Apache Derby Database Engine and Embedded JDBC Driver 10.17.1.0 · org.apache.derby.impl.jdbc.StoreStreamClob

Modifier and Type	Field and Description
private final ConnectionChild	conChild The connection (child) this Clob belongs to.
private CharacterStreamDescriptor	csd The descriptor used to describe the underlying source stream.
private UTF8Reader	internalReader Shared internal reader, closed when the Clob is released.
private final PositionedStoreStream	positionedStoreStream The stream from store, used to read bytes from the database.
private volatile boolean	released Tells whether this Clob has been released or not.
private final Object	synchronizationObject Object used for synchronizing access to the store stream.
private FilterReader	unclosableInternalReader The internal reader wrapped so that it cannot be closed.

Access	Constructor and Description
public	StoreStreamClob(CharacterStreamDescriptor descriptor for the source stream, including a reference to it csd, ConnectionChild the connection (child) this Clob belongs to conChild) Creates a new Clob based on a stream from store.

Method Summary

Modifier and Type	Method and Description
private void	checkIfValid() Makes sure the Clob has not been released.
public long	Returns: Number of characters in the Clob. getCharLength() Implements org.apache.derby.impl.jdbc.InternalClob.getCharLength. Returns the number of characters in the Clob.
public long	Returns: The number of characters in the Clob, or `-1` if unknown. getCharLengthIfKnown() Implements org.apache.derby.impl.jdbc.InternalClob.getCharLengthIfKnown. Returns the cached character count for the Clob, if any.
public Reader	Returns: A reader initialized at the specified position. getInternalReader(long 1-based character position. characterPosition) Implements org.apache.derby.impl.jdbc.InternalClob.getInternalReader. Returns an internal reader for the Clob, initialized at the specified character position.
public InputStream	Returns: A stream serving the bytes of this Clob, initialized at byte 0 of the data. The buffer must be assumed to be unbuffered, but no such guarantee is made. getRawByteStream() Implements org.apache.derby.impl.jdbc.InternalClob.getRawByteStream. Returns a stream serving the raw bytes of this Clob.
public Reader	Returns: A reader initialized at the specified position. getReader(long character position. The first character is at position 1. pos) Implements org.apache.derby.impl.jdbc.InternalClob.getReader. Returns a reader for the Clob, initialized at the specified character position.
public long	Returns: Zero (read-only Clob). getUpdateCount() Implements org.apache.derby.impl.jdbc.InternalClob.getUpdateCount. Returns the update count of this Clob.
public Writer	getWriter(long the starting character position. The first character is at position `1`. pos) Implements org.apache.derby.impl.jdbc.InternalClob.getWriter. Not supported.
public long	insertString(String the string to insert str, long the character position the string will be inserted at. Must be between `1` and `clob.length() +1`, inclusive. pos) Implements org.apache.derby.impl.jdbc.InternalClob.insertString. Not supported.
public boolean	Returns: `true` if released, `false` if not. isReleased() Implements org.apache.derby.impl.jdbc.InternalClob.isReleased. Tells if this Clob has been released.
public boolean	Returns: `false`, this Clob is read-only. isWritable() Implements org.apache.derby.impl.jdbc.InternalClob.isWritable. Tells if this Clob can be modified.
private static SQLException	Returns: A `SQLException` wrapped around the real cause of the error noStateChangeLOB(Throwable real cause of error that we want to "ignore" with respect to transaction context cleanup t) Wrap real exception in a `SQLException` to avoid changing the state of the connection child by cleaning it up.
public void	release() Implements org.apache.derby.impl.jdbc.InternalClob.release. Releases resources associated with this Clob.
public void	truncate(long the length in characters to truncate to newLength) Implements org.apache.derby.impl.jdbc.InternalClob.truncate. Not supported.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

conChild	back to summary
private final ConnectionChild conChild The connection (child) this Clob belongs to.

csd	back to summary
private CharacterStreamDescriptor csd The descriptor used to describe the underlying source stream.

