org.apache.derby.impl.drda
Class EXTDTAInputStream

java.lang.Object
  java.io.InputStream
      org.apache.derby.impl.drda.EXTDTAInputStream

All Implemented Interfaces:

java.io.Closeable

 class EXTDTAInputStream
extends java.io.InputStream

EXTDTAObjectHolder provides Externalized Large Object representation that does not hold locks until the end of the transaction (DERBY-255) It serves as a holder for lob data and is only valid as long as the original result set from which it came is on the same row.

Field Summary

private java.sql.Blob	_blob
private java.sql.Clob	_clob
private java.io.InputStream	binaryInputStream
(package private) int	columnNumber Column index starting with 1
(package private) int	ndrdaType DRDA Type of column/parameter
(package private) EngineResultSet	rs ResultSet that contains the stream

Constructor Summary

private	EXTDTAInputStream(java.sql.Blob blob, int ndrdaType)
private	EXTDTAInputStream(java.sql.Clob clob, int ndrdaType)
private	EXTDTAInputStream(java.sql.ResultSet rs, int columnNumber, int ndrdaType)

Method Summary

int	available()
private static void	badDRDAType(int drdaType)
void	close()
boolean	equals(java.lang.Object arg0)
protected void	finalize()
private java.io.InputStream	getBinaryStream()
private java.io.Reader	getCharacterStream()
static EXTDTAInputStream	getEXTDTAStream(java.sql.CallableStatement cs, int column, int drdaType) Create a new EXTDTAInputStream from a CallableStatement.
static EXTDTAInputStream	getEXTDTAStream(java.sql.ResultSet rs, int column, int drdaType) Create a new EXTDTAInputStream.
int	hashCode()
void	initInputStream() This method takes information of ResultSet and initializes the binaryInputStream variable of this object with not empty stream by calling getBinaryStream or getCharacterStream() as appropriate.
protected boolean	isEmptyStream()
boolean	isNull() Is the value null?
private long	length()
void	mark(int arg0)
boolean	markSupported()
int	read() Requires initInputStream() be called before we can read from the stream
int	read(byte[] arg0)
int	read(byte[] arg0, int arg1, int arg2)
void	reset()
long	skip(long arg0)

Methods inherited from class java.lang.Object

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

Field Detail

binaryInputStream

private java.io.InputStream binaryInputStream

ndrdaType

int ndrdaType

DRDA Type of column/parameter

rs

EngineResultSet rs

ResultSet that contains the stream

columnNumber

int columnNumber

Column index starting with 1

_clob

private java.sql.Clob _clob

_blob

private java.sql.Blob _blob

Constructor Detail

EXTDTAInputStream

private EXTDTAInputStream(java.sql.ResultSet rs,
                          int columnNumber,
                          int ndrdaType)

EXTDTAInputStream

private EXTDTAInputStream(java.sql.Clob clob,
                          int ndrdaType)

EXTDTAInputStream

private EXTDTAInputStream(java.sql.Blob blob,
                          int ndrdaType)

Method Detail

getEXTDTAStream

public static EXTDTAInputStream getEXTDTAStream(java.sql.ResultSet rs,
                                                int column,
                                                int drdaType)

Create a new EXTDTAInputStream. Before read the stream must be initialized by the user with initInputStream()

Parameters:

rs - result set from which to retrieve the lob

column - column number

drdaType - FD:OCA type of object one of DRDAConstants.DRDA_TYPE_NLOBBYTES DRDAConstants.DRDA_TYPE_LOBBYTES DRDAConstants.DRDA_TYPE_NLOBCMIXED DRDAConstants.DRDA_TYPE_LOBCMIXED

Returns:

null if the value is null or a new EXTDTAInputStream corresponding to rs.getBinaryStream(column) value and associated length

Throws:

java.sql.SQLException

See Also:

DDMWriter.writeScalarStream(boolean, int, org.apache.derby.impl.drda.EXTDTAInputStream, boolean), initInputStream()

getEXTDTAStream

public static EXTDTAInputStream getEXTDTAStream(java.sql.CallableStatement cs,
                                                int column,
                                                int drdaType)
                                         throws java.sql.SQLException

Create a new EXTDTAInputStream from a CallableStatement.

Parameters:

cs - CallableStatement from which to retrieve the lob

column - column number

drdaType - FD:OCA type of object one of DRDAConstants.DRDA_TYPE_NLOBBYTES DRDAConstants.DRDA_TYPE_LOBBYTES DRDAConstants.DRDA_TYPE_NLOBCMIXED DRDAConstants.DRDA_TYPE_LOBCMIXED

Throws:

java.sql.SQLException

read

public int read()
         throws java.io.IOException

Requires initInputStream() be called before we can read from the stream

Specified by:

read in class java.io.InputStream

Throws:

java.io.IOException

See Also:

InputStream.read()

available

public int available()
              throws java.io.IOException

Overrides:

available in class java.io.InputStream

Throws:

java.io.IOException

See Also:

InputStream.available()

close

public void close()
           throws java.io.IOException

Specified by:

close in interface java.io.Closeable

Overrides:

close in class java.io.InputStream

Throws:

java.io.IOException

See Also:

InputStream.close()

equals

public boolean equals(java.lang.Object arg0)

Overrides:

equals in class java.lang.Object

See Also:

Object.equals(java.lang.Object)

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

See Also:

Object.hashCode()

mark

public void mark(int arg0)

Overrides:

mark in class java.io.InputStream

See Also:

InputStream.mark(int)

markSupported

public boolean markSupported()

Overrides:

markSupported in class java.io.InputStream

See Also:

InputStream.markSupported()

read

public int read(byte[] arg0)
         throws java.io.IOException

Overrides:

read in class java.io.InputStream

Throws:

java.io.IOException

See Also:

InputStream.read(byte[])

read

public int read(byte[] arg0,
                int arg1,
                int arg2)
         throws java.io.IOException

Overrides:

read in class java.io.InputStream

Throws:

java.io.IOException

See Also:

InputStream.read(byte[], int, int)

reset

public void reset()
           throws java.io.IOException

Overrides:

reset in class java.io.InputStream

Throws:

java.io.IOException

See Also:

InputStream.reset()

skip

public long skip(long arg0)
          throws java.io.IOException

Overrides:

skip in class java.io.InputStream

Throws:

java.io.IOException

See Also:

InputStream.skip(long)

isEmptyStream

protected boolean isEmptyStream()
                         throws java.sql.SQLException

Throws:

java.sql.SQLException

length

private long length()
             throws java.sql.SQLException

Throws:

java.sql.SQLException

initInputStream

public void initInputStream()
                     throws java.sql.SQLException

This method takes information of ResultSet and initializes the binaryInputStream variable of this object with not empty stream by calling getBinaryStream or getCharacterStream() as appropriate. The Reader returned from getCharacterStream() will be encoded in binarystream.

Throws:

java.sql.SQLException

getBinaryStream

private java.io.InputStream getBinaryStream()
                                     throws java.sql.SQLException

Throws:

java.sql.SQLException

getCharacterStream

private java.io.Reader getCharacterStream()
                                   throws java.sql.SQLException

Throws:

java.sql.SQLException

badDRDAType

private static void badDRDAType(int drdaType)

finalize

protected void finalize()
                 throws java.lang.Throwable

Overrides:

finalize in class java.lang.Object

Throws:

java.lang.Throwable

isNull

public boolean isNull()
               throws java.sql.SQLException

Is the value null? Null status is obtained from the underlying EngineResultSet or LOB, so that it can be determined before the stream is retrieved.

Returns:

true if this value is null

Throws:

java.sql.SQLException