net.sourceforge.jtds.jdbc

Class ClobImpl

java.lang.Object

net.sourceforge.jtds.jdbc.ClobImpl

All Implemented Interfaces:

java.sql.Clob

public class ClobImpl
extends java.lang.Object
implements java.sql.Clob

An in-memory or disk based representation of character data.

Implementation note:

1. This implementation stores the CLOB data in a byte array managed by the BlobBuffer class. Each character is stored in 2 sequential bytes using UTF-16LE encoding.
2. As a consequence of using UTF-16LE, Unicode 3.1 supplementary characters may require an additional 2 bytes of storage. This implementation assumes that character position parameters supplied to getSubstring, position and the set methods refer to 16 bit characters only. The presence of supplementary characters will cause the wrong characters to be accessed.
3. For the same reasons although the position method will return the correct start position for any given pattern in the array, the returned value may be different to that expected if supplementary characters exist in the text preceding the pattern.

Version:

$Id: ClobImpl.java,v 1.36.2.3 2009-12-30 08:45:34 ickzon Exp $

Author:

Brian Heineman, Mike Hutchinson

Field Summary

Fields

Modifier and Type	Field and Description
private BlobBuffer	blobBuffer The underlying BlobBuffer.
private static java.lang.String	EMPTY_CLOB 0 length String as initial value for empty Clobs.

Constructor Summary

Constructors

Constructor and Description
ClobImpl(JtdsConnection connection) Constructs a new empty Clob instance.
ClobImpl(JtdsConnection connection, java.lang.String str) Constructs a new initialized Clob instance.

Method Summary

Methods

Modifier and Type	Method and Description
void	free()
java.io.InputStream	getAsciiStream()
(package private) BlobBuffer	getBlobBuffer() Obtain this object's backing BlobBuffer object.
java.io.Reader	getCharacterStream()
java.io.Reader	getCharacterStream(long pos, long length)
java.lang.String	getSubString(long pos, int length)
long	length()
long	position(java.sql.Clob searchStr, long start)
long	position(java.lang.String searchStr, long start)
java.io.OutputStream	setAsciiStream(long pos)
java.io.Writer	setCharacterStream(long pos)
int	setString(long pos, java.lang.String str)
int	setString(long pos, java.lang.String str, int offset, int len)
void	truncate(long len)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

EMPTY_CLOB

private static final java.lang.String EMPTY_CLOB

0 length String as initial value for empty Clobs.

See Also:

Constant Field Values

blobBuffer

private final BlobBuffer blobBuffer

The underlying BlobBuffer.

Constructor Detail

ClobImpl

ClobImpl(JtdsConnection connection)

Constructs a new empty Clob instance.

Parameters:

connection - a reference to the parent connection object

ClobImpl

ClobImpl(JtdsConnection connection,
        java.lang.String str)

Constructs a new initialized Clob instance.

Parameters:

connection - a reference to the parent connection object

str - the String object to encapsulate

Method Detail

getBlobBuffer

BlobBuffer getBlobBuffer()

Obtain this object's backing BlobBuffer object.

Returns:

the underlying BlobBuffer

getAsciiStream

public java.io.InputStream getAsciiStream()
                                   throws java.sql.SQLException

Specified by:

getAsciiStream in interface java.sql.Clob

Throws:

java.sql.SQLException

getCharacterStream

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

Specified by:

getCharacterStream in interface java.sql.Clob

Throws:

java.sql.SQLException

getSubString

public java.lang.String getSubString(long pos,
                            int length)
                              throws java.sql.SQLException

Specified by:

getSubString in interface java.sql.Clob

Throws:

java.sql.SQLException

length

public long length()
            throws java.sql.SQLException

Specified by:

length in interface java.sql.Clob

Throws:

java.sql.SQLException

position

public long position(java.lang.String searchStr,
            long start)
              throws java.sql.SQLException

Specified by:

position in interface java.sql.Clob

Throws:

java.sql.SQLException

position

public long position(java.sql.Clob searchStr,
            long start)
              throws java.sql.SQLException

Specified by:

position in interface java.sql.Clob

Throws:

java.sql.SQLException

setAsciiStream

public java.io.OutputStream setAsciiStream(long pos)
                                    throws java.sql.SQLException

Specified by:

setAsciiStream in interface java.sql.Clob

Throws:

java.sql.SQLException

setCharacterStream

public java.io.Writer setCharacterStream(long pos)
                                  throws java.sql.SQLException

Specified by:

setCharacterStream in interface java.sql.Clob

Throws:

java.sql.SQLException

setString

public int setString(long pos,
            java.lang.String str)
              throws java.sql.SQLException

Specified by:

setString in interface java.sql.Clob

Throws:

java.sql.SQLException

setString

public int setString(long pos,
            java.lang.String str,
            int offset,
            int len)
              throws java.sql.SQLException

Specified by:

setString in interface java.sql.Clob

Throws:

java.sql.SQLException

truncate

public void truncate(long len)
              throws java.sql.SQLException

Specified by:

truncate in interface java.sql.Clob

Throws:

java.sql.SQLException

free

public void free()
          throws java.sql.SQLException

Specified by:

free in interface java.sql.Clob

Throws:

java.sql.SQLException

getCharacterStream

public java.io.Reader getCharacterStream(long pos,
                                long length)
                                  throws java.sql.SQLException

Specified by:

getCharacterStream in interface java.sql.Clob

Throws:

java.sql.SQLException