internalReader back to summary

internalReader	back to summary
private UTF8Reader internalReader Shared internal reader, closed when the Clob is released. This is a performance optimization, and the stream is shared between "one time" operations, for instance `getSubString` calls. Often a subset, or the whole, of the Clob is read subsequently and then this optimization avoids repositioning costs (the store does not support random access for LOBs) Note Do not publish this reader to the end-user.

private UTF8Reader internalReader

Shared internal reader, closed when the Clob is released. This is a performance optimization, and the stream is shared between "one time" operations, for instance getSubString calls. Often a subset, or the whole, of the Clob is read subsequently and then this optimization avoids repositioning costs (the store does not support random access for LOBs)

Note

Do not publish this reader to the end-user.

positionedStoreStream back to summary

positionedStoreStream	back to summary
private final PositionedStoreStream positionedStoreStream The stream from store, used to read bytes from the database. To be able to support the requirements, the stream must implement `Resetable`.

private final PositionedStoreStream positionedStoreStream

The stream from store, used to read bytes from the database.

To be able to support the requirements, the stream must implement Resetable.

released	back to summary
private volatile boolean released Tells whether this Clob has been released or not.

synchronizationObject	back to summary
private final Object synchronizationObject Object used for synchronizing access to the store stream.

unclosableInternalReader	back to summary
private FilterReader unclosableInternalReader The internal reader wrapped so that it cannot be closed.

Constructor Detail

StoreStreamClob back to summary

StoreStreamClob	back to summary
public StoreStreamClob(CharacterStreamDescriptor csd, ConnectionChild conChild) throws StandardException Creates a new Clob based on a stream from store. The stream used as a source for this Clob has to implement the interface `Resetable`, as the stream interface from store only allows for movement forwards. If the stream has been advanced too far with regards to the user request, the stream must be reset and we start from the beginning. Parameters csd:CharacterStreamDescriptor descriptor for the source stream, including a reference to it conChild:ConnectionChild the connection (child) this Clob belongs to

public StoreStreamClob(CharacterStreamDescriptor csd, ConnectionChild conChild) throws StandardException

Creates a new Clob based on a stream from store.

The stream used as a source for this Clob has to implement the interface Resetable, as the stream interface from store only allows for movement forwards. If the stream has been advanced too far with regards to the user request, the stream must be reset and we start from the beginning.

Parameters

csd:CharacterStreamDescriptor: descriptor for the source stream, including a reference to it
conChild:ConnectionChild: the connection (child) this Clob belongs to

Method Detail

checkIfValid	back to summary
private void checkIfValid() Makes sure the Clob has not been released. All operations are invalid on a released Clob. Exceptions IllegalStateException: if the Clob has been released

checkIfValid

back to summary

private void checkIfValid()

Makes sure the Clob has not been released.

All operations are invalid on a released Clob.

Exceptions

IllegalStateException:: if the Clob has been released

getCharLength	back to summary
public long getCharLength() throws SQLException Implements org.apache.derby.impl.jdbc.InternalClob.getCharLength. Returns the number of characters in the Clob. Returns:long Number of characters in the Clob. Exceptions SQLException: if any kind of error is encountered, be it related to I/O or something else

getCharLength

back to summary

public long getCharLength() throws SQLException

Implements org.apache.derby.impl.jdbc.InternalClob.getCharLength.

Returns the number of characters in the Clob.

Returns:long

Number of characters in the Clob.

Exceptions

SQLException:: if any kind of error is encountered, be it related to I/O or something else

getCharLengthIfKnown back to summary

getCharLengthIfKnown	back to summary
public long getCharLengthIfKnown() Implements org.apache.derby.impl.jdbc.InternalClob.getCharLengthIfKnown. Returns the cached character count for the Clob, if any. Returns:long The number of characters in the Clob, or `-1` if unknown.

public long getCharLengthIfKnown()

Implements org.apache.derby.impl.jdbc.InternalClob.getCharLengthIfKnown.

Returns the cached character count for the Clob, if any.

