Apache Derby Client JDBC Driver 10.17.1.0 · org.apache.derby.client.am.UpdateSensitiveClobLocatorReader

Modifier and Type	Field and Description
private ClientClob	clob
private ClientConnection	con
private long	currentPos
private long	length
private BufferedReader	r
private long	updateCount

Constructor Summary

Access Constructor and Description

protected

Access	Constructor and Description
protected	UpdateSensitiveClobLocatorReader(ClientConnection connection to be used to read the `Clob` value from the server con, ClientClob the `Clob` object associated with this stream. clob) Initializes the Reader, updateCount, currentPos and the connection to the appropriate values.
protected	UpdateSensitiveClobLocatorReader(ClientConnection connection to be used to read the `Clob` value from the server con, ClientClob the `Clob` object associated with this reader. clob, long the position from which the first read begins. pos, long the length in bytes of the partial value to be retrieved. len) Initializes the Reader, updateCount, currentPos, length and the connection to the appropriate values.

UpdateSensitiveClobLocatorReader(ClientConnection

connection to be used to read the Clob value from the server

con, ClientClob

the Clob object associated with this stream.

clob)

Initializes the Reader, updateCount, currentPos and the connection to the appropriate values.

protected

UpdateSensitiveClobLocatorReader(ClientConnection

connection to be used to read the Clob value from the server

con, ClientClob

the Clob object associated with this reader.

clob, long

the position from which the first read begins.

pos, long

the length in bytes of the partial value to be retrieved.

len)

Initializes the Reader, updateCount, currentPos, length and the connection to the appropriate values.

Method Summary

Modifier and Type	Method and Description
public void	close() Implements abstract java.io.Reader.close. Implements java.io.Closeable.close. Closes the stream and releases any system resources associated with it.
private void	identifyAndReplaceObseleteStream() Verifies whether the current updateCount matches the updateCount of the Clob object and if it does not it recreates the stream.
public int	read() Overrides java.io.Reader.read. Reads a single character.
public int	read(char[] Destination buffer c, int Offset at which to start storing characters off, int Maximum number of characters to read len) Implements abstract java.io.Reader.read. Reads characters into a portion of an array.
private Reader	reCreateStream() Re-creates the underlying Locator stream with the current position and the length values if specified.

Inherited from java.io.Reader:: mark markSupported nullReader read read ready reset skip transferTo

Field Detail

clob	back to summary
private ClientClob clob

con	back to summary
private ClientConnection con

currentPos	back to summary
private long currentPos

length	back to summary
private long length

r	back to summary
private BufferedReader r

updateCount	back to summary
private long updateCount

Constructor Detail

UpdateSensitiveClobLocatorReader back to summary

UpdateSensitiveClobLocatorReader	back to summary
protected UpdateSensitiveClobLocatorReader(ClientConnection con, ClientClob clob) throws SqlException Initializes the Reader, updateCount, currentPos and the connection to the appropriate values. Parameters con:ClientConnection connection to be used to read the `Clob` value from the server clob:ClientClob the `Clob` object associated with this stream.

protected UpdateSensitiveClobLocatorReader(ClientConnection con, ClientClob clob) throws SqlException

Initializes the Reader, updateCount, currentPos and the connection to the appropriate values.

Parameters

con:ClientConnection: connection to be used to read the Clob value from the server
clob:ClientClob: the Clob object associated with this stream.

UpdateSensitiveClobLocatorReader back to summary

UpdateSensitiveClobLocatorReader	back to summary
protected UpdateSensitiveClobLocatorReader(ClientConnection con, ClientClob clob, long pos, long len) throws SqlException Initializes the Reader, updateCount, currentPos, length and the connection to the appropriate values. Parameters con:ClientConnection connection to be used to read the `Clob` value from the server clob:ClientClob the `Clob` object associated with this reader. pos:long the position from which the first read begins. len:long the length in bytes of the partial value to be retrieved.

protected UpdateSensitiveClobLocatorReader(ClientConnection con, ClientClob clob, long pos, long len) throws SqlException

Initializes the Reader, updateCount, currentPos, length and the connection to the appropriate values.

Parameters

con:ClientConnection: connection to be used to read the Clob value from the server
clob:ClientClob: the Clob object associated with this reader.
pos:long: the position from which the first read begins.
len:long: the length in bytes of the partial value to be retrieved.

