public
interface
Clob
| java.sql.Clob |
 Known Indirect Subclasses
|
The mapping in the JavaTM programming language
for the SQL CLOB type.
An SQL CLOB is a built-in type
that stores a Character Large Object as a column value in a row of
a database table.
By default drivers implement a Clob object using an SQL
locator(CLOB), which means that a Clob object
contains a logical pointer to the SQL CLOB data rather than
the data itself. A Clob object is valid for the duration
of the transaction in which it was created.
The Clob interface provides methods for getting the
length of an SQL CLOB (Character Large Object) value,
for materializing a CLOB value on the client, and for
searching for a substring or CLOB object within a
CLOB value.
Methods in the interfaces ResultSet,
CallableStatement, and PreparedStatement, such as
getClob and setClob allow a programmer to
access an SQL CLOB value. In addition, this interface
has methods for updating a CLOB value.
All methods on the Clob interface must be fully implemented if the
JDBC driver supports the data type.
Public methods | |
|---|---|
abstract
void
|
free()
This method frees the |
abstract
InputStream
|
getAsciiStream()
Retrieves the |
abstract
Reader
|
getCharacterStream()
Retrieves the |
abstract
Reader
|
getCharacterStream(long pos, long length)
Returns a |
abstract
String
|
getSubString(long pos, int length)
Retrieves a copy of the specified substring
in the |
abstract
long
|
length()
Retrieves the number of characters
in the |
abstract
long
|
position(String searchstr, long start)
Retrieves the character position at which the specified substring
|
abstract
long
|
position(Clob searchstr, long start)
Retrieves the character position at which the specified
|
abstract
OutputStream
|
setAsciiStream(long pos)
Retrieves a stream to be used to write Ascii characters to the
|
abstract
Writer
|
setCharacterStream(long pos)
Retrieves a stream to be used to write a stream of Unicode characters
to the |
abstract
int
|
setString(long pos, String str, int offset, int len)
Writes |
abstract
int
|
setString(long pos, String str)
Writes the given Java |
abstract
void
|
truncate(long len)
Truncates the |
void free ()
This method frees the Clob object and releases the resources the resources
that it holds. The object is invalid once the free method
is called.
After free has been called, any attempt to invoke a
method other than free will result in a SQLException
being thrown. If free is called multiple times, the subsequent
calls to free are treated as a no-op.
| Throws | |
|---|---|
SQLException |
if an error occurs releasing the Clob's resources |
SQLFeatureNotSupportedException |
if the JDBC driver does not support this method |
InputStream getAsciiStream ()
Retrieves the CLOB value designated by this Clob
object as an ascii stream.
| Returns | |
|---|---|
InputStream |
a java.io.InputStream object containing the
CLOB data |
| Throws | |
|---|---|
SQLException |
if there is an error accessing the
CLOB value |
SQLFeatureNotSupportedException |
if the JDBC driver does not support this method |
See also:
Reader getCharacterStream ()
Retrieves the CLOB value designated by this Clob
object as a java.io.Reader object (or as a stream of
characters).
| Returns | |
|---|---|
Reader |
a java.io.Reader object containing the
CLOB data |
| Throws | |
|---|---|
SQLException |
if there is an error accessing the
CLOB value |
SQLFeatureNotSupportedException |
if the JDBC driver does not support this method |
See also:
Reader getCharacterStream (long pos, long length)
Returns a Reader object that contains a partial Clob value, starting
with the character specified by pos, which is length characters in length.
| Parameters | |
|---|---|
pos |
long:
the offset to the first character of the partial value to
be retrieved. The first character in the Clob is at position 1. |
length |
long:
the length in characters of the partial value to be retrieved. |
| Returns | |
|---|---|
Reader |
Reader through which the partial Clob value can be read. |
| Throws | |
|---|---|
SQLException |
if pos is less than 1 or if pos is greater than the number of
characters in the Clob or if pos + length is greater than the number of
characters in the Clob |
SQLFeatureNotSupportedException |
if the JDBC driver does not support this method |
String getSubString (long pos, int length)
Retrieves a copy of the specified substring
in the CLOB value
designated by this Clob object.
The substring begins at position
pos and has up to length consecutive
characters.
| Parameters | |
|---|---|
pos |
long:
the first character of the substring to be extracted.
The first character is at position 1. |
length |
int:
the number of consecutive characters to be copied;
the value for length must be 0 or greater |
| Returns | |
|---|---|
String |
a String that is the specified substring in
the CLOB value designated by this Clob object |
| Throws | |
|---|---|
SQLException |
if there is an error accessing the
CLOB value; if pos is less than 1 or length is
less than 0 |
SQLFeatureNotSupportedException |
if the JDBC driver does not support this method |
long length ()
Retrieves the number of characters
in the CLOB value
designated by this Clob object.
| Returns | |
|---|---|
long |
length of the CLOB in characters |
| Throws | |
|---|---|
SQLException |
if there is an error accessing the
length of the CLOB value |
SQLFeatureNotSupportedException |
if the JDBC driver does not support this method |
long position (String searchstr, long start)
Retrieves the character position at which the specified substring
searchstr appears in the SQL CLOB value
represented by this Clob object. The search
begins at position start.
| Parameters | |
|---|---|
searchstr |
String:
the substring for which to search |
start |
long:
the position at which to begin searching; the first position
is 1 |
| Returns | |
|---|---|
long |
the position at which the substring appears or -1 if it is not present; the first position is 1 |
| Throws | |
|---|---|
SQLException |
if there is an error accessing the
CLOB value or if pos is less than 1 |
SQLFeatureNotSupportedException |
if the JDBC driver does not support this method |
long position (Clob searchstr, long start)
Retrieves the character position at which the specified
Clob object searchstr appears in this
Clob object. The search begins at position
start.
| Parameters | |
|---|---|
searchstr |
Clob:
the Clob object for which to search |
start |
long:
the position at which to begin searching; the first
position is 1 |
| Returns | |
|---|---|
long |
the position at which the Clob object appears
or -1 if it is not present; the first position is 1 |
| Throws | |
|---|---|
SQLException |
if there is an error accessing the
CLOB value or if start is less than 1 |
SQLFeatureNotSupportedException |
if the JDBC driver does not support this method |
OutputStream setAsciiStream (long pos)
Retrieves a stream to be used to write Ascii characters to the
CLOB value that this Clob object represents,
starting at position pos. Characters written to the stream
will overwrite the existing characters
in the Clob object starting at the position
pos. If the end of the Clob value is reached
while writing characters to the stream, then the length of the Clob
value will be increased to accomodate the extra characters.
Note: If the value specified for pos
is greater then the length+1 of the CLOB value then the
behavior is undefined. Some JDBC drivers may throw a
SQLException while other drivers may support this
operation.
| Parameters | |
|---|---|
pos |
long:
the position at which to start writing to this
CLOB object; The first position is 1 |
| Returns | |
|---|---|
OutputStream |
the stream to which ASCII encoded characters can be written |
| Throws | |
|---|---|
SQLException |
if there is an error accessing the
CLOB value or if pos is less than 1 |
SQLFeatureNotSupportedException |
if the JDBC driver does not support this method |
See also:
Writer setCharacterStream (long pos)
Retrieves a stream to be used to write a stream of Unicode characters
to the CLOB value that this Clob object
represents, at position pos. Characters written to the stream
will overwrite the existing characters
in the Clob object starting at the position
pos. If the end of the Clob value is reached
while writing characters to the stream, then the length of the Clob
value will be increased to accomodate the extra characters.
Note: If the value specified for pos
is greater then the length+1 of the CLOB value then the
behavior is undefined. Some JDBC drivers may throw a
SQLException while other drivers may support this
operation.
| Parameters | |
|---|---|
pos |
long:
the position at which to start writing to the
CLOB value; The first position is 1 |
| Returns | |
|---|---|
Writer |
a stream to which Unicode encoded characters can be written |
| Throws | |
|---|---|
SQLException |
if there is an error accessing the
CLOB value or if pos is less than 1 |
SQLFeatureNotSupportedException |
if the JDBC driver does not support this method |
See also:
Developers
int setString (long pos,
String str,
int offset,
int len)
Writes len characters of str, starting
at character offset, to the CLOB value
that this Clob represents. The string will overwrite the existing characters
in the Clob object starting at the position
pos. If the end of the Clob value is reached
while writing the given string, then the length of the Clob
value will be increased to accomodate the extra characters.
Note: If the value specified for pos
is greater then the length+1 of the CLOB value then the
behavior is undefined. Some JDBC drivers may throw a
SQLException while other drivers may support this
operation.
| Parameters | |
|---|---|
pos |
long:
the position at which to start writing to this
CLOB object; The first position is 1 |
str |
String:
the string to be written to the CLOB
value that this Clob object represents |
offset |
int:
the offset into str to start reading
the characters to be written |
len |
int:
the number of characters to be written |
| Returns | |
|---|---|
int |
the number of characters written |
| Throws | |
|---|---|
SQLException |
if there is an error accessing the
CLOB value or if pos is less than 1 |
SQLFeatureNotSupportedException |
if the JDBC driver does not support this method |
int setString (long pos,
String str)
Writes the given Java String to the CLOB
value that this Clob object designates at the position
pos. The string will overwrite the existing characters
in the Clob object starting at the position
pos. If the end of the Clob value is reached
while writing the given string, then the length of the Clob
value will be increased to accomodate the extra characters.
Note: If the value specified for pos
is greater then the length+1 of the CLOB value then the
behavior is undefined. Some JDBC drivers may throw a
SQLException while other drivers may support this
operation.
| Parameters | |
|---|---|
pos |
long:
the position at which to start writing to the CLOB
value that this Clob object represents;
The first position is 1 |
str |
String:
the string to be written to the CLOB
value that this Clob designates |
| Returns | |
|---|---|
int |
the number of characters written |
| Throws | |
|---|---|
SQLException |
if there is an error accessing the
CLOB value or if pos is less than 1 |
SQLFeatureNotSupportedException |
if the JDBC driver does not support this method |
void truncate (long len)
Truncates the CLOB value that this Clob
designates to have a length of len
characters.
Note: If the value specified for pos
is greater then the length+1 of the CLOB value then the
behavior is undefined. Some JDBC drivers may throw a
SQLException while other drivers may support this
operation.
| Parameters | |
|---|---|
len |
long:
the length, in characters, to which the CLOB value
should be truncated |
| Throws | |
|---|---|
SQLException |
if there is an error accessing the
CLOB value or if len is less than 0 |
SQLFeatureNotSupportedException |
if the JDBC driver does not support this method |