Returns:long: The number of characters in the Clob, or -1 if unknown.

getInternalReader	back to summary
public Reader getInternalReader(long characterPosition) throws IOException, SQLException Implements org.apache.derby.impl.jdbc.InternalClob.getInternalReader. Returns an internal reader for the Clob, initialized at the specified character position. Parameters characterPosition:long 1-based character position. Returns:Reader A reader initialized at the specified position. Exceptions IOException: if accessing the I/O resources fail SQLException: if accessing the store resources fail EOFException: if the positions is larger than the Clob

getInternalReader

back to summary

public Reader getInternalReader(long characterPosition) throws IOException, SQLException

Implements org.apache.derby.impl.jdbc.InternalClob.getInternalReader.

Returns an internal reader for the Clob, initialized at the specified character position.

Parameters

characterPosition:long: 1-based character position.

Returns:Reader

A reader initialized at the specified position.

Exceptions

IOException:: if accessing the I/O resources fail
SQLException:: if accessing the store resources fail
EOFException:: if the positions is larger than the Clob

getRawByteStream	back to summary
public InputStream getRawByteStream() throws IOException, SQLException Implements org.apache.derby.impl.jdbc.InternalClob.getRawByteStream. Returns a stream serving the raw bytes of this Clob. Note that the stream returned is an internal stream, and it should not be pulished to end users. Returns:InputStream A stream serving the bytes of this Clob, initialized at byte 0 of the data. The buffer must be assumed to be unbuffered, but no such guarantee is made. Exceptions IOException: if accessing the I/O resources fail SQLException: if accessing the store resources fail

getRawByteStream

back to summary

public InputStream getRawByteStream() throws IOException, SQLException

Implements org.apache.derby.impl.jdbc.InternalClob.getRawByteStream.

Returns a stream serving the raw bytes of this Clob.

Note that the stream returned is an internal stream, and it should not be pulished to end users.

Returns:InputStream

A stream serving the bytes of this Clob, initialized at byte 0 of the data. The buffer must be assumed to be unbuffered, but no such guarantee is made.

Exceptions

IOException:: if accessing the I/O resources fail
SQLException:: if accessing the store resources fail

getReader	back to summary
public Reader getReader(long pos) throws IOException, SQLException Implements org.apache.derby.impl.jdbc.InternalClob.getReader. Returns a reader for the Clob, initialized at the specified character position. Parameters pos:long character position. The first character is at position 1. Returns:Reader A reader initialized at the specified position. Exceptions IOException: if accessing the I/O resources fail SQLException: if accessing the store resources fail EOFException: if the positions is larger than the Clob

getReader

back to summary

public Reader getReader(long pos) throws IOException, SQLException

Implements org.apache.derby.impl.jdbc.InternalClob.getReader.

Returns a reader for the Clob, initialized at the specified character position.

Parameters

pos:long: character position. The first character is at position 1.

Returns:Reader

A reader initialized at the specified position.

Exceptions

IOException:: if accessing the I/O resources fail
SQLException:: if accessing the store resources fail
EOFException:: if the positions is larger than the Clob

getUpdateCount	back to summary
public long getUpdateCount() Implements org.apache.derby.impl.jdbc.InternalClob.getUpdateCount. Returns the update count of this Clob. Always returns zero, as this Clob cannot be updated. Returns:long Zero (read-only Clob).

getUpdateCount

back to summary

public long getUpdateCount()

Implements org.apache.derby.impl.jdbc.InternalClob.getUpdateCount.

Returns the update count of this Clob.

Always returns zero, as this Clob cannot be updated.

Returns:long: Zero (read-only Clob).

getWriter back to summary

getWriter	back to summary
public Writer getWriter(long pos) Implements org.apache.derby.impl.jdbc.InternalClob.getWriter. Not supported. Parameters pos:long Doc from org.apache.derby.impl.jdbc.InternalClob.getWriter. the starting character position. The first character is at position `1`. Returns:Writer Doc from org.apache.derby.impl.jdbc.InternalClob.getWriter. A writer initialized at the specified character position. See Also `InternalClob#getWriter`

public Writer getWriter(long pos)

Implements org.apache.derby.impl.jdbc.InternalClob.getWriter.