Method Detail

close back to summary

close	back to summary
public void close() throws IOException Implements abstract java.io.Reader.close. Implements java.io.Closeable.close. Doc from java.io.Reader.close. Closes the stream and releases any system resources associated with it. Once the stream has been closed, further read(), ready(), mark(), reset(), or skip() invocations will throw an IOException. Closing a previously closed stream has no effect. Exceptions IOException: If an I/O error occurs See Also `java.io.Reader#close()`

public void close() throws IOException

Implements abstract java.io.Reader.close.

Implements java.io.Closeable.close.

Doc from java.io.Reader.close.

Closes the stream and releases any system resources associated with it. Once the stream has been closed, further read(), ready(), mark(), reset(), or skip() invocations will throw an IOException. Closing a previously closed stream has no effect.

Exceptions

IOException:: If an I/O error occurs

See Also

java.io.Reader#close()

identifyAndReplaceObseleteStream	back to summary
private void identifyAndReplaceObseleteStream() throws IOException Verifies whether the current updateCount matches the updateCount of the Clob object and if it does not it recreates the stream. Exceptions IOException: If any exception occurs upon Locator stream creation.

identifyAndReplaceObseleteStream

back to summary

private void identifyAndReplaceObseleteStream() throws IOException

Verifies whether the current updateCount matches the updateCount of the Clob object and if it does not it recreates the stream.

Exceptions

IOException:: If any exception occurs upon Locator stream creation.

read back to summary

read	back to summary
public int read() throws IOException Overrides java.io.Reader.read. Doc from java.io.Reader.read. Reads a single character. This method will block until a character is available, an I/O error occurs, or the end of the stream is reached. Subclasses that intend to support efficient single-character input should override this method. Returns:int The character read, as an integer in the range 0 to 65535 (`0x00-0xffff`), or -1 if the end of the stream has been reached Exceptions IOException: If an I/O error occurs See Also `java.io.Reader#read()`

public int read() throws IOException

Overrides java.io.Reader.read.

Doc from java.io.Reader.read.

Reads a single character. This method will block until a character is available, an I/O error occurs, or the end of the stream is reached.

Subclasses that intend to support efficient single-character input should override this method.

Returns:int

The character read, as an integer in the range 0 to 65535 (0x00-0xffff), or -1 if the end of the stream has been reached

Exceptions

IOException:: If an I/O error occurs

See Also

java.io.Reader#read()

read back to summary

read	back to summary
public int read(char[] c, int off, int len) throws IOException Implements abstract java.io.Reader.read. Doc from java.io.Reader.read. Reads characters into a portion of an array. This method will block until some input is available, an I/O error occurs, or the end of the stream is reached. If `len` is zero, then no characters are read and `0` is returned; otherwise, there is an attempt to read at least one character. If no character is available because the stream is at its end, the value `-1` is returned; otherwise, at least one character is read and stored into `cbuf`. Parameters c:char[] Destination buffer off:int Offset at which to start storing characters len:int Maximum number of characters to read Returns:int The number of characters read, or -1 if the end of the stream has been reached Exceptions IOException: If an I/O error occurs See Also `java.io.Reader#read(char[], int, int)`

public int read(char[] c, int off, int len) throws IOException

Implements abstract java.io.Reader.read.

Doc from java.io.Reader.read.

Reads characters into a portion of an array. This method will block until some input is available, an I/O error occurs, or the end of the stream is reached.

If len is zero, then no characters are read and 0 is returned; otherwise, there is an attempt to read at least one character. If no character is available because the stream is at its end, the value -1 is returned; otherwise, at least one character is read and stored into cbuf.

Parameters

c:char[]: Destination buffer
off:int: Offset at which to start storing characters
len:int: Maximum number of characters to read

Returns:int

The number of characters read, or -1 if the end of the stream has been reached

Exceptions

IOException:: If an I/O error occurs

See Also

java.io.Reader#read(char[], int, int)

reCreateStream	back to summary
private Reader reCreateStream() throws SqlException Re-creates the underlying Locator stream with the current position and the length values if specified.

pack-priv Class UpdateSensitiveClobLocatorReader

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail