaBlob(JnaDatabase database, JnaTransaction transaction, BlobParameterBuffer blobParameterBuffer, long blobId)

Method Summary

Modifier and Type	Method	Description
protected void	cancelImpl()	Internal implementation of AbstractFbBlob.cancel().
protected void	closeImpl()	Internal implementation of AbstractFbBlob.close().
long	getBlobId()
byte[]	getBlobInfo(byte[] requestItems, int bufferLength)	Request blob info.
JnaDatabase	getDatabase()
int	getHandle()
com.sun.jna.ptr.IntByReference	getJnaHandle()
byte[]	getSegment(int sizeRequested)	Gets a segment of blob data.
JnaTransaction	getTransaction()
boolean	isOutput()
void	open()	Opens an existing input blob, or creates an output blob.
void	putSegment(byte[] segment)	Writes a segment of blob data.
protected void	releaseResources()	Release Java resources held.
void	seek(int offset, FbBlob.SeekMode seekMode)	Performs a seek on a blob with the specified seekMode and offset.

Methods inherited from class org.firebirdsql.gds.ng.AbstractFbBlob

addExceptionListener, cancel, checkBlobClosed, checkBlobOpen, checkDatabaseAttached, checkTransactionActive, clearDatabase, clearTransaction, close, createBlobLengthProcessor, detached, detaching, getBlobInfo, getBlobParameterBuffer, getMaximumSegmentSize, getSynchronizationObject, isEndingTransaction, isEof, isOpen, length, removeExceptionListener, resetEof, setEof, setOpen, transactionStateChanged, warningReceived

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.listeners.DatabaseListener

detached, detaching, warningReceived

Methods inherited from interface org.firebirdsql.gds.ng.listeners.ExceptionListenable

addExceptionListener, removeExceptionListener

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

cancel, close, getBlobInfo, getMaximumSegmentSize, getSynchronizationObject, isEof, isOpen, length

Constructor Detail

JnaBlob

public JnaBlob(JnaDatabase database,
               JnaTransaction transaction,
               BlobParameterBuffer blobParameterBuffer)

JnaBlob

public JnaBlob(JnaDatabase database,
               JnaTransaction transaction,
               BlobParameterBuffer blobParameterBuffer,
               long blobId)

Method Detail

getDatabase

public JnaDatabase getDatabase()

Specified by:

getDatabase in interface FbBlob

Overrides:

getDatabase in class AbstractFbBlob

Returns:

The database connection that created this blob

getTransaction

public JnaTransaction getTransaction()

Overrides:

getTransaction in class AbstractFbBlob

getHandle

public int getHandle()

Specified by:

getHandle in interface FbBlob

Returns:

The Firebird blob handle identifier

getJnaHandle

public final com.sun.jna.ptr.IntByReference getJnaHandle()

getBlobId

public final long getBlobId()

Specified by:

getBlobId in interface FbBlob

Returns:

The Firebird blob id

open

public void open()
          throws java.sql.SQLException

Description copied from interface: FbBlob

Opens an existing input blob, or creates an output blob.

Specified by:

open in interface FbBlob

Throws:

java.sql.SQLException - If the blob is already open, this is a (closed) output blob and it already has a blobId, the transaction is not active, or a database connection error occurred

isOutput

public final boolean isOutput()

Specified by:

isOutput in interface FbBlob

Returns:

true if this is an output blob (write only), false if this is an input blob (read only)

getSegment

public byte[] getSegment(int sizeRequested)
                  throws java.sql.SQLException

Description copied from interface: FbBlob

Gets a segment of blob data.

When sizeRequested exceeds FbBlob.getMaximumSegmentSize() it is silently reduced to the maximum segment size.

TODO: Consider allowing this and have the implementation handle longer segments by sending multiple (batched?) requests.

Specified by:

getSegment in interface FbBlob

Parameters:

sizeRequested - Requested segment size (> 0).

Returns:

Retrieved segment (size may be less than requested)

Throws:

java.sql.SQLException - If this is an output blob, the blob is closed, the transaction is not active, or a database connection error occurred.

putSegment

public void putSegment(byte[] segment)
                throws java.sql.SQLException

Description copied from interface: FbBlob

Writes a segment of blob data.

Implementation must handle segment length exceeding FbBlob.getMaximumSegmentSize() by batching. TODO: reconsider and let caller handle that?

Passing a section that is length 0 will throw an SQLException.

Specified by:

putSegment in interface FbBlob

Parameters:

segment - Segment to write

Throws:

java.sql.SQLException - If this is an input blob, the blob is closed, the transaction is not active, the segment is length 0 or longer than the maximum segment size, or a database connection error occurred.

seek

public void seek(int offset,
                 FbBlob.SeekMode seekMode)
          throws java.sql.SQLException

Description copied from interface: FbBlob

Performs a seek on a blob with the specified seekMode and offset.

Firebird only supports seek on stream blobs.

Specified by:

seek in interface FbBlob

Parameters:

offset - Offset of the seek, effect depends on value of seekMode

seekMode - Value of FbBlob.SeekMode

Throws:

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

getBlobInfo

public byte[] getBlobInfo(byte[] requestItems,
                          int bufferLength)
                   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

Returns:

Response buffer

Throws:

java.sql.SQLException

closeImpl

protected void closeImpl()
                  throws java.sql.SQLException

Description copied from class: AbstractFbBlob

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

Specified by:

closeImpl in class AbstractFbBlob

Throws:

java.sql.SQLException

cancelImpl

protected void cancelImpl()
                   throws java.sql.SQLException

Description copied from class: AbstractFbBlob

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

Specified by:

cancelImpl in class AbstractFbBlob

Throws:

java.sql.SQLException

releaseResources

protected void releaseResources()

Description copied from class: AbstractFbBlob

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

Specified by:

releaseResources in class AbstractFbBlob