java.sql
Interface Clob


public interface Clob

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.

Since:
1.2

Method Summary
 InputStream getAsciiStream()
          Retrieves the CLOB value designated by this Clob object as an ascii stream.
 Reader getCharacterStream()
          Retrieves the CLOB value designated by this Clob object as a java.io.Reader object (or as a stream of characters).
 String getSubString(long pos, int length)
          Retrieves a copy of the specified substring in the CLOB value designated by this Clob object.
 long length()
          Retrieves the number of characters in the CLOB value designated by this Clob object.
 long position(Clob searchstr, long start)
          Retrieves the character position at which the specified Clob object searchstr appears in this Clob object.
 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.
 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.
 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.
 int setString(long pos, String str)
          Writes the given Java String to the CLOB value that this Clob object designates at the position pos.
 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.
 void truncate(long len)
          Truncates the CLOB value that this Clob designates to have a length of len characters.
 

Method Detail

length

public long length()
            throws SQLException
Retrieves the number of characters in the CLOB value designated by this Clob object.

Returns:
length of the CLOB in characters
Throws:
SQLException - if there is an error accessing the length of the CLOB value
Since:
1.2

getSubString

public String getSubString(long pos,
                           int length)
                    throws SQLException
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 - the first character of the substring to be extracted. The first character is at position 1.
length - the number of consecutive characters to be copied
Returns:
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
Since:
1.2

getCharacterStream

public Reader getCharacterStream()
                          throws SQLException
Retrieves the CLOB value designated by this Clob object as a java.io.Reader object (or as a stream of characters).

Returns:
a java.io.Reader object containing the CLOB data
Throws:
SQLException - if there is an error accessing the CLOB value
Since:
1.2
See Also:
setCharacterStream(long)

getAsciiStream

public InputStream getAsciiStream()
                           throws SQLException
Retrieves the CLOB value designated by this Clob object as an ascii stream.

Returns:
a java.io.InputStream object containing the CLOB data
Throws:
SQLException - if there is an error accessing the CLOB value
Since:
1.2
See Also:
setAsciiStream(long)

position

public long position(String searchstr,
                     long start)
              throws SQLException
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 - the substring for which to search
start - the position at which to begin searching; the first position is 1
Returns:
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
Since:
1.2

position

public long position(Clob searchstr,
                     long start)
              throws SQLException
Retrieves the character position at which the specified Clob object searchstr appears in this Clob object. The search begins at position start.

Parameters:
searchstr - the Clob object for which to search
start - the position at which to begin searching; the first position is 1
Returns:
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
Since:
1.2

setString

public int setString(long pos,
                     String str)
              throws SQLException
Writes the given Java String to the CLOB value that this Clob object designates at the position pos.

Parameters:
pos - the position at which to start writing to the CLOB value that this Clob object represents
str - the string to be written to the CLOB value that this Clob designates
Returns:
the number of characters written
Throws:
SQLException - if there is an error accessing the CLOB value
Since:
1.4

setString

public int setString(long pos,
                     String str,
                     int offset,
                     int len)
              throws SQLException
Writes len characters of str, starting at character offset, to the CLOB value that this Clob represents.

Parameters:
pos - the position at which to start writing to this CLOB object
str - the string to be written to the CLOB value that this Clob object represents
offset - the offset into str to start reading the characters to be written
len - the number of characters to be written
Returns:
the number of characters written
Throws:
SQLException - if there is an error accessing the CLOB value
Since:
1.4

setAsciiStream

public OutputStream setAsciiStream(long pos)
                            throws SQLException
Retrieves a stream to be used to write Ascii characters to the CLOB value that this Clob object represents, starting at position pos.

Parameters:
pos - the position at which to start writing to this CLOB object
Returns:
the stream to which ASCII encoded characters can be written
Throws:
SQLException - if there is an error accessing the CLOB value
Since:
1.4
See Also:
getAsciiStream()

setCharacterStream

public Writer setCharacterStream(long pos)
                          throws SQLException
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.

Parameters:
pos - the position at which to start writing to the CLOB value
Returns:
a stream to which Unicode encoded characters can be written
Throws:
SQLException - if there is an error accessing the CLOB value
Since:
1.4
See Also:
getCharacterStream()

truncate

public void truncate(long len)
              throws SQLException
Truncates the CLOB value that this Clob designates to have a length of len characters.

Parameters:
len - the length, in bytes, to which the CLOB value should be truncated
Throws:
SQLException - if there is an error accessing the CLOB value
Since:
1.4