Package org.firebirdsql.gds.ng.jna

Class JnaBlob

    • Constructor Detail

      • JnaBlob

        public JnaBlob​(JnaDatabase database,
               JnaTransaction transaction,
               BlobParameterBuffer blobParameterBuffer)
        throws java.sql.SQLException
        Creates a blob for output (writing to the database).
        Parameters:
        database - database
        transaction - transaction
        blobParameterBuffer - blob parameter buffer
        Throws:
        java.sql.SQLException

      • JnaBlob

        public JnaBlob​(JnaDatabase database,
               JnaTransaction transaction,
               BlobParameterBuffer blobParameterBuffer,
               long blobId)
        throws java.sql.SQLException
        Creates a blob for input (reading from the database).
        Parameters:
        database - database
        transaction - transaction
        blobParameterBuffer - blob parameter buffer
        blobId - blob id
        Throws:
        java.sql.SQLException

    • Method Detail

      • getHandle

        public int getHandle()
        Description copied from interface: FbBlob
        Returns the blob handle identifier.

        If the blob wasn't opened yet, this will return 0. If the blob was deferred opened (client-side only), this will return an invalid blob handle value (e.g. 0xFFFF, though this value is potentially protocol/implementation specific).

        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()
        Description copied from interface: FbBlob
        Returns the blob id.

        For output blobs, this will return FbBlob.NO_BLOB_ID (0L) if the blob wasn't opened yet, or if the blob is deferred opened (client-side only). The value FbBlob.NO_BLOB_ID is technically invalid, but Firebird will handle it as an empty blob (both for input and output).

        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.

        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.
        See Also:
        FbBlob.get(byte[], int, int)

      • get

        protected int get​(byte[] b,
                  int off,
                  int len,
                  int minLen)
           throws java.sql.SQLException
        Description copied from class: AbstractFbBlob
        Default implementation for AbstractFbBlob.get(byte[], int, int) and AbstractFbBlob.get(byte[], int, int, float).
        Specified by:
        get in class AbstractFbBlob
        Parameters:
        b - target byte array
        off - offset to start
        len - number of bytes
        minLen - minimum number of bytes to fill (must be 0 < minLen <= len if len != 0
        Returns:
        actual number of bytes read; is 0 if len == 0, will only be less than minLen if end-of-blob is reached
        Throws:
        java.sql.SQLException - for database access errors, if off < 0, len < 0, or if off + len > b.length, or len != 0 && (minLen <= 0 || minLen > len)

      • put

        public void put​(byte[] b,
                int off,
                int len)
         throws java.sql.SQLException
        Description copied from interface: FbBlob
        Writes content of b starting at off for length bytes to the blob.

        Implementations must write all bytes to the blob, using multiple round-trips if necessary.

        If the implementation cannot perform writes without additional allocation, it should use at most DatabaseConnectionProperties.getBlobBufferSize() as an internal buffer. If the implementation can perform writes without additional allocation, it is recommended it performs reads using (at most) FbBlob.getMaximumSegmentSize().

        Specified by:
        put in interface FbBlob
        Parameters:
        b - source byte array
        off - offset to start
        len - number of bytes
        Throws:
        java.sql.SQLException - for database access errors, if off < 0, len < 0, or if off + len > b.length

      • 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