content: /*
   * Copyright (c) 1998, 2006, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
   * particular file as subject to the "Classpath" exception as provided
   * by Oracle in the LICENSE file that accompanied this code.
   *
   * This code is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   * or visit www.oracle.com if you need additional information or have any
   * questions.
   */
  
  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
     */
    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;
  
  }
  