Not supported.

Parameters

pos:long

Doc from org.apache.derby.impl.jdbc.InternalClob.getWriter.

the starting character position. The first character is at position 1.

Returns:Writer

Doc from org.apache.derby.impl.jdbc.InternalClob.getWriter.

A writer initialized at the specified character position.

See Also

InternalClob#getWriter

insertString back to summary

insertString	back to summary
public long insertString(String str, long pos) Implements org.apache.derby.impl.jdbc.InternalClob.insertString. Not supported. Parameters str:String Doc from org.apache.derby.impl.jdbc.InternalClob.insertString. the string to insert pos:long Doc from org.apache.derby.impl.jdbc.InternalClob.insertString. the character position the string will be inserted at. Must be between `1` and `clob.length() +1`, inclusive. Returns:long Doc from org.apache.derby.impl.jdbc.InternalClob.insertString. The number of characters inserted. See Also `InternalClob#insertString`

public long insertString(String str, long pos)

Implements org.apache.derby.impl.jdbc.InternalClob.insertString.

Not supported.

Parameters

str:String

Doc from org.apache.derby.impl.jdbc.InternalClob.insertString.

the string to insert

pos:long

Doc from org.apache.derby.impl.jdbc.InternalClob.insertString.

the character position the string will be inserted at. Must be between 1 and clob.length() +1, inclusive.

Returns:long

Doc from org.apache.derby.impl.jdbc.InternalClob.insertString.

The number of characters inserted.

See Also

InternalClob#insertString

isReleased back to summary

isReleased	back to summary
public boolean isReleased() Implements org.apache.derby.impl.jdbc.InternalClob.isReleased. Tells if this Clob has been released. Returns:boolean `true` if released, `false` if not.

public boolean isReleased()

Implements org.apache.derby.impl.jdbc.InternalClob.isReleased.

Tells if this Clob has been released.

Returns:boolean: true if released, false if not.

isWritable back to summary

isWritable	back to summary
public boolean isWritable() Implements org.apache.derby.impl.jdbc.InternalClob.isWritable. Tells if this Clob can be modified. Returns:boolean `false`, this Clob is read-only.

public boolean isWritable()

Implements org.apache.derby.impl.jdbc.InternalClob.isWritable.

Tells if this Clob can be modified.

Returns:boolean: false, this Clob is read-only.

noStateChangeLOB back to summary

noStateChangeLOB	back to summary
private static SQLException noStateChangeLOB(Throwable t) Wrap real exception in a `SQLException` to avoid changing the state of the connection child by cleaning it up. Parameters t:Throwable real cause of error that we want to "ignore" with respect to transaction context cleanup Returns:SQLException A `SQLException` wrapped around the real cause of the error

private static SQLException noStateChangeLOB(Throwable t)

Wrap real exception in a SQLException to avoid changing the state of the connection child by cleaning it up.

Parameters

t:Throwable: real cause of error that we want to "ignore" with respect to transaction context cleanup

Returns:SQLException

A SQLException wrapped around the real cause of the error

release	back to summary
public void release() Implements org.apache.derby.impl.jdbc.InternalClob.release. Releases resources associated with this Clob.

release

back to summary

public void release()

Implements org.apache.derby.impl.jdbc.InternalClob.release.

Releases resources associated with this Clob.

truncate back to summary

truncate	back to summary
public void truncate(long newLength) Implements org.apache.derby.impl.jdbc.InternalClob.truncate. Not supported. Parameters newLength:long Doc from org.apache.derby.impl.jdbc.InternalClob.truncate. the length in characters to truncate to See Also `InternalClob#truncate`

public void truncate(long newLength)

Implements org.apache.derby.impl.jdbc.InternalClob.truncate.

Not supported.

Parameters

newLength:long

Doc from org.apache.derby.impl.jdbc.InternalClob.truncate.

the length in characters to truncate to

See Also

InternalClob#truncate

pack-priv final Class StoreStreamClob

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail