/*
* @(#)Clob.java 1.35 06/08/12
*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
package java.sql;
import java.io.Reader;
/**
* The mapping in the Java<sup><font size=-2>TM</font></sup> programming language
* for the SQL <code>CLOB</code> type.
* An SQL <code>CLOB</code> 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 <code>Clob</code> object using an SQL
* <code>locator(CLOB)</code>, which means that a <code>Clob</code> object
* contains a logical pointer to the SQL <code>CLOB</code> data rather than
* the data itself. A <code>Clob</code> object is valid for the duration
* of the transaction in which it was created.
* <P>The <code>Clob</code> interface provides methods for getting the
* length of an SQL <code>CLOB</code> (Character Large Object) value,
* for materializing a <code>CLOB</code> value on the client, and for
* searching for a substring or <code>CLOB</code> object within a
* <code>CLOB</code> value.
* Methods in the interfaces {@link ResultSet},
* {@link CallableStatement}, and {@link PreparedStatement}, such as
* <code>getClob</code> and <code>setClob</code> allow a programmer to
* access an SQL <code>CLOB</code> value. In addition, this interface
* has methods for updating a <code>CLOB</code> value.
* <p>
* All methods on the <code>Clob</code> interface must be fully implemented if the
* JDBC driver supports the data type.
*
* @since 1.2
*/
public interface Clob {
/**
* Retrieves the number of characters
* in the <code>CLOB</code> value
* designated by this <code>Clob</code> object.
*
* @return length of the <code>CLOB</code> in characters
* @exception SQLException if there is an error accessing the
* length of the <code>CLOB</code> value
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @since 1.2
*/
long length() throws SQLException;
/**
* Retrieves a copy of the specified substring
* in the <code>CLOB</code> value
* designated by this <code>Clob</code> object.
* The substring begins at position
* <code>pos</code> and has up to <code>length</code> consecutive
* characters.
*
* @param pos the first character of the substring to be extracted.
* The first character is at position 1.
* @param length the number of consecutive characters to be copied;
* the value for length must be 0 or greater
* @return a <code>String</code> that is the specified substring in
* the <code>CLOB</code> value designated by this <code>Clob</code> object
* @exception SQLException if there is an error accessing the
* <code>CLOB</code> value; if pos is less than 1 or length is
* less than 0
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @since 1.2
*/
String getSubString(long pos, int length) throws SQLException;
/**
* Retrieves the <code>CLOB</code> value designated by this <code>Clob</code>
* object as a <code>java.io.Reader</code> object (or as a stream of
* characters).
*
* @return a <code>java.io.Reader</code> object containing the
* <code>CLOB</code> data
* @exception SQLException if there is an error accessing the
* <code>CLOB</code> value
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @see #setCharacterStream
* @since 1.2
*/
java.io.Reader getCharacterStream() throws SQLException;
/**
* Retrieves the <code>CLOB</code> value designated by this <code>Clob</code>
* object as an ascii stream.
*
* @return a <code>java.io.InputStream</code> object containing the
* <code>CLOB</code> data
* @exception SQLException if there is an error accessing the
* <code>CLOB</code> value
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @see #setAsciiStream
* @since 1.2
*/
java.io.InputStream getAsciiStream() throws SQLException;
/**
* Retrieves the character position at which the specified substring
* <code>searchstr</code> appears in the SQL <code>CLOB</code> value
* represented by this <code>Clob</code> object. The search
* begins at position <code>start</code>.
*
* @param searchstr the substring for which to search
* @param start the position at which to begin searching; the first position
* is 1
* @return the position at which the substring appears or -1 if it is not
* present; the first position is 1
* @exception SQLException if there is an error accessing the
* <code>CLOB</code> value or if pos is less than 1
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @since 1.2
*/
long position(String searchstr, long start) throws SQLException;
/**
* Retrieves the character position at which the specified
* <code>Clob</code> object <code>searchstr</code> appears in this
* <code>Clob</code> object. The search begins at position
* <code>start</code>.
*
* @param searchstr the <code>Clob</code> object for which to search
* @param start the position at which to begin searching; the first
* position is 1
* @return the position at which the <code>Clob</code> object appears
* or -1 if it is not present; the first position is 1
* @exception SQLException if there is an error accessing the
* <code>CLOB</code> value or if start is less than 1
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @since 1.2
*/
long position(Clob searchstr, long start) throws SQLException;
//---------------------------- jdbc 3.0 -----------------------------------
/**
* Writes the given Java <code>String</code> to the <code>CLOB</code>
* value that this <code>Clob</code> object designates at the position
* <code>pos</code>. The string will overwrite the existing characters
* in the <code>Clob</code> object starting at the position
* <code>pos</code>. If the end of the <code>Clob</code> value is reached
* while writing the given string, then the length of the <code>Clob</code>
* value will be increased to accomodate the extra characters.
* <p>
* <b>Note:</b> If the value specified for <code>pos</code>
* is greater then the length+1 of the <code>CLOB</code> value then the
* behavior is undefined. Some JDBC drivers may throw a
* <code>SQLException</code> while other drivers may support this
* operation.
*
* @param pos the position at which to start writing to the <code>CLOB</code>
* value that this <code>Clob</code> object represents;
* The first position is 1
* @param str the string to be written to the <code>CLOB</code>
* value that this <code>Clob</code> designates
* @return the number of characters written
* @exception SQLException if there is an error accessing the
* <code>CLOB</code> value or if pos is less than 1
*
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @since 1.4
*/
int setString(long pos, String str) throws SQLException;
/**
* Writes <code>len</code> characters of <code>str</code>, starting
* at character <code>offset</code>, to the <code>CLOB</code> value
* that this <code>Clob</code> represents. The string will overwrite the existing characters
* in the <code>Clob</code> object starting at the position
* <code>pos</code>. If the end of the <code>Clob</code> value is reached
* while writing the given string, then the length of the <code>Clob</code>
* value will be increased to accomodate the extra characters.
* <p>
* <b>Note:</b> If the value specified for <code>pos</code>
* is greater then the length+1 of the <code>CLOB</code> value then the
* behavior is undefined. Some JDBC drivers may throw a
* <code>SQLException</code> while other drivers may support this
* operation.
*
* @param pos the position at which to start writing to this
* <code>CLOB</code> object; The first position is 1
* @param str the string to be written to the <code>CLOB</code>
* value that this <code>Clob</code> object represents
* @param offset the offset into <code>str</code> to start reading
* the characters to be written
* @param len the number of characters to be written
* @return the number of characters written
* @exception SQLException if there is an error accessing the
* <code>CLOB</code> value or if pos is less than 1
*
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @since 1.4
*/
int setString(long pos, String str, int offset, int len) throws SQLException;
/**
* Retrieves a stream to be used to write Ascii characters to the
* <code>CLOB</code> value that this <code>Clob</code> object represents,
* starting at position <code>pos</code>. Characters written to the stream
* will overwrite the existing characters
* in the <code>Clob</code> object starting at the position
* <code>pos</code>. If the end of the <code>Clob</code> value is reached
* while writing characters to the stream, then the length of the <code>Clob</code>
* value will be increased to accomodate the extra characters.
* <p>
* <b>Note:</b> If the value specified for <code>pos</code>
* is greater then the length+1 of the <code>CLOB</code> value then the
* behavior is undefined. Some JDBC drivers may throw a
* <code>SQLException</code> while other drivers may support this
* operation.
*
* @param pos the position at which to start writing to this
* <code>CLOB</code> object; The first position is 1
* @return the stream to which ASCII encoded characters can be written
* @exception SQLException if there is an error accessing the
* <code>CLOB</code> value or if pos is less than 1
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @see #getAsciiStream
*
* @since 1.4
*/
java.io.OutputStream setAsciiStream(long pos) throws SQLException;
/**
* Retrieves a stream to be used to write a stream of Unicode characters
* to the <code>CLOB</code> value that this <code>Clob</code> object
* represents, at position <code>pos</code>. Characters written to the stream
* will overwrite the existing characters
* in the <code>Clob</code> object starting at the position
* <code>pos</code>. If the end of the <code>Clob</code> value is reached
* while writing characters to the stream, then the length of the <code>Clob</code>
* value will be increased to accomodate the extra characters.
* <p>
* <b>Note:</b> If the value specified for <code>pos</code>
* is greater then the length+1 of the <code>CLOB</code> value then the
* behavior is undefined. Some JDBC drivers may throw a
* <code>SQLException</code> while other drivers may support this
* operation.
*
* @param pos the position at which to start writing to the
* <code>CLOB</code> value; The first position is 1
*
* @return a stream to which Unicode encoded characters can be written
* @exception SQLException if there is an error accessing the
* <code>CLOB</code> value or if pos is less than 1
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @see #getCharacterStream
*
* @since 1.4
*/
java.io.Writer setCharacterStream(long pos) throws SQLException;
/**
* Truncates the <code>CLOB</code> value that this <code>Clob</code>
* designates to have a length of <code>len</code>
* characters.
* <p>
* <b>Note:</b> If the value specified for <code>pos</code>
* is greater then the length+1 of the <code>CLOB</code> value then the
* behavior is undefined. Some JDBC drivers may throw a
* <code>SQLException</code> while other drivers may support this
* operation.
*
* @param len the length, in characters, to which the <code>CLOB</code> value
* should be truncated
* @exception SQLException if there is an error accessing the
* <code>CLOB</code> value or if len is less than 0
*
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @since 1.4
*/
void truncate(long len) throws SQLException;
/**
* This method frees the <code>Clob</code> object and releases the resources the resources
* that it holds. The object is invalid once the <code>free</code> method
* is called.
* <p>
* After <code>free</code> has been called, any attempt to invoke a
* method other than <code>free</code> will result in a <code>SQLException</code>
* being thrown. If <code>free</code> is called multiple times, the subsequent
* calls to <code>free</code> are treated as a no-op.
* <p>
* @throws SQLException if an error occurs releasing
* the Clob's resources
*
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @since 1.6
*/
void free() throws SQLException;
/**
* Returns a <code>Reader</code> object that contains a partial <code>Clob</code> value, starting
* with the character specified by pos, which is length characters in length.
*
* @param pos the offset to the first character of the partial value to
* be retrieved. The first character in the Clob is at position 1.
* @param length the length in characters of the partial value to be retrieved.
* @return <code>Reader</code> through which the partial <code>Clob</code> value can be read.
* @throws SQLException if pos is less than 1 or if pos is greater than the number of
* characters in the <code>Clob</code> or if pos + length is greater than the number of
* characters in the <code>Clob</code>
*
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @since 1.6
*/
Reader getCharacterStream(long pos, long length) throws SQLException;
}
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